EP1637636B1

EP1637636B1 - Set point deciding apparatus

Info

Publication number: EP1637636B1
Application number: EP05018426A
Authority: EP
Inventors: Koki Yamazaki; Hideyuki Kontani
Original assignee: Tsudakoma Industrial Co Ltd
Current assignee: Tsudakoma Corp
Priority date: 2004-09-17
Filing date: 2005-08-24
Publication date: 2011-11-23
Anticipated expiration: 2025-08-24
Also published as: KR20060051049A; CN1749457A; CN1749457B; EP1637636A2; JP2006083502A; JP4339217B2; EP1637636A3

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a technique for deciding a set point of an operation mode of an apparatus for a weft bar preventing apparatus of a loom, based on information on a cloth.

Description of Prior Art

As one of weft bar preventing apparatus of a loom, there is known an apparatus which performs so-called kick-back operation by rotating or reversing a warp beam or a take-up roller by a certain rotation angle prior to starting the loom for displacing a cloth fell to a predetermined position (see, e.g., Japanese Patent Appln. Public Disclosure No. 61-63750 Official Gazette).
Also, as a weft bar preventing apparatus of a multicolor weft inserting loom, there is known an apparatus which performs so-called kick-back operation by presetting an amount of correction to correct the position of a cloth fell for each color pattern of the weft and, when restarting the loom, displaces the cloth fell to a predetermined position by rotating or reversing a warp beam or a take-up roller according to the amount of correction corresponding to the weft color pattern (see, e.g., Japanese Patent Appln. Public Disclosure No. 3-27154 Official Gazette).
However, operation modes of these weft bar preventing apparatus are set, based on an operator's experience and made while judging whether or not a weft bar is generated in an actual cloth, so that it takes a long time for an operator with little experience to find out an optimum value.
Since a method of setting a weft bar preventing apparatus based on an operator's experience takes much time for an operator to adjust setting of the weft bar preventing apparatus, a production efficiency for producing a quality cloth tends to be low. And further, such setting varies according to cloth. Therefore, such inconvenience is experienced whenever a new kind of cloth not yet made is woven.

SUMMARY OF THE INVENTION

An object of the present invention lies in shortening the time required for adjusting a loom, by providing information suitable for the specification of a cloth for setting an operation mode of a weft bar preventing apparatus.
The set point deciding apparatus according to the present invention comprises an input device into which information on a cloth is inputted, and an output device which decides and outputs a set point of an operation mode of a weft bar preventing apparatus of a loom. The information to be inputted on a cloth further includes either a cover factor showing a crowding state of the yarns of the cloth, or a value on which the cover factor is based. The output device includes a database in which set points on a plurality of operation modes in the weft bar preventing action are pre-stored in correspondence to the information on the cloth, and search means for searching a set point of the corresponding operation mode from the database. The output device, based on the cover factor obtained as the information on the cloth, decides a set point of the operation mode corresponding thereto as the set point of the operation mode of the weft bar preventing apparatus.
Here, when the cover factor showing the crowding state of yarns is indicated as CF, the cover factor CF is shown by: cover factor CF = warp cover factor CFw + weft cover factor CFp. However, the warp cover factor CFw = A *2.54/√B, and the weft cover factor CFp = C/√D. Parameter A shows the number of warp yarns per unit cloth width dimension, parameter B shows the thickness of a warp yarn (yarn number count), parameter C the set beating density, and parameter D shows the thickness of a weft yarn (yarn number count).
Concretely, parameter A is obtained by dividing the total number of warp yarns by reed drawing-in width. Consequently, parameter A is calculated on the basis of the total number of the warp yarns and the reed drawing-in width.
According to the present invention, a cover factor showing a crowding state of yarns of a cloth or a value which is the basis of the cover factor is inputted into the input device, the output device which searches the corresponding set point of the operation mode from the database decides and outputs the searched value as the set point of the operation mode of the weft bar preventing apparatus. Consequently, even in case a specification of a cloth is changed due to a change in kind of a cloth, if an operator inputs the cover factor or the value as the basis of the cover factor into the input device, the output device can automatically output a set point of the operation mode of the weft bar preventing apparatus to which at least the cover factor is reflected, thereby enabling to set the value in the weft bar preventing apparatus.
Furthermore, the set point as output information which the set point deciding apparatus thus outputs is decided by reflecting the cover factor; therefore, it is a set point of an operation mode of the weft bar preventing apparatus in which difficulty in beating the weft is taken into account in comparison with the conventional one. Therefore, even an operator having a little experience can immediately produce a fine cloth without weft bar.
Since an operator does not have to repeat trials and errors as heretofore for a long period until finding out an optimum operation mode with difficulty in beating taken into account, thereby shortening the time taken for such adjustment.
The value on which the cover factor is based as the information on the cloth includes the number of warp yarns per unit weaving width, the thickness of the warp yarn, weft beating density, and a value concerning the thickness of the weft yarn. The output device may be adapted to calculate the cover factor on the basis of plural values on which the cover factor is based, and decide and output the set point at least on the basis of the calculated cover factor.
The information on the cloth may further include information on a kind of cloth or fabric texture, and the output device may include deciding and outputting the set point on the basis of at least one of the information on the kind or fabric texture, and on the basis of the cover factor.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic drawing of a loom having the set point deciding apparatus according to the present invention.
Fig. 2 is a block diagram showing the circumference of the weft bar preventing apparatus of the loom shown in Fig. 1.
Fig. 3 is a flow chart showing a series of processes from the time of inputting conditions of a weaving loom to the time of starting weaving operation by using the set point deciding apparatus of the present invention.
Fig. 4 is a view showing a screen at the time when the input information is inputted into the set point deciding apparatus according to the present invention.
Fig. 5 is a view showing a screen following Fig. 4.
Fig. 6 is a view of a screen following Fig. 5 and showing a kickback amount as one of the set points decided by the set point deciding apparatus according to the present invention.
Fig. 7 is a graph for explaining setting of a kickback amount corresponding to a time of stoppage concerning kickback operation as the weft bar preventing operation according to the present invention.

