JPH108335A - Control of false twister - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling a false twister capable of prolonging a belt life as long as possible and preventing deficiency in number of twists, etc. SOLUTION: This method for controlling a false twister comprises a stage of nipping pressure control by a nipping pressure control part 21 for measuring the untwisting tension of yarn and controlling the nipping pressure of a nip twister 7 and a stage of revolving speed control by a revolving speed control part 22 for controlling the revolving speed of the nip roller 7 according to the nipping pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a false twisting machine using a nip twister, and more particularly to a method for controlling a nip pressure and a rotation speed of the nip twister to appropriately maintain the untwisting tension of the nip twister. .

[0002]

2. Description of the Related Art A false twisting machine has a large number of false twisting units. Each false twisting unit performs twisting by running the yarn while applying twist and tension to the yarn. One example of each false twisting unit of such a false twisting machine is shown in FIG.

[0003] The false twisting machine comprises a number of false twisting units 1 arranged side by side in the direction perpendicular to the paper. Each false twisting unit 1 draws a yarn (filament yarn) Y from a yarn supply package 3 supported by a creel stand 2. The first feed roller 4 is provided. The yarn Y that has passed through the first feed roller 4, the primary heater 5, and the balloon control plate 6 in this order is subjected to false twist by the nip twister 7. False Yarn Y
Is wound on a winding package 12 by a winding device 11 through a tension sensor 15, a second feed roller 8, a secondary heater 9, and a third feed roller 10 in this order, and the false twisting is completed.

The nip twister 7 is provided with a pair of intersecting belts 13 and 14, and twists and feeds the yarn Y between the belts 13 and 14. The twist formed by the nip twister 7 propagates to the first feed roller 4 and is fixed by the primary heater. That is, the upstream side of the nip twister 7 is the twisting side, and the downstream side is the untwisting side.

As described above, the belt type nip twister 7 is
The yarn is pushed and pinched by two endless belts crossing and contacting each other, and the yarn is fed and twisted by rotating the two belts respectively. The nip pressure (also called contact pressure) of these belts or their rotation speed (also called belt surface speed) affects the tension of the untwisted yarn, and the untwisting tension affects the quality and quality of the untwisted yarn. Affects properties. Further, even at the same nip pressure and rotation speed, the untwisting tension changes due to the aging of the belt.

FIG. 6 shows the influence of the aging of the belt on the untwisting tension (quality). That is, when operating a long time to give a constant nip pressure between the rotational speed, the belt is untwisting tension at T2 ₀ of new is that the level of M (standard), untwisting tension until after a few days T2 ₁ Falls to the level of L (thin). Then gradually return to the level of M, it reaches the level of the D (dark) at time T2 ₂ further rises, thereafter stabilizes at the level of D. It takes about one month for the belt to adjust. Beyond a stable period of several months at the level and D, it can not be adjusted even tension be changed nip pressure and rotational speed eventually intensified suddenly untwisted tension T2 _3. This is the life of the belt. The expired belt can be replaced with a new one, but if it is replaced, the quality will fluctuate for the first month.

[0007] Therefore, the quality and properties of the yarn are made uniform by adjusting the nip pressure and keeping the untwisting tension constant. Specifically, a tension sensor (measuring device) for measuring the untwisting tension of the yarn is provided downstream of the belt-type nip twister so that the tension can be constantly monitored.
For controlling the tension, a control target value is set in advance, and the measured tension is compared with the control target value. If the measured value is different from the target value, the nip pressure of the belt is adjusted based on the difference. If the nip pressure of the belt is adjusted, the yarn tension changes downstream of the belt nip pressure, so that the measured value can approach the target value.

On the other hand, the rotation speed control for controlling the rotation speed of the nip twister also affects the untwisting tension (quality).
Therefore, it is known to control the untwisting tension by increasing or decreasing the rotation speed of the nip twister. Changing the number of rotations of the common rotary drive source of the nip twister of all weights of the false twisting machine with a change pulley, etc., and increasing VR expressed as belt surface speed / yarn speed to appropriately control the untwisting tension. Has been done.

