CN110820139A

CN110820139A - Synchronous control method of loom and loom thereof

Info

Publication number: CN110820139A
Application number: CN201910683192.3A
Authority: CN
Inventors: 伊藤直幸
Original assignee: Tsudakoma Industrial Co Ltd
Current assignee: Tsudakoma Corp
Priority date: 2018-08-09
Filing date: 2019-07-26
Publication date: 2020-02-21
Anticipated expiration: 2039-07-26
Also published as: CN110820139B; EP3608458B1; JP7158952B2; EP3608458A1; JP2020026581A

Abstract

The invention discloses a synchronous control method of a loom and the loom. The loom is provided with a shedding motor independent of a main shaft motor of the loom as a driving source, and each heddle is displaced in the vertical direction by driving a single driving shaft common to all heddles by the shedding motor, and the synchronous control method of the loom is characterized in that at least when the loom is in steady operation, the rotation amount of the driving shaft in each loom cycle is detected, and the driving of the main shaft motor is controlled in such a manner that the main shaft of the loom rotates synchronously with respect to the driving shaft in accordance with a detection signal corresponding to the rotation amount. According to the present invention, in the loom, it is not necessary to use a high-output synchronous motor as the shedding motor, and the overall cost of the loom can be controlled to be low.

Description

Synchronous control method of loom and loom thereof

Technical Field

The present invention relates to a synchronous control method for a loom and a loom equipped with a shedding device having a shedding motor independent of a spindle motor of the loom as a drive source, and displacing each heddle in the vertical direction by driving a single drive shaft common to all heddles by the shedding motor.

Background

In a loom, a jacquard shedding device is known as a shedding device for shedding warp yarns.

The shedding device for a jacquard is configured such that, in order to open warp yarns passing through the respective heddles, the respective heddles are individually displaced upward or downward in accordance with a predetermined pattern by rotationally driving a single drive shaft common to all the heddles.

In a loom equipped with such a jacquard shedding device, a drive shaft of the shedding device is generally rotationally driven so that the drive shaft rotates by one-half of a revolution for every one revolution of a main shaft of the loom. Conventionally, as a structure for rotationally driving the drive shaft in this manner, there are two types of structures, a mechanical structure in which the main shaft is used as a drive source, and an electrical structure in which a dedicated motor is used as a drive source.

In the former mechanical structure, the loom is configured such that a drive shaft of the shedding device and a main shaft of the loom are mechanically coupled by a shaft, a chain, or the like. However, this structure has a problem that many mechanical parts are required and maintenance is very complicated.

On the other hand, in the latter electric structure, the loom adopts a structure in which the drive shaft of the shedding device is driven by a dedicated drive motor (shedding motor) independent of the spindle motor of the loom. Further, according to this configuration, since the connection between the drive shaft of the shedding device and the main shaft of the loom is electrically connected, there are advantages such as reduction in the number of machine parts and improvement in maintainability, as compared with the above-described mechanical configuration. Further, patent document 1 below discloses a loom that employs such an electrical structure for connection between a drive shaft of a jacquard shedding device and a main shaft of the loom.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 3-249233

Disclosure of Invention

Problems to be solved by the invention

However, in the loom described in patent document 1, the drive of the shedding motor is synchronously controlled so that the drive shaft and the main shaft of the shedding device rotate synchronously.

In addition, in the shedding device, since the healds through which the warp yarn maintained at a predetermined tension passes are displaced upward or downward, a large load is applied to the drive shaft. In addition to this, jacquard shedding devices are commonly used for the weaving of complex weave-patterns of textiles. Therefore, in the jacquard shedding device, the heddles are driven in a complicated pattern, and accordingly, the number of the heddles displaced upward and the number of the heddles displaced downward greatly vary in many cases per loom cycle. Also in this case, the load acting on the drive shaft varies greatly during each loom cycle.

Therefore, when the drive of the shedding motor is synchronously controlled as described above, it is necessary to control the drive of the shedding motor so as not to delay or advance the rotation of the drive shaft by being dragged by the load fluctuation.

The main shaft of the loom is connected to the beating-up device, and a load caused by the beating-up operation (oscillation of the reed) acts on the main shaft of the loom. Thus, the rotation of the main shaft is not constant and varies in one rotation (in one cycle of the loom). Therefore, it is necessary to perform synchronous control of the shedding motor so that the rotation of the drive shaft follows the rotation of the spindle which changes in this manner.

Therefore, in a jacquard shedding device having a dedicated drive motor (shedding motor) as a drive source, a high-output synchronous motor (e.g., servo motor) capable of such synchronous control is generally used as the shedding motor. However, such a synchronous motor is very expensive, which leads to an increase in the cost of a loom provided with a jacquard shedding device.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a synchronization control method for a loom and a loom using the same, which can reduce the overall cost of the loom without using such a high-output synchronization motor as a shedding motor in the loom as described above.

Means for solving the problems

The present invention is premised on a loom including a shedding motor as a drive source, the shedding motor being independent of a spindle motor of the loom, and each of heddles being displaced in the vertical direction by a single drive shaft common to all the heddles being driven by the shedding motor.

In the synchronous control method of a loom according to the present invention, at least when the loom is in a steady operation, the rotation amount of the drive shaft in each loom cycle is detected, and the drive of the spindle motor is controlled so that the spindle of the loom rotates synchronously with respect to the drive shaft in accordance with a detection signal corresponding to the rotation amount.

In addition, the synchronization control method of the loom of the present invention may be configured as follows: the drive control of the spindle motor includes: the method includes rotating the spindle within a preset time period from a time point at which a target rotation amount is obtained, the target rotation amount being obtained based on the rotation amount of the drive shaft detected for each preset time period, detecting an actual rotation angle of the spindle at a time point at which it is assumed that the rotation angle of the spindle reaches a set angle, the set angle being a predetermined rotation angle of the spindle, comparing the detected actual rotation angle with the set angle, obtaining a deviation of the actual rotation angle from the set angle, and correcting the target rotation amount obtained for the preset time period after the time point based on the deviation at the time point at which the deviation is obtained a predetermined number of times.

Further, the synchronization control method of the loom of the present invention may adopt the following method: the control parameter for controlling the spindle motor is changed according to the load acting on the drive shaft along with the displacement of the heald.

Further, the loom of the present invention for realizing the synchronous control method is premised on a shedding device that has a shedding motor independent of a spindle motor of the loom as a drive source and displaces each of the heddles in the up-down direction by driving a single drive shaft common to all the heddles by the shedding motor, and a spindle control device that controls driving of the spindle motor.