PREFERRED EMBODIMENT OF THE INVENTION

Referring to Fig. 1, in the loom 10, the warp yarns 12 are linked with a cloth fell 22 from a warp beam 14 around which the warp yarns 12 are wound through a back roller 16, a plurality of heald frames 18 and a reed 20.
The weft 24 inserted into a warp shedding is beaten by the reed 20 against the cloth fell 22 to become a cloth 26.
The cloth 26 reaches a take-up roller 28 from the cloth fell 22 through a guide roller 27. The cloth 26, reaching the take-up roller 28, is let off by the take-up roller 28 and a pair of press rollers 30 to a cloth beam 32. Such let off cloth 26 is taken up by the cloth beam 32.
The warp beam 14 is rotated by a let-off motor 34 through a gear mechanism (not shown) constituted by a decelerator like gears, so a plurality of warp yarns 12 are let off in a sheet form. The roll diameter of the warp yarns 12 wound round the warp beam 14 is detected as roll diameter D by a roll diameter detector 36.
Heald frames 18 are reciprocated vertically by a shedding drive portion 38 of a shedding device 37 to form the warp shed vertically. The shedding drive portion 38 converts the rotation of a main shaft 42 rotated by a main shaft motor 40 into reciprocation of heald frames 18.
The reed 20 is swung by the reed beating drive portion 44. The reed beating drive portion 44 converts the rotation of the main shaft 42 into swinging motion. So the reed 20 beats the weft 24 inserted into the shedding of the warp yarns 12 against the cloth fell 22.
The take-up roller 28 is rotated through a gear mechanism (not shown) constituted by a decelerator such as gears which receive the rotation of a take-up motor 46. The rotated take-up roller 28 lets off the cloth 26 to the cloth beam 32 in cooperation with the pair of press rollers 30.
The rotation angle of the main shaft 42 is detected by an encoder 48. The detected rotation angle of the main shaft 42 is fed as a main shaft rotation angle θ to a main controller 50 and a let-off controller 52 (see Fig. 2).
Referring to Fig. 2, the set point deciding device 54 has a touch panel 56 serving as an input device and an indicator. The set point deciding device 54 also has a database 58 in which set points T of a plurality of operation modes in a weft bar preventing operation are pre-stored in correspondence to the information on the cloth, and a memory 60 which stores a program for searching the set points T of plural operation modes in the weft bar preventing operation based on the database 58 and the inputted information on the cloth through the input device, and a central processing unit (CPU) 62 which serves as search means.
Also, the set point deciding apparatus 62 is connected to the touch panel 56, the database 58, the memory 60 and a port 64. When an operator inputs information on a cloth of the loom 10 through the touch panel 56, the CPU 62 reads out the program for searching the database 58 from the memory 60, and searches a set point from the database 58, based on the inputted information concerning the cloth.
The set point deciding apparatus 54 has not only a function to input the set point of the operation mode of a weft bar preventing apparatus 78 such as mentioned above but also a function as a setter of the loom 10 such as to input the set point for outputting a set point into a device (not shown) such as a warp tension controller as well as a weft insert device, and indicating the information of the loom 10.
The CPU 62 makes the touch panel 56 display the searched set point so that an operator can read. The CPU 62 may also make the touch panel 56 display the set point and output electric signals into a port 64. That is, the output device of the set point deciding apparatus 54 in this embodiment includes not only the touch panel 56 serving as an indicator, the database 58, the memory 60 and the CPU 62, but also the port 64.
The main controller 50 receives an operation signal S1, an inching signal S2, a reversing signal S3 and a stop signal S4 to be outputted from an operation button 66, an inching button 68, a reversing button 70, and a stop button 72, respectively. The main controller 50 receives a stop signal S5 to be outputted from a yarn breakage sensor (not shown) detecting that a warp yarn 12 or a weft yarn 24 is broken. The main controller 50 receives a plurality of set points T to be outputted from the set point deciding apparatus 54 so as to be used for controlling the loom 10.
The main controller 50 has a function to control driving of the let-off controller 52, a take-up controller 74, the shedding drive portion 38, and the main shaft drive portion 76, by the command signals S6 - S9 to be outputted. Also, the let-off controller 54, the take-up controller 74, the shedding drive portion 38 and the main shaft drive portion 76 constitute the drive circuit of the weft bar preventing apparatus 78 in this embodiment.
The let-off controller 52 controls the rotation of the output shaft of the let-off motor 34, based on the main shaft rotation angle θ, the set point T to be outputted from the set point deciding apparatus 54, the operation command signal S6 to be outputted from the main controller 50 and the roll diameter D.
In more detail, the let-off controller 52 controls the rotation of the output shaft of the let-off motor 34 so that, during the operation of the loom 10, a warp tension may maintain a target tension by the operation command signal S6 to be outputted from the main controller 50. Also, when the loom 10 stops, inches or reverses, or when the loom 10 starts operating, the let-off controller 52 controls the rotation of the output shaft of the let-off motor 34 so as to perform each weft bar preventing operation by generation of the command signal S6 for a fell control command, an inching or reversing command or a kickback command and the like. The let-off controller 52 receives set points such as a fell control amount at the time of fell control command, inching amount or reverse amount at the time of inching or reversing command, a kick back amount at the time of operation starting command directly from a setter as the set point deciding apparatus 54.
The take-up controller 74 controls a rotation amount of the output shaft of the take-up motor 46 on the basis of the main shaft rotation angle θ as well as the set point T and the operation command signal S6 to be outputted from the set point deciding apparatus 54.
In more detail, the take-up controller 74 controls the rotation of the output shaft of the take up motor 46 during operation of the loom 10, in synchronization with the rotation of the main shaft 42 of the loom 10 by the angle signal θ from the encoder 48 and the operation command signal S6 to be outputted from the main controller 50. The take-up controller 74 also controls the rotation of the output shaft of the take-up motor 46 at the time of stoppage of the loom 10, inching and reversing or at the time of starting operation of the loom 10, by generation of the command signal S6 for the fell control command, the inching and reversing commands or the kickback command and the like outputted from the main controller 50 so as to perform each weft bar preventing action. The take-up controller 74 receives set points such as an inching amount, a reversing amount, and a kickback amount at the time of these fell control command and the inching and reversing commands directly from a setter as the set point deciding apparatus 54.
For example, the shedding device 37 includes a leveling mechanism or the like which disengages the connection between the drive shaft of the shedding drive portion 38 and the main shaft 42 of the loom 10 and actuates an actuator of a hydraulic cylinder or the like, thereby bringing each heald frame 18 to a state of closed shed. The shedding drive portion 38 has its drive shaft connected with the main shaft 42 of the loom 10 while the loom is under operation, and vertically moves each heald frame 18 by the rotation of the main shaft. Also, when the loom 10 is stopped, the shedding drive portion 38 actuates the actuator so as to perform a weft bar preventing operation, which is a leveling action, based on the command signal S7 of a leveling command to be outputted from the main controller 50, and vertically moves each heald frame 18 to such a position as a warp shedding becomes a shed to be closed. In place of this, by constituting a leveling device with a clutch disposed between the drive shaft and the main shaft 40 as well as a motor which can be connected with the drive shaft through the clutch, and when the shedding drive portion 38 receives a leveling command, the clutch, in a state of being disengaged from the main shaft 40, rotates the drive shaft by the above-mentioned motor, thereby performing the leveling action.
The main shaft drive portion 76 controls the rotation of the output shaft of the main shaft motor 40, in turn, the main shaft 42, based on the command signal S8 to be outputted from the main controller 50 and the rotation torque signal S9.