[0009]

However, in the above-described method of controlling a false twisting machine by nip pressure control, even if the nip pressure of the nip twister is controlled, an increase in untwisting tension may not be suppressed ( T2 ₃ state that occurs later in FIG. 6). If the control of the untwisting tension is lost, the number of twists is insufficient (knitted fabric failure). Therefore, when the control of the untwisting tension is lost, it is determined that the belt has reached the end of its service life, and the belts of the nip twister of all the weights of the false twisting machine are replaced simultaneously. Therefore, there is a problem that the belt life is shortened because the belt is still usable and the belt is replaced all at once.

On the other hand, in the method of controlling a false twisting machine by the above-described rotation speed control, the number of rotations of a rotary drive source common to the nip twister of all weights of the false twisting machine is changed by a change pulley or the like.
Since the VR expressed as the belt surface speed (rotation speed) / yarn speed is increased to appropriately control the untwisting tension, there is a problem that the change in the rotation speed is troublesome.

In general, the nip pressure control is relatively easy to control for each weight, whereas the rotational speed control is difficult to control for each weight, and collective control is generally used. That is, according to the nip pressure control, there is a problem that it is difficult to manage all weights, and according to the rotation speed control, it is difficult to manage each weight.

The present invention has been made in view of such problems of the prior art, and the inventions of claims 1 and 2 extend the life of the belt as much as possible and prevent the occurrence of insufficient number of twists and the like. It is an object of the present invention to provide a method of controlling a false twisting machine that can perform the twisting. A third object of the present invention is to provide a method of controlling a false twisting machine according to a preferable combination of each weight control and the whole weight control.

[0013]

According to a first aspect of the present invention, there is provided a method for controlling a false twisting machine provided with a large number of weights for false-twisting a yarn with a nip twister. And a nip pressure control step of controlling the nip pressure of the nip twister, and a rotation speed control step of controlling the rotation speed of the nip twister according to the nip pressure. When it becomes difficult to control the nip pressure, the rotation speed of the nip twister is controlled according to the nip pressure.

According to a second aspect of the present invention, in the first aspect, an upper limit value and a lower limit value are provided for the nip pressure, and when the nip pressure deviates from the upper limit value or the lower limit value, the rotation speed control is performed. The rotation speed control of claim 1 is performed when the nip pressure exceeds a control range between the upper and lower limits, and the nip pressure is suppressed to a predetermined range.

According to a third aspect of the present invention, in the first or second aspect, the nip pressure is detected as an average value of a plurality of representative weights, and the rotation speed control is performed uniformly for all weights. The nip pressure control is performed for each weight, and the rotation speed control of all weights is performed based on the nip pressure control of the representative weight.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a control block diagram of a false twister used in the method of the present invention, and FIG. 2 is a diagram showing a control procedure according to the method of the present invention.

FIG. 1 shows a case where the nip pressure and the rotation speed can be controlled for each weight. Therefore, for one nip twister 7, the nip pressure control unit 21
And the rotation speed control unit 22 are provided.

The nip pressure control section 21 is a nip twister 7
The T2 controller 23 of the tension sensor 15, a T2 range setting device 24 for the T2 controller 23, a pneumatic controller 25 operated by a command from the T2 controller 23, and a pneumatic converter 26. . The T2 controller 23 converts the output from the tension sensor 15 and compares the output with the output from the T2 range setting device 24. The T2 controller 23 converts the output from the tension sensor 15 into a predetermined control range defined by the T2 range setting device 24. This is for raising and lowering the air pressure from the pneumatic controller 25 so that the untwisting tension can be appropriately reduced. That is, the pneumatic controller 25 controls the air from the air source 27 to a predetermined pressure based on a command from the T2 controller 23. The pneumatic converter 26 is a pneumatic controller 2
5 converts the output air pressure into an electric signal.
One of the pair of belts 13 and 14 of the nip twister 7 can be pressed against the other by a pneumatic cylinder, and is configured to generate a nip pressure according to the air pressure output from the pneumatic controller 25.

The rotation speed control unit 22 includes a controller 31 which operates by receiving an electric signal from the pneumatic converter 26, an air pressure range setting unit 32 for the controller 31, and an inverter 33 which operates according to a command from the controller 31.
And a motor 34 controlled by an inverter 33. The controller 31 receives the output from the pneumatic converter 25, compares the output with the output from the pneumatic range setter 32, and determines a predetermined control range (the upper limit and the lower limit with respect to the target value) determined by the pneumatic range setter 32. A command for changing the number of rotations of the motor 34 (that is, the rotation speed of the nip twister) is output to the inverter 33 so that the nip pressure falls within a typical range. The pair of belts 13 and 14 of the nip twister 7 run around a driving pulley, and have a structure in which the rotation speed of the belt is determined by the rotation speed of the motor 34.