Further, a loom according to the present invention includes: a rotation detecting device that detects a rotation amount of the drive shaft in each loom cycle at least when the loom is stably operated; and a synchronization control device that obtains a rotation amount of a main shaft of a loom so that the main shaft is synchronized with the drive shaft in accordance with a detection signal output from the rotation detection device, and outputs a rotation command signal based on the obtained rotation amount of the main shaft to the main shaft control device.

In addition, the loom of the present invention may adopt the following modes: the synchronization control device includes: an arithmetic unit that obtains a target rotation amount of the spindle rotation in the set time period from a time point at which the target rotation amount is obtained based on the rotation amount of the drive shaft detected for each set time period set in advance; an angle detector that obtains an actual rotation angle of the main shaft at a time point when it is assumed that the rotation angle of the main shaft reaches a set angle, the set angle being a predetermined rotation angle of the main shaft set in advance; and a comparator that compares the actual rotation angle obtained by the angle detector with the set angle and obtains a deviation of the actual rotation angle from the set angle, wherein the arithmetic unit includes a corrector that corrects the target rotation amount obtained for the set time period after a time point at which the deviation is obtained a predetermined number of times, based on the deviation.

The loom of the present invention may adopt the following modes: the synchronous control device has a function of changing a control parameter used for controlling the spindle motor according to a load acting on the drive shaft along with the displacement of the heald.

Effects of the invention

According to the present invention, since the synchronous control of the drive shaft and the main shaft is performed so that the rotation of the main shaft of the loom is synchronized with the rotation of the drive shaft of the shedding device, it is not necessary to require the shedding motor to have a performance that can maintain the synchronous state of the drive shaft that applies a large load to the main shaft that rotationally fluctuates as described above during weaving. Thus, as the shedding motor, an inexpensive induction motor can be used without using an expensive synchronous motor, and as a result, the cost of the shedding apparatus can be reduced.

In addition, since the rotation of the spindle is synchronized with the rotation of the drive shaft, the spindle motor needs to employ a synchronous motor, and thus the cost of the spindle motor increases. However, when comparing the load acting on the drive shaft (load accompanying the displacement of the healds) with the load acting on the main shaft (load accompanying the swinging of the reed), the load acting on the main shaft is about half of the load acting on the drive shaft and is very small. Therefore, even if the spindle motor employs a synchronous motor, the spindle motor can be an inexpensive motor having an output power smaller than that of the shedding motor in the conventional loom. Therefore, although the cost of the spindle motor itself is increased, the cost of the loom as a whole can be reduced as compared with the case where the shedding motor is a synchronous motor.

Further, in the present invention, by controlling the driving of the spindle motor in such a manner as to correct the target rotation amount of the spindle, even in the case where a deviation in rotation amount occurs between the drive shaft and the spindle, it is possible to maintain a state in which the rotation of the spindle is more accurately synchronized with the rotation of the drive shaft by eliminating the deviation.

In detail, in the present invention, although the rotation of the main shaft is synchronized with the rotation of the drive shaft, a deviation in the amount of rotation may occur between the drive shaft and the main shaft for some reason (e.g., abnormal vibration of the loom, etc.).

Therefore, the actual rotation angle of the main shaft at the time point when the rotation angle of the main shaft is assumed to reach the set angle is detected, and the deviation (deviation) of the rotation amount is obtained by comparing the detected actual rotation angle with the set angle. In addition, the deviation can be eliminated by controlling the driving of the spindle motor so as to correct the target rotation amount of the spindle based on the obtained deviation. Further, as a result, a state in which the main shaft and the drive shaft are more accurately synchronized can be maintained.

In the present invention, the load on the spindle motor can be suppressed by changing the control parameter used for controlling the spindle motor in accordance with the load acting on the drive shaft.

In detail, as described above, the rotation of the drive shaft fluctuates in each loom cycle as a result of the variation in the load acting on the drive shaft in each loom cycle. In the present invention, the rotation of the spindle is made to follow the rotation of the fluctuating drive shaft, and therefore, if the fluctuation is large, the load on the spindle motor becomes large.

Therefore, in a loom cycle in which the load acting on the drive shaft is large, the control parameter is changed so that the following performance of the rotation of the main shaft with respect to the rotation of the drive shaft is low, and when the rotation fluctuation of the drive shaft is large, the load on the main shaft motor can be suppressed.

Drawings

Fig. 1 is a block diagram showing an example of the structure of a loom of the present invention;

fig. 2 is a block diagram showing an example of the configuration of the synchronization control device; and

fig. 3 is a block diagram showing another example of the configuration of the synchronization control device.

Description of the symbols

1-weaving device, 11-weaving machine body, 12-main shaft, 13-main shaft motor, 14-main shaft control device, 15-main shaft side encoder, 16-input setting device, 17-drive transmission mechanism, 2-jacquard shedding device, 21-jacquard machine body, 22-drive shaft, 23-shedding motor, 24-shedding control device, 25-shedding side encoder, 26-drive transmission mechanism, 3-synchronous control device, 31-arithmetic unit, 32-discriminator, 33-angle detector, 34-comparator, 35-rotation amount arithmetic unit, 36-corrector, 37-parameter changer, Rm-main shaft side detection signal, Rd-shedding side detection signal, Rc-rotation command signal, T0-reference signal, θ -angle signal, △ θ -deviation signal, C-correction signal, S-step signal, G-gain signal.

Detailed Description

Fig. 1 shows an example of a loom to which the present invention is applied, and the loom in this embodiment is constituted by a weaving device 1 including a loom main body 11 provided with a weft insertion device, a beating-up device, and the like (not shown), and a jacquard shedding device 2 including a jacquard main body 21 disposed above the weaving device 1 (loom main body 11) as a shedding device for giving shedding motion to warp yarns. However, in this jacquard shedding device 2, a dedicated motor (shedding motor 23) independent of the motor (spindle motor 13) of the loom main body 11 is used as a drive source, and the jacquard main body 21 is mechanically independent of the loom main body 11.

The weaving device 1 includes a main shaft 12, a loom main body 11 as a part to be woven by the above-described weft insertion device, and the like, a main shaft motor 13 for rotationally driving the main shaft 12 in the loom main body 11, and a main shaft control device 14 for controlling rotation of the main shaft motor 13. The weaving device 1 includes a spindle-side encoder 15 for detecting the rotation amount of the spindle 12 that is rotationally driven as described above, and an input setting device 16 for inputting respective setting values for setting weaving conditions and the like.