In more detail, the main shaft drive portion 76 makes the shaft of the main shaft motor 40, in turn, the main shaft 42 turn at a high output torque for a certain period from the start of operation so as to perform a weft bar preventing operation on the basis of the operation command signal S8 to be outputted from the main controller 50, and the rotation torque signal S9 for a starting torque command and for a starting torque switching command, to make the reed 20 perform beating. The main shaft drive portion 76 makes the torque of the main shaft 42 reduced to a torque necessary for maintaining a steady operation from a predetermined timing onward when the rotation speed of the main shaft 40 reaches a steady rotation speed. The main shaft drive portion 76 thus performs a series of controls for driving.
The main shaft drive portion 76 also stops the rotation of the output shaft of the main shaft motor 40 at the stoppage of the loom 10 by turning off of the output of the operation command signal S1 to be outputted from the main controller 50. The main shaft drive portion 76, at the time of inching and reversing of the loom 10, rotates at a low speed the output shaft of the main shaft motor 40 in the rotating direction corresponding to the inching signal S2 or the reversing signal S3.
When textile goods in process woven by the loom are changed, an operator carries out looming work of the loom 10 and sets machine conditions corresponding to a new textile in the setter of the loom 10. At this time, the operator sets operation modes for weft bar preventing actions as a part of the work. Fig. 3 shows a series of processes from inputting the machine conditions till starting of the weaving operation.
Firstly, the operator operates the touch panel 56 as the input device of the set point deciding apparatus 54 and inputs the textile conditions for the cloth 26 (ST101). Examples of the screen 80 of the touch panel 56 are shown in Figs. 4 and 5.
In Fig. 4, a column indicating a plurality of items concerning the warp yarns 12 as information on the cloth as well as a column indicating the set points are respectively indicated in an area A on the left side of the screen 80 of the touch panel 56. Also, ten keys for inputting numerical values are indicated in an area B on the right side in Fig. 4. The illustration shows a state where the operator firstly touches the "reed drawing-in width" in the area A to have the screen 80 indicate the ten key, and is going to input a numerical value for "reed drawing-in width" by use of the indicated ten keys.
Fig. 5 shows a state that "190" is inputted as the value of the "reed drawing-in width" in Fig. 4. Also, in the area A on the left side showing information on the warp yarns 12 is shown a state that the information on the warp yarns 12 is shown, a state that "total number" is "10000" and "thickness" is yarn number count "40" respectively as the information of the warp yarns 12 which becomes the basis for calculating the cover factor and a state that "unit of thickness" is "cotton count" and "kind" is "cotton yarn" are selectively inputted.
Recent looms are given a function to detect a load acting on a back roll as a warp tension and control the amount of rotation of the warp beam 14 such that the detected warp tension maintains a tension set point. For this reason, it is possible to use, for example, the above-listed parameters as the information on the warp yarns 12 and to automatically decide the warp tension set point. More concretely, it can be calculated by the expression, tension set point S = unit tension K1 per 1 warp yarn × total number of warp yarns × correction factor K2, and the correction factor K2 can be calculated by selecting the below-mentioned kinds of textile, fabric texture, and cover factors.
The area C on the upper right side of Fig. 5 shows a state that the information of the weft 24 as the information on the cloth is inputted as the "thickness" to be the yarn number count "40" as well as a state that the "unit of thickness" and the "beating density" are respectively selected and inputted to be the "cotton count" and "50/inch."
The area D on the lower right side of Fig. 5 shows a state that the information on the texture or kind of the cloth as the information on the cloth is selectively inputted as the "fabric texture" to be "1/1 (plain weave)" and the "name of cloth" to be "spun in general." Such a series of processes on the indication and input in the touch panel 56 are performed such that the CPU 62 controls the touch panel 56 according to the program stored in the memory 60.
The operator, as shown in Fig. 5, inputs the information on the cloth as mentioned above by using the touch panel 56, and then presses a button B1 for "automatic setting for bar prevention" in the screen 80 (ST102).
In the touch panel 56, when the button for "automatic setting for bar prevention" is pressed, the CPU 62 calculates a cover factor representing a state of yarn crowing by using a below-mentioned formula on the basis of the input information heretofore inputted from the database 58, and searches a set point in each item of setting corresponding to the calculated cover factor (ST103).
The CPU 62, therefore, searches and decides set points of the set mode of the weft bar preventing action fit for the input information on the cloth and, as shown in Fig. 6, indicates the respective set points as decided in the screen 80 of the touch panel 56, and outputs the set point information into the main controller 50, let-off controller 52 and take-up controller 74 through the port 64 (ST104).
Fig. 6 shows an example where the operation mode of the automatically decided weft bar preventing action in the above-mentioned step ST104 is indicated in the screen 80, and examples of the set point amounts in the kickback operation to rotate the warp beam 14 or the take-up roller 28 prior to the start of operating the loom 10.
By pressing the "let-off' button or "take-up" button which are indicated keys in the screen 80, the amount of kickback corresponding to the pressed button is indicated in the area E. Fig. 6 shows the screen 80 of the touch panel 56 at the time when the "let off' button is pressed.
The "kickback mode" indicated in the screen 80 of the touch panel 56 shows that the "timing control" depending on a stoppage time is selected and that the stoppage time is selected and inputted to be "5" minutes. Also, by the operator's operation of the touch panel 56, a kickback mode to control at a uniform kickback amount regardless of the stoppage time can be selected.
The stoppage time herein shows, as shown in Fig. 7, a timing for switching the time control in the kickback operation, and in more particular, concerning the stoppage time control of the kickback amount, as shown in Fig. 7, for example, between the stoppage time "0" and the set time "5" a kickback reversal amount increased according to the increase of the stoppage time is generated by a function decided by the reversal amount 1, the reversal amount 2 and the stoppage time set point, while after a lapse of stoppage for 5 minutes, the kickback reversal amount of the reversal amount 2 is generated regardless of the stoppage time. However, such a setting as to increase the kickback reversal amount is increased stepwise for each stoppage time can be considered. The same applies to the kickback normal rotation amount.
The "normal rotation amount" and "reversal amount" indicated in the screen 80 of the touch panel 56 show a normal rotation amount and a reversal amount based on the weft picking in the kickback operation.
Regarding the kickback operation, there is further function such as setting a kickback amount independently in the setter for each cause of stoppage and selecting a kickback amount corresponding to the cause of stoppage generated during operation of the loom 10. In the illustration, the operator can set the set points at a weft stop time (such as generation of weft yarn blow-off), an APR time (actuation of automatic picking failure remover), and a warp stop independently.
After the operation mode of such weft bar preventing action is decided, the operator performs a trial weaving operation according to needs, and checks the effect of the weft bar preventing action based on the decided set point, that is, whether or not any weft bar is generated (ST105).
The operator, when judging as a result of the trial weaving that weft bars are generated, outputs the searched set point by operating the screen 80 of the touch panel 56 shown in Fig. 6 as a new set point T modified relative to the automatically decided set point into the let-off controller 52 or the take-up controller 74 which are the corresponding drive circuits.
The operator, after setting relative to the weft bar preventing apparatus 78 and setting or adjusting other machine conditions, presses the operation button 66 to start weaving operation of the loom 10 (ST106).
Table 1 shows an example of the database 58 for use in deciding operation modes of the weft bar preventing apparatus 78. Table 1 shows the operation modes of the weft bar preventing apparatus 78 according to the value of the cover factor relative to the information on a cloth.
To explain Table 1 in more detail, it shows an example where the cover factor is divided into four stages, and one or more operation modes of weft bar preventing actions are recorded for each of the four divisions of the cover factor. For example, even when the cover factors are different, the operation modes may be set to be the same, or may be set such that at least one of the plural operations are different as in case of the shedding leveling of the shedding drive portion 38 and the kickback operation of the take-up controller 74.