Next, control of the nip twister 7 by the control block of FIG. 1 will be described with reference to FIG. FIG. 3A shows the change over time of the untwisting tension T2, FIG. 3B shows the change over time of the nip pressure P, and FIG. 3C shows the motor rotation speed RPM.
4 shows a change with time of the relationship (correlated with the rotation speed of the nip twister). The T2 range setting unit 24 shown in FIG.
As in, and outputs the upper limit value T2 _MAX and the lower limit value T2 _MIN with respect to the target value T2 _0. T2 as before
Is within the control range, the T2 controller 23 does not perform an output for changing the air pressure, so that the nip pressure P is kept at the target value P ₀ , for example, as shown in FIG. .

T2 is equal to the upper limit value T2 _MAX after time.
Is exceeded, the pneumatic controller 25 increases the air pressure in response to a command from the T2 controller 23.
Then, time to reach the upper limit value T2 _MAX gradually lowered untwisting tension T2, the untwisting tension T2 is returned to the management range.
Then, stop the command to raise the air pressure from T2 controller 23, as shown in FIG. 2 (b), the nip pressure P is constant value within the upper limit value P _MAX. Similarly, the time from to time, when the untwisting tension T2 is less than the lower limit T2 _MIN, decreases the nip pressure P, the untwisting tension T2 is returned to the management range, the nip pressure P is constant.

The pneumatic range setting unit 32 shown in FIG.
As in (b), the output upper limit value P _MAX and the lower limit value P _MIN with respect to the target value P _0. From time to time, the untwisting tension T2 increases again, and the time reaches the upper limit T2.
_When it exceeds _MAX , the pneumatic controller 25 increases the air pressure in response to a command from the T2 controller 23. However, as time, the nip pressure P is even reached the upper limit value P _MAX, the untwisting tension T2 is generated that does not return to the management range. In this case, the controller 31 to which the nip pressure is input via the pneumatic converter 26 compares the nip pressure with the input of the pneumatic range setter 32 to determine the upper limit value P of the nip pressure P.
_MAX is detected, and a command to increase the rotation speed of the motor 34 is output via the inverter 33. This state is shown in FIG.
It is shown as the time of (c). The motor speed gradually increases from R1 to R2 from time to time. Then, the surface speed of the belt of the nip twister 7 increases,
VR expressed by belt surface speed / yarn speed becomes large,
The untwisting tension T2 in FIG. 2A gradually decreases from time to time.

In time, the untwisting tension T2 is lower than the lower limit T2 _MIN
, The nip pressure P starts to decrease, and at the same time, the motor 3
4 is stopped, and the motor rotation speed becomes constant at R2 as shown in FIG. 2C. The nip pressure P decreases from time to time, and when the untwisting tension T2 returns to the control range over time, the nip pressure P becomes constant.

As described above, when the rotation speed of the nip twister 7 is controlled in accordance with the nip pressure P, the rise of the nip pressure P can be stopped. In particular, when an upper limit value _PMAX and a lower limit value _PMIN are set for the nip pressure P, the rotation speed of the nip twister 7 is controlled so that the nip pressure _stays within a control range between the upper limit value _PMAX and the lower limit value _PMIN. Can be Therefore, due to the nip pressure rising too much,
Abnormal belt wear and kogation can be prevented, and abnormal twist count due to too small nip pressure can also be prevented.

Although the embodiments of FIGS. 1 and 2 have described the case where the nip pressure control of the nip twister and the rotation speed control are performed for each weight, in particular, the rotation speed control prepares an inverter-controlled motor for each weight. It is necessary, and it becomes large. The case where the nip pressure control for each weight and the rotation speed control common to all weights are performed will be described with reference to the block diagram of FIG.

In FIG. 3, the false twisting machine has 12 false weights of the false twisting unit 1 arranged in a row to form a span S1, and a span from the span S1 to the span S12 forms a row. Further, the false twist unit 1 having a bilaterally symmetric shape centered on the side of the secondary heater 9 of the false twist unit 1 described with reference to FIG.
Further, another row is formed from span S13 to span S24, and a false twisting machine having a total of 288 weights is configured.