The spindle motor 13 is connected to the spindle 12 in the loom main body 11 via a drive transmission mechanism 17 such as a reduction gear. In the present embodiment, the spindle motor 13 is constituted by a synchronous motor. Incidentally, as an example of the synchronous machine, an IPM machine can be cited. The spindle 12 is rotationally driven by such a spindle motor 13. In addition, the beating-up device included in the loom main body 11 is configured such that a reed connected to the main shaft 12 is driven to swing by rotation of the main shaft 12. Therefore, in this beating-up device, the main shaft 12 is rotationally driven as described above, and the reed is driven to swing, thereby performing beating-up motion.

In the weaving device 1, although weaving is performed in accordance with weft insertion by the weft insertion device described above, the weft insertion device or other devices related to weaving are controlled in accordance with the detected rotation angle of the main shaft 12 (hereinafter referred to as "crank angle"). Therefore, the weaving device 1 includes a spindle-side encoder 15 for detecting the crank angle. The spindle-side encoder 15 outputs a detection signal (hereinafter referred to as a "spindle-side detection signal Rm") corresponding to the detected crank angle to a device controller (not shown) that controls the operation of each device.

The spindle-side detection signal Rm is also output to a spindle controller 14 that drives the spindle motor 13. On this basis, the spindle control device 14 is configured to control the driving of the spindle motor 13 based on an input rotation command signal Rc to be described later and a spindle-side detection signal Rm from the spindle-side encoder 15.

The input setting device 16 is a device for inputting respective set values for setting weaving conditions in the weaving. The weaving conditions include a set rotation speed that is a rotation speed of the loom (rotation speed during steady operation) assumed (set) for weaving at that time, and shedding parameters of the warp yarns that set the positions (upper and lower) of the warp yarns for each loom cycle. Incidentally, the input setting device 16 is configured to have, for example, a touch screen type screen display device, and the above-described respective setting values can be input and set through a setting screen or the like displayed on the screen display device. The input setting device 16 is connected to the loom main body 11, and is configured to transmit each set value input and set to each device controller in the corresponding loom main body 11.

The jacquard shedding device 2 includes: a plurality of heddles (not shown) in which the number of warp yarns is set to correspond to the number of warp yarns and the warp yarns are inserted through the heddles; a jacquard main body 21 that forms a warp opening by displacing the heald in the vertical direction; a shedding motor 23 as a drive source of the jacquard main body 21; and a shedding control device 24 that controls rotation of the shedding motor 23. In addition, the jacquard shedding device 2 includes an opening-side encoder 25 as a rotation amount detection means, and the opening-side encoder 25 detects the rotation amount of the drive shaft 22 of the jacquard main body 21 rotationally driven by the shedding motor 23.

The jacquard main body 21 includes a single drive shaft 22, and is configured to displace the healds in the vertical direction by rotationally driving the drive shaft 22. That is, the single drive shaft 22 in this jacquard body 21 is common in all heddles. The drive shaft 22 is connected to the shedding motor 23 via a drive transmission mechanism 26 such as a reduction gear. The opening motor 23 is composed of an induction motor in the present embodiment. Further, although the structure of the jacquard main body 21 itself is well known and detailed description thereof is omitted, the jacquard main body 21 has a drive mechanism (not shown) including a structure for converting the rotation of the drive shaft 22 into the vertical movement. The drive mechanism is connected to the heddles via a cord (wire) provided corresponding to the heddles and connected to the heddles. The drive mechanism is configured to displace the healds in the vertical direction in accordance with the rotation of the drive shaft 22.

The shedding control device 24 is connected to the input setting device 16 on the weaving device 1 side, and also connected to the opening side encoder 25. In addition, the set rotation speed and the shedding parameters, which are the weaving conditions, are transmitted from the input setting device 16 to the shedding control device 24. In addition, a detection signal (hereinafter referred to as "opening-side detection signal Rd") corresponding to the amount of rotation of the drive shaft 22 detected by the opening-side encoder 25 is output from the opening-side encoder 25 to the opening control device 24. In the present embodiment, the driving mechanism is configured to cause each heddle to perform weaving operation for two loom circulation amounts when the driving shaft 22 rotates one revolution. Therefore, in the present embodiment, the drive shaft 22 is rotationally driven so as to rotate one-half of a revolution in one cycle of the loom. Therefore, the shedding controller 24 is configured to control the driving of the shedding motor 23 based on the set rotation speed and the opening side detection signal Rd so that the driving shaft 22 is driven at one-half of the set rotation speed. The shedding control device 24 is configured to control the jacquard main body 21 (drive mechanism) so that the healds are displaced in accordance with the shedding pattern.

In the loom including the weaving device 1 and the jacquard shedding device 2 described above, in the present invention, the loom includes the synchronous control device 3 that finds the rotation amount of the main shaft 12 in such a manner that the main shaft 12 in the loom main body 11 of the weaving device 1 rotates in synchronization with the drive shaft 22 in the jacquard main body 21 of the jacquard shedding device 2 in accordance with the opening side detection signal Rd detected by the rotation detection device (opening side encoder 25) in steady operation, and outputs the rotation command signal Rc based on the found rotation amount of the main shaft 12 to the main shaft control device 14.

As shown in fig. 1, the synchronization control device 3 is connected at its input end to the opening-side encoder 25 and the spindle-side encoder 15, and is connected at its output end to the spindle control device 14. As shown in fig. 2, the synchronization control device 3 includes components such as an arithmetic unit 31, a discriminator 32, an angle detector 33, and a comparator 34. Details of these components are as follows.

As shown in fig. 2, the arithmetic unit 31 includes a rotation amount arithmetic unit 35 and a corrector 36. The rotation amount calculator 35 is connected to the opening-side encoder 25 and the corrector 36 on the input side thereof, and is connected to the spindle control device 14 on the output side thereof. The corrector 36 is connected to the comparator 34 on its input side and to the rotation amount calculator 35 on its output side.

The rotation amount calculator 35 is configured to calculate the rotation amount of the drive shaft 22 (hereinafter, referred to as "drive shaft rotation amount") in each preset time period (for example, set to 0.5 msec. and hereinafter, referred to as "set time period") based on the opening-side detection signal Rd output from the opening-side encoder 25 in the set time period. The rotation amount calculator 35 is configured to obtain a target rotation amount, which is a rotation amount by which the main shaft 12 should be rotationally driven, between the obtained drive shaft rotation amount and the next input of the opening side detection signal Rd (in the set time period), every time the drive shaft rotation amount is obtained in this manner (that is, every set time period).

However, the target rotation amount is a rotation amount for causing the rotation of the main shaft 12 to follow the rotation of the drive shaft 22, and is a rotation amount by which the rotation angle of the main shaft 12 reaches a rotation angle corresponding to the rotation angle of the drive shaft 22 at the time point when the drive shaft rotation amount is obtained after the next drive shaft rotation amount is obtained by 0.5msec (after the above-described set time period). The rotation angle corresponding to the rotation angle of the drive shaft 22 is obtained by doubling the rotation angle of the drive shaft 22. Therefore, the target rotation amount is obtained by doubling the rotation amount of the drive shaft.