[Table 1]

Name of weft bar preventing action		Object device	Contents of setting	Set points
				Cover factor (CF value)
				to 14.9	15.0 to 29.9	30.0 to 39.9	40.0 or over
1	Fell control	Take-up device	Operation on/off	X	X	○	○
			Operation amount			a1	a2
		Let-off device	Operation	X	X	○	○
			Operation amount			b1	b2
2	Inching let-off	Take-up device	Operation amount	c1	c1	c1	c1
		Let-off device	Operation amount	d1	d1	d1	d1
3	Reverse return	Take-up device	Operation amount	c1'	c1'	c1'	c1'
		Let-off device	Operation amount	d1'	d1'	d1'	d1'
4	Shedding device leveling	Shedding device	Operation on/off	X	X	X	X
5	Kickback	Take-up device	Operation on/off	X	X	X	X
			With or without time control	X	X	X	X
			Operation amount 1 (normal rotation amount 1)	-	-	-	-
			Operation amount 2 (normal rotation amount 2)	-	-	-	-
			Operation amount 3 (normal rotation amount 1)	-	-	-	-
			Operation amount 4 (normal rotation amount 2)	-	-	-	-

		Let-off device	Operation on/off	○	○	○	○
			With or without time control	X	X	○	○
			Operation amount 1 (normal rotation amount 1)	e11	e11	e12	e13
			Operation amount 2 (normal rotation amount 2)	e11'	e11'	e12'	e13'
			Operation amount 3 (normal rotation amount 1)	e21	e21	e22	e23
			Operation amount 4 (normal rotation amount 2)	e21'	e21'	e22'	e23'

6	Start	Main shaft drive	Starting method	G1	G1	G2	G2
			Timing 1	-	-	h1	h1'
			Timing 2	-	-	h2	h2'
7	One thread insertion	Weft inserting apparatus	Operation on/off	X	X	○	○

8	Starting torque	Main shaft drive	Starting torque	j1	j1	j2	j2
			Switch timing	k1	k1	k1	k1
			Switch pick number	l1	l1	l2	l2

○ operation on X operation off
a1...shows specific value
G1 to G2 show kinds of starting method