In the illustrated example, although the nip pressure control unit 21 is provided for each of the 288 weights, the electropneumatic converter 26 is mounted on only 12 weights of the span S1. Only one rotation speed control unit 22 is provided for the false twisting machine. The output from the 12-pneumatic electropneumatic converter 26 is input to the controller 31, where the output is averaged (averaging means), and the averaged nip pressure is set in the air pressure range setting device 32. The configuration is such that the rotation speed of the motor 34 is controlled via the inverter 33 so as to fall within the management range. The output of the motor 34 is connected to the first output shaft 36 and the second output shaft 36 via a transmission mechanism such as a timing belt and a pulley.
The nip twister, which is divided into an output shaft 37 and has two rows of back-to-back weights, is rotationally driven by a common motor 34.

The nip pressure control unit 21 for each weight is used when the operation conditions for each weight are different, such as when the belt or the like of the nip twister is abnormally worn when the heater or the like on the upstream side of the nip twister is defective. Available. The change with time of the belt as described with reference to FIG. 5 is handled by the rotation speed control unit 22 common to all the weights. Accordingly, the rotation speed control unit 22 is capable of coping with the fluctuation of the untwisting tension corresponding to the situation of each weight and the simultaneous change of the belt with time due to the simultaneous replacement of the belt.
This can prevent the belt life from being shortened due to the nip pressure being too high, and can also avoid troublesome rotation speed control for each cone. Note that, instead of the nip pressure control for each weight, the nip pressure control may be performed for all weights, such as spans, for each smaller group.

Next, a specific example of the nip pressure control unit 21 for each nip twister will be described with reference to FIG. First, the method of adjusting the nip pressure of the nip twister 7 will be briefly described. One of the belts 13 and 14 is fixed, and the other is swingably supported. Two valves for expanding and contracting a cylinder for the swing are provided. One valve acts on the cylinder in a direction of pressing the swingable belt against a fixed belt, and the other valve swings. The cylinder acts in a direction away from the fixed belt.

The nip pressure mechanism will be described in detail. In the figure, the nip twister 7 is provided with a pair of endless belts 13 and 14 that intersect to twist and feed with a yarn Y interposed therebetween. Each of the belts 13 and 14 is a frame 1
Pulley 116 and driven pulley 117 supported by
It is wound around. The rotation directions of the belts 13 and 14 are indicated by arrows B1 and B2, respectively. The belt 14 shown by a solid line is swingably supported to adjust the nip pressure on the fixed-side belt 13, and a cylinder 125 and a valve
The nip pressure adjusting means 140 composed of 31 and 132 is operated by the pneumatic controller 25 to be pressed by the fixed belt 13 to adjust the nip pressure.

The driving pulley 116 and the driven pulley 117
The touch roller 118 is supported by the touch roller 118.
The belt 8 is rotatably supported by the frame 115 and rotates the touch roller 118 so that the belt 14 can swing in the direction of arrow R shown in the figure around the same axis as the drive pulley 116. In this touch roller 118,
Although not shown, the drive shaft is inserted, and the drive pulley 116 is driven by a motor or the like. A holder 119 is attached to the touch roller 118. The holder 119 has three lever portions 120, 121, 122
The first lever portion 120 includes a swinging belt 1
A nip pressure adjusting pin 124 provided with a spring 123 for urging the belt 4 away from the fixed belt 13 is in contact with the belt. A piston 126 of a cylinder 125 that presses and biases the oscillating belt 14 against the fixed belt 13 against the force of the spring 123 is in contact with the second lever portion 121. By turning the lever 127a connected to the stopper pin 127 that regulates the maximum position of the swing-side belt 14, the third lever 122 can open the gap between the belts 13 and 14 greatly. I have.