In detail, in the weaving device 1, generally, one weaving operation (operation for weaving accompanied by one weft insertion, beat-up, and the like) is performed by rotating the main shaft 12 once. In weaving by a loom, this one weaving operation is repeated, the one weaving operation corresponding to one cycle of the loom (one loom cycle (also referred to as one weaving cycle)). On the other hand, as described above, in the jacquard shedding device 2 of the present embodiment, each heddle is operated for two loom cycles per one rotation of the drive shaft 22. In other words, in jacquard shedding device 2, the operation of one weaving cycle is performed by one-half rotation of drive shaft 22. Therefore, since the main shaft 12 must be driven in such a manner that the main shaft 12 rotates once in one half cycle of the rotation of the drive shaft 22, the target rotation amount is twice the rotation amount of the drive shaft.

The rotation amount calculator 35 is configured to generate a rotation command signal Rc for controlling the spindle motor 13 in the spindle control device 14 and to rotationally drive the spindle 12 by the target rotation amount, based on the obtained target rotation amount, and to output the rotation command signal Rc to the spindle control device 14.

The synchronization control device 3 in the present embodiment is configured to correct the rotation amount of the main shaft 12 based on the deviation between the opening side detection signal Rd and the main shaft side detection signal Rm.

Specifically, the rotation amount calculator 35 is configured as described above, and the spindle control device 14 drives the spindle motor 13 in accordance with the rotation command signal Rc, and as a result, the spindle 12 is rotationally driven following the rotation of the drive shaft 22 after the set time period (0.5msec) in the one rotation period (one weaving cycle). Therefore, when the time point at which the rotation angle of the spindle 12 reaches a predetermined rotation angle (referred to as a "set angle" in the present invention, hereinafter referred to as a "set angle") set in advance in one rotation of the spindle 12 and the time point at which the drive shaft 22 reaches the rotation angle of the drive shaft 22 corresponding to the set angle (hereinafter referred to as a "reference angle") are compared, the time point at which the spindle 12 reaches the set angle should be after the set time period (0.5msec) with respect to the time point at which the drive shaft 22 reaches the reference angle. However, in some cases, due to some cause (e.g., abnormal vibration of the loom), the rotation amount may deviate between the drive shaft 22 and the main shaft 12, and the delay time between the time when the main shaft 12 reaches the set angle and the time when the drive shaft 22 reaches the reference angle may be longer or shorter than 0.5 msec.

Therefore, the synchronous control device 3 of the present embodiment is configured to correct the rotation amount of the main shaft 12 based on the opening side detection signal Rd of the opening side encoder 25 and the main shaft side detection signal Rm of the main shaft side encoder 15. The synchronization control device 3 includes, as its constituent elements, a discriminator 32, an angle detector 33, a comparator 34, and a corrector 36 included in the arithmetic unit 31.

In the present embodiment, the set angle of the spindle 12 is set to 0 ° (360 °), and the reference angle of the drive shaft 22 corresponding to the set angle is set to 180 °, 360 ° (0 °).

The discriminator 32 is connected to the opening-side encoder 25 on its input side, and is connected to the angle detector 33 on its output side. The discriminator 32 is configured to determine the rotation angle of the drive shaft 22 based on the opening-side detection signal Rd output from the opening-side encoder 25. In addition, the discriminator 32 is configured to discriminate that the obtained rotation angle of the drive shaft 22 has reached the reference angle (180 °, 360 ° (0 °)), and to output a signal (hereinafter referred to as "reference signal T0") indicating a timing at which the crank angle should reach the set angle (0 °) to the angle detector 33 after 0.5msec from the time point at which the discriminator has reached the reference angle (after the set time period).

The angle detector 33 is connected to the spindle-side encoder 15 and the discriminator 32 on its input side, and to the comparator 34 on its output side. The angle detector 33 is configured to be able to determine the crank angle based on the spindle-side detection signal Rm output from the spindle-side encoder 15. In addition, the angle detector 33 is configured to determine the crank angle at the time when the reference signal T0 is output from the discriminator 32. The angle detector 33 is configured to output a signal indicating the obtained crank angle (hereinafter referred to as "angle signal θ") to the comparator 34.

The comparator 34 is connected on its input side to the angle detector 33 and on its output side to the corrector 36 in the arithmetic unit 31, and the comparator 34 is configured such that, when the angle signal θ is output from the angle detector 33, a deviation of the crank angle from the set angle is found by comparing the crank angle indicated by the angle signal θ with the set angle (0 °) that is the rotation angle at which the crank angle is reached at the time point of outputting the reference signal T0, and a deviation signal △ θ indicating the found deviation is output to the arithmetic unit 31, but the deviation referred to herein also includes 0, that is, when the deviation is 0, the comparator 34 outputs a deviation signal △ θ corresponding to the deviation being equal to 0 to the arithmetic unit 31.

The corrector 36 of the computing unit 31 is connected to the comparator 34 on its input side and to the rotation amount computing unit 35 on its output side, and the corrector 36 is configured such that, when the deviation signal △ θ from the comparator 34 is input, a correction rotation amount for correcting the target rotation amount of the main shaft 12 obtained by the rotation amount computing unit 35 is obtained as described above based on the deviation indicated by the deviation signal △ θ.

More specifically, the corrector 36 is configured to store the deviation indicated by the deviation signal △ θ every time the deviation signal △ θ is input from the comparator 34, and to calculate an average value of the deviations of the set number of times (hereinafter also referred to as "deviation average value") when the number of times the deviation signal △ θ is input reaches a predetermined number of times (for example, 10 times (10 weaving cycles), hereinafter referred to as "set number of times").

As described above, the corrector 36 is configured to calculate the correction rotation amount based on the deviation average value every time the deviation average value is calculated. Specifically, in the present embodiment, a plurality of correction rotation amounts corresponding to a plurality of assumed deviations are set in advance in the corrector 36 so as to correspond to the magnitudes of the deviations, and the corrector 36 selects a correction rotation amount corresponding to the magnitude of the deviation average value obtained as described above. Incidentally, regarding the correction rotation amount, when the deviation average value is larger than 0, since the rotation of the main shaft 12 is in a retarded state with respect to the rotation of the drive shaft 22, the value of the target rotation amount is increased, that is, it is assumed that the rotation amount of which the correction rotation amount is larger than 0 is set. On the other hand, when the deviation average value is less than 0, since the rotation of the main shaft 12 is in an advanced state with respect to the rotation of the drive shaft 22, the value of the target rotation amount is reduced, that is, a rotation amount assuming that the correction rotation amount is set to be less than 0. However, when the deviation average value is equal to 0, the value of the target rotation amount is not increased or decreased, that is, it is assumed that the correction rotation amount is set equal to 0. In addition, as described above, the corrector 36 is configured to output the correction signal C corresponding to the obtained corrected rotation amount to the rotation amount calculator 35 every time the corrected rotation amount is obtained (every time the deviation average value is calculated).