Here, concerning the weft bar preventing action of the loom 1, operation modes corresponding to cover factors are illustrated, and the relation between items of operation modes of the database 58 and the cover factors are explained in the following.
Fell control
Fell control means an operation to rotate the warp beam 14 or the take-up roller 28 by a certain amount during inertial rotation of the main shaft 42 in case of stopping the loom 10 under operation and displace the position of the cloth fell 22 forward. This operation is effective in preventing generation of wavy set marks (note: corrugation marks, i.e., lateral stripes caused by leaving for a long time in a shedding state) by reducing the beating force from stopping the operation of the loom 10 till the loom 10 is started, and in preventing generation of any weft bar attributable to elongation of the warp which the loom 10 is stopped.
In the database 58, with or without operation, the amount of displacement (retreat) of the cloth fell 22, and the cover factor CF are systematically constituted for each device.
Inching let-off/reversing return
Inching let-off/reversing return means an operator's operation to rotate the warp beam 14 or the take-up roller 28 in the normal direction or in the reverse direction by a predetermined amount, after the loom 10 stopped, when an operator inches or reverses the loom 10 for reparation, for example, of yarn breakage, in case the rotation of the main shaft 42 passes a predetermined angle. When the operator inches or reverses, the main controller 50 normally makes the main motor 40 rotate or reverse the warp beam 14 or the take-up roller 28 by an amount equivalent to preset one pick to maintain the cloth fell 22 at a proper position by advancing or retreating the cloth fell 22.
In the database 58, the amount of displacement (let-off amount and return amount) of the position of the cloth fell 22 and the cover factor CF are systematically constituted for each device.
Leveling of the shedding device
By leveling of the shedding device is meant an operation of the weft bar preventing apparatus 78, from when the loom 10 stops operating till when an operator restores the cause of stoppage, to dissolve synchronization of the heald frame 18 and the main shaft 42 of the loom 10, for example, by driving the heald frame through an actuator such as a hydraulic cylinder (not shown) to close the shedding of the warp yarns 12.
For instance, when the loom 10 is weaving twill or satin weave, a certain heald frames 18 are located at upper or lower positions even at cross timing when the center shed is closed. Consequently, if the loom 10 is in stoppage for a long period, it results in a state that the warp yarns 12 and the cloth 26 form a shedding, and the cloth fell 22 and the shedding move in the shedding direction (moving direction of the warp yarns 12, i.e., forward or backward direction). To prevent such a weft bar from generating, the shedding device 37 is made to perform leveling action.
When the leveling action of the shedding device 37 is made, the cloth fell 22 is prevented from moving its position due to unbalance in tension of the upper and lower warp yarns 12.
The database 58 is systematically constituted as to whether or not the shedding device 37 is performing leveling action or the shedding amount of the heald frames 18 and the cover factor CF.
Kickback
Before starting the loom 10, the warp beam 14 or the take-up roller 28 is rotated or reversed by a predetermined amount to displace the position of the cloth fell 22 forward and backward in the warp running direction. This enables to compensate excess or shortage in reed beating force in a predetermined period from starting the loom 10 in a state of transitional rotating state of the loom main shaft.
The database 58 is systematically constituted as to the order of normal rotation and reverse rotation, the rotation amount, rotation speed and the cover factor CF for each device.
Also, with respect to "fell control," "inching/reverse return" and "kickback," the set point T induced from the date base 58 makes the weft inserting pick a criterion. Actually, therefore, the let-off controller 52 or the take-up controller 74 calculates the drive amount of the let-off motor 34 or the take-up motor 46, respectively, from the moving length relative to the warp yarns 12 or the cloth 26 on the basis of a value such as the weft beating density and a mechanical factor, and rotates the warp beam 14 or the take-up roller 28. The set points to be stored in the database 58, however, does not necessarily make the weft pick as a basis, but it is possible to make the moving length of the warp or the cloth stored.
Starting method
An operator selects beforehand one among the steps shown in the following (A), (B) and (C), for example, as a set point of the weft preventing apparatus, to start the loom 10.
(A) Ordinary starting method
Firstly, after the loom 10 stopped due to occurrence of a cause for stopping, the main shaft 42 is reversed at a low speed until the standby angle reaches 300° where the warp shedding is brought to a closed state.
The operator performs inching or reversing to make necessary restoration such as removing a mis-inserted weft yarn or repairing a broken yarn, and positions the main shaft 42 at the standby angle (300°). Next, by operating the operation button of the loom 10, the main shaft motor 40 is started, and immediately after the angle θ of the main shaft 42 passed 0°, beating is started, and weft insertion is immediately started.
(B) Back start (blank beating start)
This method is the same as the ordinary method in (A) with respect to reverse the main shaft 42 back to the standby angle (300°) from the occurrence of stoppage of the loom 10 until the warp shedding gets closed, and further, with respect to locating the main shaft 42 at the standby angle (300°) after restoring the cause of stopping. By operating the operation button of the loom 10, firstly the main shaft 42 is reversed at a low speed from the standby position (300°) up to a predetermined starting angle.
Next, until reaching the standby angle (300°) at the time when the main shaft motor 40 is started operating, the weft is not inserted (that is, blank beating is done), and then, the weft insertion is started after the angle θ of the main shaft 42 passes 0°.
(C) Method of starting at 60°
From when the cause of stopping occurred until the loom 10 stops, this method is the same as the starting methods in (A) and (B) above. It differs, however, in that the main shaft 42 is reversed up to the standby angle (60°) to avoid beating up.
The operator, thereafter, to remove the cause of stopping, performs inching or reversing operation for necessary restoration and locate the main shaft 42 at the standby angle (60°). Then, by operating the operation button of the loom 10, the main shaft motor 40 is started and the weft insertion is immediately started.