The cylinder 125 includes a reserve tank 128
, And an air pressure supply pipe 129 is connected to the reserve tank 128. The air pressure supply pipe 129 has an orifice 130 of, for example, about 0.1 mm inside, and the upstream side is branched into two branches, and a valve 131 (hereinafter, referred to as a first valve) 131 that supplies an upper limit air pressure u to one of the branches. Is connected to the other end, and a valve (hereinafter, referred to as a second valve) 132 for supplying a lower limit air pressure Pd is connected to the other end. Orifice 1
30 and the reserve tank 128 are provided to prevent air pressure pulsation. The upstream side of the first valve 131 that supplies the upper limit air pressure Pu is connected to an air pressure supply source, and the upstream side of the second valve 132 that supplies the lower limit air pressure Pd is connected to a supply source separate from the upstream air pressure supply source. Or connected to an upper air pressure supply via a pressure reducing valve or the like. The upper limit air pressure Pu and the lower limit air pressure Pd are set according to the type of yarn and the belt speed.

To adjust the nip pressure, when the first valve 131 is opened, the upper limit air pressure Pu acts on the reserve tank 128 via the orifice 130. As a result, the cylinder 12
5 gradually increases, the nip pressure of the belts 13 and 14 increases, and the untwisting tension decreases. First valve 131
Is closed, the cylinder 125 maintains the increased pressure during that time, and the belts 13 and 14 are maintained at the same nip pressure. When the second valve 132 is opened, the lower limit air pressure P
The d acts on the reserve tank 128, and the air pressure of the cylinder 125 decreases, whereby the nip pressure of the belts 13, 14 decreases, and the untwisting tension increases. When the second valve 132 is closed, the belts 13, 14 are maintained at the same nip pressure.

In FIG. 4, a tension sensor 15 for detecting the untwisting tension T of the yarn Y is provided on the yarn path downstream of the belts 13 and 14, and the detection signal is input to the management device 1 described later. It has become. With such a compact structure, the nip pressure control unit 21 can be provided for each weight.

[0035]

As described above, according to the first aspect of the present invention, the nip pressure control step of measuring the untwisting tension of the yarn and controlling the nip pressure of the nip twister; A rotation speed control stage for controlling the rotation speed of the nip twister.In consideration of the rotation speed control when the nip pressure increases, the nip pressure does not become abnormally high, and the life of the belt constituting the nip twister is shortened. And the occurrence of kogation on the belt is reduced. Also,
It is also possible to prevent twist number abnormality due to abnormally high or low nip pressure.

According to the second aspect of the present invention, when the nip pressure is out of the upper limit or the lower limit, the rotation speed is controlled.
The nip pressure control in the first aspect is reliably performed, and the effect of the first aspect is ensured.

According to the third aspect of the present invention, the nip pressure is detected as an average value of one or a plurality of representative weights, and the rotation speed control is performed uniformly for all weights. Therefore, the nip pressure control is performed for each weight or group. Control corresponding to abnormality of individual devices such as heaters is performed for each weight or group, and control corresponding to aging of the belt is performed collectively, thereby enabling control of the right person in the right place.

[Brief description of the drawings]

FIG. 1 is a control block diagram of one spindle of a false twister used in the method of the present invention.

FIG. 2 is a diagram showing a control procedure according to the method of the present invention.

FIG. 3 is a control block diagram of the entire false twisting machine.

FIG. 4 is a perspective view showing a specific device configuration of the nip twister.

FIG. 5 is a device configuration diagram of a false twist unit.

FIG. 6 is a graph showing a temporal change in untwisting tension due to a change with time of the belt.

[Explanation of symbols]

 7 Nip Twister 13 Belt 14 Belt 15 Tension Sensor 21 Nip Pressure Control Unit 22 Rotation Speed Control Unit 23 T2 Controller 24 T2 Range Setter 25 Pneumatic Controller 26 Electropneumatic Converter 31 Controller 32 Pneumatic Range Setter 33 Inverter 34 Motor

Claims (3)

[Claims] 1. A method for controlling a false twisting machine having a large number of weights for false twisting a yarn with a nip twister, wherein the nip pressure of the nip twister is controlled by measuring the untwisting tension of the yarn. And a rotation speed control step of controlling the rotation speed of the nip twister according to the nip pressure. 2. The method of controlling a false twisting machine according to claim 1, wherein an upper limit value and a lower limit value are provided for the nip pressure, and when the nip pressure deviates from the upper limit value or the lower limit value, the rotation speed control is performed. 3. The method of controlling a false twisting machine according to claim 1, wherein the nip pressure is detected as an average value of a plurality of representative weights, and the rotation speed control is performed uniformly for all weights.