The rotation amount calculator 35 is configured to correct the target rotation amount of the main shaft 12 obtained at the time point when the correction signal C is output from the corrector 36, based on the corrected rotation amount indicated by the correction signal C, that is, the rotation amount calculator 35 is configured to output the rotation command signal Rc output at the time point when the corrected rotation amount is obtained by the corrector 36 or when the deviation average value is obtained as described above at the time point when the deviation signal △ θ of the set number of times is output from the comparator 34, as the rotation command signal corresponding to the rotation amount obtained by adding the corrected rotation amount corresponding to the deviation average value to the target rotation amount.

Therefore, when the deviation average value is larger than 0, that is, when the rotation of the main shaft 12 is delayed with respect to the rotation of the drive shaft 22, the corrected rotation amount is larger than 0, and therefore the rotation amount calculator 35 outputs the rotation command signal Rc corresponding to a new target rotation amount obtained by increasing the target rotation amount (rotation amount twice as large as the rotation amount of the drive shaft). When the deviation average value is smaller than 0, that is, when the rotation of the main shaft 12 is advanced with respect to the rotation of the drive shaft 22, the corrected rotation amount is smaller than 0, and therefore the rotation amount calculator 35 outputs the rotation command signal Rc corresponding to a new target rotation amount obtained by reducing the target rotation amount. When the average deviation value is equal to 0, that is, when there is no deviation in the rotation amount between the drive shaft 22 and the main shaft 12, the corrected rotation amount is equal to 0, and therefore the rotation amount calculator 35 outputs the rotation command signal Rc corresponding to the target rotation amount.

In the present embodiment, the synchronization control device 3 may be a device including a circuit in which each component of the circuit is constituted by a circuit element having a function, or a computer programmed for the function of each component may operate as the synchronization control device 3. The synchronization control device 3, the spindle control device 14, the shedding control device 24, and the input setting device 16 may be independent devices (including a computer operating as a device), and one computer may operate as a plurality of devices.

The loom provided with the synchronization control device 3 in the present embodiment described above functions as described in the following (1) to (8).

(1) When an operation button (not shown) is operated at the start of operation of the loom, the drive of the shedding motor 23 by the shedding control device 24 in the shedding device 2 of the jacquard is started. At the same time, the rotation of the drive shaft 22 is started. The shedding motor 23 is driven to rotate the drive shaft 22 at a rotation speed of one-half of a set rotation speed set in advance as weaving conditions.

(2) When the rotation of the drive shaft 22 is started, the opening-side encoder 25 detects the rotation amount thereof, and at the same time, the opening-side detection signal Rd corresponding to the rotation amount is output from the opening-side encoder 25 to the synchronization control device 3.

(3) In addition, as described above, in the synchronous control device 3, the drive shaft rotation amount in the previous set period is obtained in the rotation amount arithmetic unit 35 in the arithmetic unit 31 based on the opening side detection signal Rd from the opening side encoder 25 every set period (0.5msec) after the start of rotation of the drive shaft 22.

(4) In addition, each time the arithmetic unit 31 (rotation amount arithmetic unit 35) in the synchronous control device 3 obtains the drive shaft rotation amount in this manner (that is, in each of the above-described setting time periods), the target rotation amount of the main shaft 12 is obtained as described above based on the obtained drive shaft rotation amount. When the target rotation amount of the spindle 12 is obtained in this manner, the rotation command signal Rc corresponding to the target rotation amount is output from the rotation amount calculator 35 to the spindle control device 14 in the weaving device 1.

(5) Then, in accordance with the output of the rotation command signal Rc, the spindle control device 14 controls the driving of the spindle motor 13 so that the spindle 12 rotates by the target rotation amount indicated by the rotation command signal Rc for the set time period from the time point. As a result, in the loom, the rotation of the main shaft 12 with respect to the drive shaft 22 is rotationally driven following it with a delay of the above-described set period (0.5 msec). That is, the loom is in a state where the main shaft 12 is driven to rotate synchronously with the rotation of the drive shaft 22.

(6) In this way, according to the loom described above, the drive shaft 22 of the jacquard shedding device 2 is rotationally driven based on the set rotation speed, and the main shaft 12 of the weaving device 1 is rotationally driven in synchronization with (follows) the rotation of the drive shaft 22, so that compared with the existing loom in which the drive shaft 22 is rotationally driven in synchronization with the rotation of the main shaft 12, an inexpensive induction motor can be used as the shedding motor 23 instead of the existing expensive synchronous motor. In addition, the spindle motor 13 may be an inexpensive synchronous motor having a small output power in consideration of the load acting on the spindle 12, and thus the cost of the entire loom may be reduced.

(7) In addition, as described above, the drive of the spindle motor 13 is controlled so that the spindle 12 is rotationally driven in synchronization with the rotation of the drive shaft 22, and in addition, in the loom of the present embodiment, the target rotational amount of the spindle 12 is controlled to be corrected at a predetermined point in time as necessary to maintain a state in which the rotation of the spindle 13 is more accurately synchronized with the rotation of the drive shaft 22. Details are as follows.

In the loom of the present embodiment, at the time point when the crank angle is assumed to reach the set angle (360 ° (0 °), that is, at the time point when the set time period (0.5msec) has elapsed from the time point when the rotation angle of the drive shaft 22 reaches the reference angle, the reference signal T0 is output from the discriminator 32 to the angle detector 33 in the synchronization control device 3.

At the same time, the angle detector 33 calculates a crank angle (actual crank angle) at that time based on the main shaft side detection signal Rm output from the main shaft side encoder 15, and outputs an angle signal θ corresponding to the calculated actual crank angle to the comparator 34.

The comparator 34 compares the obtained actual crank angle with the set angle (0 °) assumed to reach the crank angle at the time point when the reference signal T0 is output, thereby obtaining a deviation, and the comparator 34 outputs a deviation signal △ θ corresponding to the obtained deviation to the corrector 36 in the arithmetic unit 31.

As described above, the corrector 36 obtains the deviation average value from the deviation signal △ θ of the set number of times, and outputs the correction signal C corresponding to the corrected rotation amount obtained based on the deviation average value to the rotation amount calculator 35 in the calculator 31.