The database 58 is systematically constituted as to a selected starting method and the cover factor CF. The database 58 also systematically constitutes one or more angle timing set points such as a selected mode of the starting methods, a period of blank beating (reversal stopping angle, the number of blank beating), the standby angle and the predetermined angle and the cover factor CF.
One thread insertion
After the operation button 66 is operated and inched at a low speed toward the vicinity of a predetermined angle (120 - 200°) at which the warp yarns 12 is in a shedding state, then the weft inserting device is actuated to insert one thread of the weft 24, and thereafter the main shaft 42 is inched to the standby angle (300°). Thereafter, the main shaft motor 40 is started to start weft insertion according to the selected mode of the foregoing starting method.
The database 58 is systematically constituted as to whether or not there is any operation of one-thread insertion and the cover factor CF.
Starting torque
This means the starting torque of the main motor 40 at the time when the operation button is operated, and the starting torque can be changed by selecting the magnitude of the power (voltage) supplied to the main shaft motor 40. When a light filling bar (a phenomenon that the weft density becomes coarse) is generated, the loom 10 should be rotated at a higher torque than usual to raise the beating torque of the starting time. Then, from the viewpoint of saving the power, it is restrained to the usual torque to rotate continuously.
The database 58 is systematically constituted as to the magnitude of the starting torque and the cover factor CF.
Starting torque switching control
This means a period to return the starting torque to the above-mentioned usual torque after starting the main shaft motor 40 in the foregoing "starting torque" control. According to setting of the period for returning the starting torque to the usual torque to be slow or fast, it is possible to switch the beating force after the start of the main shaft motor 40 by a synergistic by combination with the above-mentioned "starting torque" control.
The database 58 is systematically constituted as to a switching timing (including the number of picks) to return a high torque to the usual torque and the cover factor CF. Here, the switching timing preferably uses an elapsed time from a reference angle or the angle of the main shaft as a criteria.
The weft bar preventing action suffices to be at least one of the above-listed operations, and it is also possible to adopt those other than the above or to combine with those listed above. Also, when a plurality of weft bar preventing apparatus 78 are used, it is possible to make operation modes of the plural weft bar preventing apparatus 78 different from each other.
Here, the cover factor representing a crowding state of yarns can be expressed by: cover factor CF = warp cover factor CFw + weft cover factor CFp, but warp cover factor CFw = A*2.54/√B, weft cover factor CFp = C/√D, and weft cover factor CFp = C/√D. Each parameter as input information as a basis for calculating the cover factor, namely, parameter A shows the number of warp yarns per unit weaving width dimension, parameter B the thickness of the warp yarn (yarn number count), parameter C the set beating density, and parameter D the thickness of the weft yarn 24 (yarn number count).
Concretely, parameter A can be obtained by the total number of warp yarns/reed drawing-in width. Accordingly, parameter A is calculated on the basis of the total number of warp yarns and the reed drawing-in width which are input information on the warp.
An operator inputs each of parameters A, B, C and D which become the basis for calculation of the cover factor, and has the CPU 62 calculates the cover factor based on the inputted values. In place thereof, however, it can be also considered that the operator directly inputs the cover factor itself obtained by himself through the touch panel 56.
Here, the cover factor means numerized state (degree) of crowding of yarns. In other words, the cover factor reflects a difficulty in beating the weft 24 as it stands.
The so-called weft bar (i.e., suspended stage generated accompanying stoppage of the loom as an object of the present invention) is a phenomenon of unevenness in the density of the weft 24. On the other hand, the cover factor is a numerized crowding state (degree) of yarns. In other words, the cover factor reflects a difficulty in beating the weft 24 as it stands.
According to the study by the inventors, in a cloth with a coarse density (with a small CF value), beating the inserted weft 24 only once results in a final weaving density. In a high-density cloth (with a large CF value), however, beating the inserted weft 24 several times results in a final weaving density.
The inventors looked into the relationship between the cover factor and the beating condition for obtaining a predetermined weft density, and found out there is a correlation between the operation mode of the weft bar preventing apparatus 78 and the cover factor representing a crowding state of yarns.
In view of this, it is quite preferable and self evident to set an operation mode of the weft bar preventing apparatus 78 by turning one's attention to the cover factor CF as information for setting an operation mode suitable for the specification of the cloth, namely, according to the value of the cover factor CF (i.e., degree of difficulty in beating the weft 24).
Thus, it is possible to move the cloth fell position, to raise the beating torque and to beat up a plural times, which are desired weft bar preventing actions, by searching a set value of an operation mode of the weft bar preventing action corresponding to the information on the specification of cloth from the database 58 on the basis of the information on the input specification of cloth, deciding the operation mode of the searched weft bar preventing action and automatically setting. Even an operator having a little experience can carry out the weft bar preventing action with the operation mode which takes a crowding state of yarns into account, so that a quality cloth can be efficiently produced.
The above-mentioned set point deciding apparatus 54 can be made as follows.
As information on the specification of cloth, for example, there are kind of cloth (spun fabric in general, ground fabric, wool, etc.), kind of texture (1/1 plain weave, 2/1, 3/1 twilled weave, 4/1, 5/1 satin weave, fancy weave, dobby pattern and the like).
For this reason, in contrast with the systematical constitution between the cover factor and the operation mode as shown in Table 1, the database 58 may be systematically constituted with further addition of kinds of cloth and textures of cloth as shown in Table 2. Needless to say, in contrast to the systematical constitution as shown in Table 1, either one or both of the foregoing can be included in the information on the specification of cloth.

[Table 2]

name of cloth				spun fabric in general											synthetic fiber in general
kind of texture				1/1 (plain weave)			2/1.3/1 ... (twill weave)				4/1,5/1... (satin weave)		dobby pattern		1 / 1 (plain wave)
set point				cover	factor (CF	value)	cover factor (CF value)				cover factor (CF value)		cover factor (CF value)		cover factor (CF value)
name of weft bar preventing action		object device	contents of setting	~ 19.9	~ 34.9	35.0 ~	~ 14.9	~ 29.9	~ 39.9	40.0 ~	~ 14.9	~ 29.9	~ 14.9	~ 29.9	~ 14.9	~ 29.9
1	fell control	take-up device	operation on/off	×	×	×	×	×	○	○
			operation amount	-	-	-	-	-	a1	a2
		let-off device	operation	×	×	×	×	×	○	○
			operation amount	-	-	-	-	-	b1	b2
2	inching let-off	take-up device	operation amount	c1	c1	c1	c2	c2	c2	c2
		let-off device	operation amount	d1	d1	d1	d2	d2	d2	d2
3	reverse let-off	take-up device	operation amount	c1'	c1'	c1'	c2'	c2'	c2'	c2'
		let-off device	operation amount	d1'	d1'	d1'	d2'	d2'	d2'	d2'
4	shedding device leveling	shedding device	operation amount	×	×	×	×	×	○	○
5	kickback	take-up device	operation on/off	×	×	×	×	×	×	×
			with/without time control	×	×	×	×	×	×	×
			operation amount 1 (rotation amount 1)	-	-	-	-	-	-	-
			operation amount 2 (rotation amount 2)	-	-	-	-	-	-	-
			operation amount 3 (reversal amount 1)	-	-	-	-	-	-	-
			operation amount 4 (reversal amount 2)	-	-	-	-	-	-	-

		let-off device	operation on/off	○	×	○	○	○	○	○
			with/without time control	×	×	○	×	×	○	○
			operation amount 1 (rotation amount 1)	e11	e11	e13	e16	e16	e17	e18
			operation amount 2 (rotation amount 2)	e11'	e11'	e13'	e16'	e16'	e17'	e18'
			operation amount 3 (reversal amount 1)	e21	e21	e23	e26	e26	e27	e28
			operation amount 4 (reversal amount 2)	e21'	e21'	e23'	e26'	e26'	e27'	e28'