The target rotation amount of the spindle 12 is corrected by the rotation amount calculator 35 based on the corrected rotation amount, the target rotation amount of the spindle 12 obtained at the time point when the average deviation value is calculated (the time point when the deviation signal △ θ of the set number of times is output from the comparator 34) is corrected, and the rotation command signal Rc corresponding to the corrected target rotation amount of the spindle 12 is output from the rotation amount calculator 35 to the spindle control device 14, and the spindle motor 13 is driven by the spindle control device 14 based on the corrected target rotation amount of the spindle 12.

(8) Therefore, as described above, according to the loom of the present invention, even in the case where the rotation amount between the drive shaft 22 and the main shaft 12 is in a state of being deviated due to some reason, since the correction control of correcting the rotation amount of the main shaft 12 is performed by the synchronization control device 3 at a predetermined point of time to eliminate the deviation, it is possible to maintain the state in which the rotation of the main shaft 12 and the rotation of the drive shaft 22 are more accurately synchronized.

The present invention is not limited to the above-described examples (the above-described examples), but can be implemented in modified embodiments such as the following (1) to (9).

(1) In the above-described embodiment, the state of the jacquard shedding device corresponding to the state in which the crank angle of the weaving device (loom main body) is 0 ° is set to the state in which the rotation angle of the drive shaft is 0 ° (360 °) or 180 °, and on the premise that the weaving is performed, the drive control of the spindle motor is performed based on the rotation amount of the drive shaft.

The above premise is based on weaving under weaving conditions in which the healds are driven so that the shedding device of the jacquard is in the closed state when the rotation angle of the drive shaft is equal to 0 ° (360 °) or 180 °, and the warp yarn is in the closed state at the beating-up time point at which the crank angle is equal to 0 °. However, in weaving by a loom (not limited to the loom of the present invention), weaving is not limited to the case where the crank angle at the beating-up time (beating-up angle), that is, the crank angle equal to 0 °, coincides with the crossing timing at which the warp yarn is in the closed state, and depending on weaving conditions, the crossing timing may be set at a time point when the crank angle reaches, for example, 300 ° before the crank angle reaches 0 ° to perform weaving.

In addition, the present invention is applicable not only to the case where the weaving is performed by making both the weft angles and the crossing times the same as in the above-described embodiment, but also to the case where the weaving is performed by making both the weft angles and the crossing times different from each other as described above. Specifically, as described above, in the case where the jacquard shedding device is configured such that the warp yarn is in the closed state when the rotation angle of the drive shaft is 0 ° (360 °) or 180 °, for example, in the case where weaving is performed such that the warp yarn is in the closed state by the jacquard shedding device when the crank angle in the loom main body is 300 °, the drive control of the spindle motor is performed such that the crank angle reaches 300 ° after a predetermined period of time (after 0.5msec in the above-described embodiment) has elapsed from the time point when the rotation angle of the drive shaft reaches 0 ° (360 °) or 180 °.

(2) In the above embodiment, the target rotation amount of the main shaft is corrected based on the deviation (deviation average) obtained as a result of the comparison between the actual rotation angle of the crank angle obtained based on the reference angle of the drive shaft corresponding to the set angle and the set angle, for the set angle determined during one rotation of the main shaft. In addition, in the above embodiment, the set angle is set to 0 °.

However, in the present invention, the set angle is not limited to 0 °, and may be a rotation angle other than 0 °. However, since the weft insertion may be affected if the target rotation amount of the main shaft is corrected during the weft insertion operation, the set angle is preferably set to a rotation angle at which the weft insertion operation is not performed (a rotation angle in a period from the end of the weft insertion operation to the start of the next weft insertion operation).

In addition, when the set angle is set to a rotation angle other than 0 °, the reference angle of the drive shaft naturally corresponds to the set angle other than 0 °. Specifically, when the set angle is set to 20 °, in a loom that performs weaving by matching the crossing time and the beat-up angle as in the above-described embodiment, the reference angles are 10 ° (20 °/2) and 190 ° (20 °/2+180 °).

In the loom that performs weaving by making the crossing timing different from the beating-up angle (by providing an angular difference between the crossing timing and the beating-up angle) as in the above-described example, the reference angle corresponds to the angular difference. Specifically, for example, in a loom in which a crank angle corresponding to a rotation angle of a drive shaft of 0 ° is set to 300 °, since the rotation of the drive shaft is advanced by 30 ° (the crank angle is 60 °) from the rotation of the main shaft, when the set angle is 20 °, the reference angles are 40 ° (10 ° +30 °) and 220 ° (190 ° +30 °).

(3) In the above-described embodiment, as described above, the correction of the target rotation amount of the spindle (hereinafter, simply referred to as "correction") is performed at the time point when the deviation of the above-described set number of times is obtained in advance. In addition, in the above embodiment, the set number of times is set to 10 times.

However, in the present invention, the set number of times is not limited to 10 times, and may be a number of times other than 10 times (for example, 30 times). As described above, the number of times of setting in the present invention is not limited to a plurality of times, and may be 1 time. In this case, the correction is performed every time the deviation is obtained, that is, every time the spindle rotates once. Even when the set number of times is set to a plurality of times, as in the above-described embodiment, the correction may be performed not only based on the average value of the deviations but also based on the (one) deviation obtained at the set number of times.

(4) In the above embodiment, regarding the calculation of the deviation average value, the deviation is obtained every time the main shaft rotates, and the deviation average value is calculated based on the deviation of the set number of times at the time point when the deviation of the set number of times is obtained.

However, in the present invention, the calculation method is not limited to this, and the deviation average value may be calculated from the actual average value of the crank angles of the set number of times and the set value of the set angle. In this case, the angle detector in the synchronization control device may have a function of averaging the values. Specifically, the angle detector may store an actual crank angle obtained for each rotation of the spindle, and when the set number of times is reached, the angle detector may obtain an average value based on the stored actual crank angle for the set number of times and output the average value to the comparator. In addition, the comparator may calculate the deviation (deviation average value) based on the actual average value of the crank angles output from the angle detector and the set value of the set angle.

(5) In the above embodiment, the control related to the correction is performed in such a manner that the correction is completed through three processes: a process of determining a deviation based on the set angle and the actual crank angle (first process), a process of determining a corrected rotation amount based on the deviation (second process), and a process of correcting the target rotation amount using the determined corrected rotation amount (third process). On this basis, in the above-described embodiment, these three processes are performed continuously (control at the same point in time). Specifically, the first process, the second process, and the third process are performed at a time point when the reference signal is output, that is, at a time point when the crank angle reaches the set angle (a time point when the set time period has elapsed from a time point when the rotation angle of the drive shaft reaches the reference angle) (although the three processes are sequentially performed, the time required for the three processes is very short compared to the set time period.