6	start	main shaft drive	starting method	G1	G1	G2	G1	G1	G2	G2
			timing 1	-	-	h1'	-	-	h1	h1'
			timing 2	-	-	h2'	-	-	h2	h2'
7	one-threed insertion	weft inserting device	operation on/off	×	×	○	×	×	○	○

8	starting torque	main shaft drive	starting torque	j1	j1	j2	j1	j1	j2	j2
			switching timing	k1	k1	k1	k1	k1	k1	k1
			number of switching picks	l1	l1	12	l1	l1	12	12

operation on X operation off a1...l2 show numerical values (concrete values and relation in magnitude among symbols are omitted). G1 - G2 show kinds of starting methods.

When the CPU 62 fails to search a set point T coinciding the information as a result of searching the database 58 on the basis of the information on the specification of cloth, it is possible to search again on a close condition to this information and output the set point T as calculated from a plurality of searched operation modes by calculation for interpolation.
The CPU 62 may be constituted so that, in place of employing the database 58, the set point T is calculated by a function which is pre-incorporated into the memory 60 and makes the information on the specification of the cloth a parameter.
The set point deciding apparatus 54 may be provided, not to be used in common with the setter of the loom 10 but to be exclusively used for the weft bar preventing apparatus 87.
The set point deciding apparatus 54 may also be constituted by a computer to be used in common with plural looms 10. In this case, for example, the setters and the computers of respective looms 10 are connected so as to be communicated by a wire or wireless network. The output information to be outputted from the set point deciding apparatus 54 may be displayed in the display portion of the setter of the loom 10.
The set point deciding apparatus 54 may be constituted by a personal computer provided in a control chamber of the loom 10. In this case, the set point deciding apparatus 54 may print out the output information on paper, and an operator may set the weft bar preventing apparatus 78 on the basis of the outputted information printed out on the paper as outputted.
The foregoing embodiment may be modified as follows:
The database which stores the cover factors and set points of operation modes of the weft bar preventing operation is previously provided from a loom manufacturer, but more preferably, a user such as a manufacturer or a textile factory modifies the database or constitute so as to add a shortage in the database according to their past results.
For looms to which the present invention can be applied, not only to a loom for weaving always on a single weaving condition during operation but also, for example, to a loom which changes some of the weaving conditions such as kinds of the weft yarns, weft beating density and fabric texture mentioned above in accordance with rotation of the main shaft of the loom. In this case, based on the input information on the specification of cloth which previously change every time of weft insertion pick, operation modes of the weft bar preventing operation corresponding to the weaving conditions are preset for every weft insertion pick and, when the loom stopped, the corresponding weft bar preventing operation may be performed.
In this embodiment, the cover factor CF is a value resulting from adding two basic cover factors, namely, a value resulting from adding the warp cover factor CFw and the weft cover factor CFp. However, it is possible to pay attention, for example, to either one of the two basic cover factors (that is, only to the warp cover factor CFw or only to the weft cover factor CFp), and to decide the operation mode of the weft bar preventing operation to correspond thereto.
The present invention is not limited to the above embodiment but can be variously modified without departing from its purport.

Claims

A set point deciding apparatus (54) comprising an input device (56) for inputting information on cloth, and an output device (56, 58, 60, 62, 64) for deciding and outputting at least one set point of operation modes of a weft bar preventing apparatus of a loom,
wherein said information on the cloth includes either one of a cover factor indicating a crowding state of the cloth or values to be basis for said cover factor,
wherein said output device includes a database (58) in which set points on a plurality of operation modes in a weft bar preventing action are pre-stored in correspondence to said information on the cloth, and search means (62) for searching set points of corresponding operation modes of said database on the input the information on cloth from said database, and
wherein said output device, based on the input cover factors or cover factors obtained as information on said cloth, searches set points of the operation corresponding thereto from said database and decides and outputs the searched set points as set points of operation modes of said weft bar preventing apparatus.
A set point deciding apparatus claimed in claim 1, wherein values to be the basis for said cover factors include the number of warp yarns per unit weaving width, thickness of the warp yarns, and values on weft beating density and the thickness of the weft yarns,
wherein said output device (56, 58, 60, 62, 64) further includes means (62) for calculating cover factors from the values as the basis for said cover factors, and wherein the values as the basis for said cover factors are inputted through said input device, and
wherein said output device includes calculating cover factors from values as the basis for said cover factors, searches set points corresponding to said calculated cover factors from said database, and decides and outputs the searched set points as said set points.
A set point deciding apparatus claimed in claim 1 or 2, wherein said information on cloth further includes information relative to a kind of cloth or a fabric texture, said database (58) pre-storing set points on said plurality of operation modes in correspondence to at least any one of the kind of said cloth or said fabric texture, and
wherein said output device searches set points corresponding thereto from said database on the basis of at least one piece of information and said cover factors among the information relative to said kind of cloth or fabric texture and decides and outputs the searched set points as said set points.