However, in the present invention, these three processes are not necessarily performed at the same time point, but may be performed at different time points. For example, the first process and the second process may be performed at a time point when the reference signal is output, and the third process may be performed at a time point when the set time period has elapsed n times (n ≧ 1) after the reference signal is output. Further, as described above, the target rotation amount is obtained every time the set time zone elapses, and therefore the target rotation amount to be corrected is the target rotation amount obtained at the time point when the third process is performed. Alternatively, the second process and the third process may be performed at the same time point, instead of performing the first process and the second process at the same time point.

(6) In the above embodiment, the correction is performed based on the correction rotation amount corresponding to the obtained deviation (deviation average).

However, in the present invention, the corrected rotation amount in the correction is not limited to the value corresponding to the deviation obtained as in the above-described embodiment, and may be a fixed value (fixed rotation amount) set in advance. In this case, as a result of the deviation (deviation average value) obtained by the comparator, whether the deviation is a positive deviation or a negative deviation is determined, and at the same time, a deviation signal corresponding to the sign of the deviation is output from the comparator to the arithmetic unit (corrector). The correction is performed by adding or subtracting a correction rotation amount, which is a positive fixed value preset for the target rotation amount based on the sign of the deviation indicated by the deviation signal. Specifically, when the deviation signal output from the comparator indicates a positive deviation, that is, when the rotation of the main shaft is in a retarded state with respect to the rotation of the drive shaft, the correction is performed by adding the target rotation amount to the fixed rotation amount, and when the deviation signal indicates a negative deviation, that is, when the rotation of the main shaft is in an advanced state with respect to the rotation of the drive shaft, the correction is performed by subtracting the fixed rotation amount from the target rotation amount.

(7) In the above-described example, the synchronization control means is configured in such a manner that the deviation (deviation) of the rotation amount between the main shaft and the drive shaft is eliminated by the above-described correction. That is, the synchronization control device is configured to have such a correction function.

However, in the present invention, the synchronization control device is not limited to the configuration having such a correction function, and may be configured to have a function of outputting an alarm signal to the loom main body in accordance with the occurrence of the deviation. In this case, when a slight deviation in the rotation amount is allowed, the synchronization control device may be configured to output the alarm signal when the deviation exceeds a preset allowable value. In addition, the loom main body may be configured such that when the alarm signal is output from the synchronization control device, information indicating that synchronization is lost between the shedding device and the weaving device is displayed on a display device such as the input setting device in the above-described embodiment. The loom main body may be configured to perform a stop operation in addition to (or instead of) the display of the message in response to the output of the warning signal.

(8) As described above, in the present invention, the spindle motor controls the driving of the spindle in such a manner that the spindle rotates following the drive shaft.

Incidentally, jacquard shedding devices are commonly used for the weaving of complex patterns of textiles. The shedding pattern is set to be one repetition of a plurality of weaving cycles, and weaving is performed by repeating driving of the healds according to the shedding pattern. In the case of weaving the above-described complex pattern textile, the shedding pattern may be set so that the number of warp yarns located above and the number of warp yarns located below in each weaving cycle in one repeat of the shedding pattern are greatly different from each other in each weaving cycle.

In addition, in the shedding device of the jacquard, each heddle is mechanically biased to one side (usually, the lower side) in the up-down direction and is displaced in the other direction by the jacquard main body (drive mechanism). Therefore, as described above, although a load acts on the drive shaft when the healds are displaced, the magnitude of the load is proportional to the number of the healds displaced in the other direction.

However, according to the present invention, as described above, although an inexpensive induction motor can be employed as the opening motor, in this case, the rotation of the drive shaft may be affected by the magnitude of the load acting on the drive shaft.

The influence on the rotation of the drive shaft is naturally greater as the load increases, and the rotation speed may vary depending on the magnitude of the load. However, as described above, the magnitude of the load is proportional to the number of heddles displaced toward the other side, but the number of heddles displaced toward the other side is determined by the relationship between the vertical position of each warp yarn at the time of maximum shedding in each weaving cycle set in the shedding pattern and the vertical position of each warp yarn at the time of maximum shedding in the next weaving cycle of each manufacturing cycle. The warp yarn set at the one position at the time of the maximum shedding in each manufacturing cycle and the warp yarn set at the other position at the time of the maximum shedding in the next weaving cycle start to be displaced toward the other side in the vicinity of the middle in the next weaving cycle.

Therefore, as described above, when the shedding pattern is set so that the number of warp yarns positioned above and the number of warp yarns positioned below in each weaving cycle are greatly different from each other in each weaving cycle, the rotation speed of the drive shaft may change in the vicinity of the middle of one or more specific weaving cycles in which the shedding pattern is repeated. In this case, when the drive control of the spindle motor is performed such that the rotation of the spindle follows the rotation of the drive shaft as described above, the drive control is performed such that the rotation speed of the spindle motor is abruptly changed in the vicinity of the middle of the weaving cycle, and as a result, the load applied to the spindle motor increases.

In addition, it is possible to grasp from the opening pattern whether or not the rotation speed has changed in the vicinity of the middle of the weaving cycle in this manner, according to the weaving conditions at this time. Therefore, if it is known in advance that such a change in the rotation speed has occurred, it is considered that a control parameter (for example, a control gain is lowered) used for driving control of the spindle motor in the spindle control device is changed. In this way, the fluctuation in rotation of the spindle motor can be suppressed by reducing the following performance of the spindle motor, and as a result, the load imposed on the spindle motor can be suppressed.

However, in this case, since the following performance of the spindle motor is lowered even in a weaving cycle in which the rotation speed of the drive shaft is not changed, the synchronization between the drive shaft and the spindle is deviated, and the weft insertion may be affected in the weaving cycle.

Therefore, in the present invention, the synchronous control device may be configured to change the control parameter for controlling the spindle motor in accordance with the magnitude of the load acting on the drive shaft, specifically, configured to change the control parameter in each weaving cycle in one repetition of the shedding pattern based on the shedding pattern. The synchronous control device further includes a parameter changer as a component thereof. This structure is described in detail based on fig. 3 below. In fig. 3, the same components as those in the above embodiment are denoted by the same reference numerals.

First, as a premise, the spindle control device 14 is configured to change a control parameter for driving control of the spindle motor 13 in accordance with an output from the synchronization control device 3. In addition, here, the control parameter is a control gain. Incidentally, this control gain is a control parameter for changing the following property of the spindle motor 13, and by reducing this value, the following property of the spindle motor 13 can be reduced.

In addition, in general, the opening pattern stored in the opening control device 24 is set in such a manner that it includes weaving steps in one repetition of the opening pattern (one weaving step is equivalent to one weaving cycle). Therefore, the shedding control device 24 is configured to grasp the current weaving step based on the opening side detection signal Rd from the opening side encoder 25, and to output a step signal S indicating the step number at the time point when the weaving step is updated.

As shown in fig. 3, the synchronization control device 3 includes a parameter changer 37 in addition to the configuration of the above embodiment. The parameter changer 37 is connected to the opening control device 24 and the input setting device 16 of the weaving device 1 on its input side, and is connected to the spindle control device 14 on its output side. In addition, the parameter changer 37 sets (stores) a control gain having a plurality of values in advance so as to correspond to each weaving cycle (weaving step) in which the opening pattern repeats.

Specifically, the control gain is determined as a reference control gain that is considered appropriate for control in which the rotation speed of the drive shaft 22 (or the spindle motor 13 that controls the drive of the spindle 12 so as to follow the rotation of the drive shaft 22) does not change due to the load. On this basis, for the weaving step (weaving cycle) in which the rotation speed of the drive shaft 22 is expected to change, based on the opening pattern, a control gain lower than the value of the above-described reference control gain is set in a manner corresponding to the step number thereof. On the other hand, for the other weaving steps, the reference control gain is set so as to correspond to the step number. Incidentally, the control gain is input-set by the input-setting device 16. The control gain input to be set is transmitted to the parameter changer 37 and stored in the parameter changer 37.

When the step signal S is output from the opening control device 24, the parameter changer 37 is configured to select a value of the control gain corresponding to the step number indicated by the step signal S and output a gain signal G indicating the selected value to the spindle control device 14.

In the spindle control device 14, when the gain signal G is output from the parameter changer 37, the value of the control gain used for the drive control of the spindle 12 is changed to a value corresponding to the control gain indicated by the gain signal G based on the gain signal G.

According to the synchronous control device 3 configured as described above, the drive control of the spindle motor 13 in each weaving cycle in which the opening pattern is repeated one by one is performed using the control gain corresponding to the weaving cycle (weaving step) set as described above. Accordingly, in the weaving cycle in which the load acting on the drive shaft 22 is large, since the followability of the spindle motor 13 is reduced, the rotation fluctuation of the spindle motor 13 is suppressed, and as a result, the load on the spindle motor 13 is reduced. In addition, in the weaving cycle in which the load acting on the drive shaft 22 is small, since the following performance of the spindle motor 13 is not lowered, the deviation of the synchronization of the drive shaft 22 and the spindle 12 can be prevented.

In addition, although the control parameter is the control gain in the above, the control parameter is not limited to the control gain, and may be other control parameters such as a time constant associated with the responsiveness of the spindle motor 13.

In the above, the control parameter is changed by a method selected from a plurality of preset values of the control gain. However, the method for changing the control parameter is not limited to such a method. For example, the control parameter may be changed by a method of calculating a control gain based on the magnitude of the load acting on the drive shaft 22. In this case, too, the magnitude of the load acting on the drive shaft 22 may be calculated based on the shedding pattern (specifically, the number of heddles displaced per weaving cycle).

(9) In the above, an example in which the present invention is applied to a loom provided with a jacquard shedding device as the shedding device is described. However, with regard to the loom to which the present invention is applied, the shedding device is not limited to the jacquard shedding device described above, but may be a dobby shedding device of a so-called rotary drive type in which the heald frame is displaced in the up-down direction by a single drive shaft, and the drive shaft of the dobby shedding device is rotationally driven by a shedding motor independent of the main shaft motor of the loom. That is, the present invention is also applicable to a loom provided with such a dobby shedding device.

The present invention is not limited to the above-described embodiments, and can be modified as appropriate without departing from the scope of the invention.

Claims

1. A synchronous control method of a loom provided with a shedding device having a shedding motor independent of a spindle motor of the loom as a drive source and displacing each heddle in a vertical direction by driving a single drive shaft common to all heddles by the shedding motor, characterized in that,

at least when the loom is in steady operation, the rotation amount of the drive shaft in each loom cycle is detected, and the drive of the spindle motor is controlled so that the spindle of the loom rotates synchronously with respect to the drive shaft in accordance with a detection signal corresponding to the rotation amount.

2. The synchronous control method of a loom according to claim 1,

the drive control of the spindle motor includes:

rotating the main shaft by a target rotation amount found based on the rotation amount of the drive shaft detected at each preset set period of time within the set period of time from a time point at which the target rotation amount is found,

detecting an actual rotation angle of the main shaft at a time point when it is assumed that the rotation angle of the main shaft reaches a set angle, wherein the set angle is a predetermined rotation angle of the main shaft set in advance,

comparing the detected actual rotation angle with the set angle to find a deviation of the actual rotation angle from the set angle,

at a time point when the deviation is obtained a predetermined number of times, the target rotation amount obtained for the set time period after the time point is corrected based on the deviation.

3. The synchronous control method of a loom according to claim 1 or 2,

a control parameter for controlling the spindle motor is changed according to a load acting on the drive shaft along with the displacement of the heald.

4. A loom is provided with a shedding device which has a shedding motor independent of a spindle motor of the loom as a drive source and displaces each heddle in the vertical direction by driving a single drive shaft common to all heddles by the shedding motor, and a spindle control device which controls the drive of the spindle motor,

the loom is characterized by comprising:

a rotation detecting device that detects a rotation amount of the drive shaft in each loom cycle at least when the loom is stably operated; and

and a synchronization control device that obtains a rotation amount of a main shaft of a loom so that the main shaft is synchronized with the drive shaft in accordance with a detection signal output from the rotation detection device, and outputs a rotation command signal based on the obtained rotation amount of the main shaft to the main shaft control device.

5. The weaving machine according to claim 4,

the synchronization control device includes:

an arithmetic unit that obtains a target rotation amount of the spindle rotation in the set time period from a time point at which the target rotation amount is obtained based on the rotation amount of the drive shaft detected for each set time period set in advance;

an angle detector that obtains an actual rotation angle of the main shaft at a time point when it is assumed that the rotation angle of the main shaft reaches a set angle, the set angle being a predetermined rotation angle of the main shaft set in advance; and

a comparator that compares the actual rotation angle obtained by the angle detector with the set angle and obtains a deviation of the actual rotation angle from the set angle,

the arithmetic unit includes a corrector that corrects the target rotation amount obtained for the set time period after a time point at which the deviation is obtained a predetermined number of times, based on the deviation.

6. Weaving machine according to claim 4 or 5,

the synchronization control device has a function of changing a control parameter used for controlling the spindle motor in accordance with a load acting on the drive shaft in accordance with a displacement of the heald.