JP2007126797A - Method for controlling yarn feed of knitting machine and apparatus for positive yarn feed - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To regulate the amount of yarn feed in the course of knitting while preventing an increase in cost, complication of control, remarkable delay of response and limitation, etc., on knitting speed in an apparatus for positive yarn feed for a circular knitting machine, etc. <P>SOLUTION: The apparatus for positive yarn feed is designed to keep a yarn feed wheel 14 in a rotating state on the basis of actual rotation taken out of a driving part 5 on the knitting machine side and in such a state as to produce differential rotation by an originally controllable motor 39 to be controlled. The target amount of the yarn feed of the driving part 5 on the knitting machine side is set on the basis of the knitting conditions. The speed change ratio necessary for the differential rotation is determined so as to keep the reference amount of the yarn feed at the target amount of the yarn feed when the yarn feed wheel 14 is rotated only by the actual rotation. The motor 39 to be controlled is controlled by a control value obtained by multiplying the rotational speed detected from the actual rotation by a speed change ratio. The yarn feed wheel 14 is rotated by an output rotation obtained by mechanically synthesizing the differential rotation relatively to the actual rotation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a yarn feeding control method for controlling the amount of yarn feeding to a knitting machine during knitting, and an active yarn feeding device that can be used to implement this yarn feeding control method.

In a knitting machine such as a circular knitting machine, an apparatus for supplying a yarn to a portion where a knitting needle is performing a knitting operation includes an active yarn feeding device that forcibly supplies a yarn while driving the yarn, and a knitting machine side There are depolarized yarn feeders that supply naturally by handing the yarn, but among these yarns, the negative yarn feeder has the disadvantage that it is difficult to obtain a stable yarn feed amount due to the friction of the yarn. There is a demand to adopt a yarn device.
However, in the active yarn feeding device, it is necessary to adjust the yarn feeding amount according to the knitting state on the knitting machine side in order to prevent yarn breakage due to insufficient yarn feeding amount and yarn slackening due to excessive yarn feeding amount. This is, for example, when changing the knitting conditions such as the size of the knitted fabric, stitch amount, yarn gauge, knitting structure, etc. This is to distribute the driving force to the driving pulley of the yarn feeding wheel before starting the knitting (distribution source B) It was dealt with by adjusting the outer diameter of the main pulley. Adjustment of the outer diameter of the main pulley involves troublesome and complicated adjustment work such as tension adjustment of the transmission belt. Further, when there are a plurality of yarn types to be used, such as knit, it is necessary to set a yarn supply amount corresponding to each yarn type.

By the way, it is a circular fabric such as stockings that has a large change in the cylinder diameter in the longitudinal direction, or a fabric in which a large knitting structure with a large loop and a small knitting structure with a loop are mixed. When knitting using a knitting machine, it is necessary to change the yarn supply amount (circumferential yarn length) per rotation of the cylinder during the knitting.
Many positive yarn feeders have a mechanical interlocking structure in which the drive is taken out from the rotation drive shaft of the cylinder to the drive pulley by belt transmission via the main pulley, and the yarn feed wheel is rotated by this drive pulley. As described above, there is only a method for adjusting the outer diameter of the main pulley to change the yarn supply amount. However, to adjust the outer diameter, the yarn supply must be stopped once. That is, changing the yarn supply amount while the cylinder is rotating (during knitting) cannot be handled by the positive yarn feeder of this mechanical interlocking structure. As a result, when knitting stockings or the like, a negative yarn feeding device had to be adopted.

Conventionally, in order to respond to the change in the yarn feed amount during knitting in the active yarn feeder, the rotation of the cylinder has been adopted as a configuration in which an independently controllable motor such as a servo motor or pulse motor is used as the drive motor for the yarn feed wheel. A yarn feed control method has been proposed in which the drive motor of the yarn feed wheel is controlled as desired without being influenced by the number (see, for example, Patent Document 1).
JP 2001-159056 A

In a conventional yarn feeding control method (Patent Document 1) in which a servo motor or the like is employed as a drive motor for a yarn feeding wheel in an active yarn feeding device, the speed control range for the drive motor is set to stop the yarn feeding wheel. It covers the entire range (zero to max) from the state to the rotational speed at which the required yarn feed amount is obtained.
Therefore, high-speed calculation is required to calculate the control amount of the drive motor, but it is inherently inevitable that the response delay caused by this calculation will be avoided. Requires a high-speed computing device. Such a high-speed arithmetic device is expensive and has a problem of complicated control.

Even with a high-speed arithmetic device, there is a limit to suppressing the influence of the response delay. For example, a tubular fabric such as a stocking (a fabric that requires frequent yarn feed amount adjustment) is knitted. In some cases, the knitting speed has a limitation of speeding up (in some cases, deceleration is forced).
Furthermore, in order to implement this yarn feeding control method, it is preferable to use a high-function servomotor for the drive unit on the knitting machine side, but in order to realize this, the production cost as a knitting machine increases. However, when the drive unit on the knitting machine side is already an induction motor, there is a drawback that it is difficult to modify the servo motor specification.

  The present invention has been made in view of the above circumstances, and does not cause various inconveniences such as high cost, complicated control, significant response delay, limitation on knitting speed, and the like. It is possible to provide a yarn feeding control method and a positive yarn feeding device for a knitting machine that can be used suitably for knitting of a fabric that requires a large amount of yarn feeding adjustment, such as stockings. Objective.

In order to achieve the above object, the present invention has taken the following measures.
That is, the yarn feeding control method for a knitting machine according to the present invention is as follows. First, as a premise of the device, the yarn feeding wheel is rotated based on the actual rotation mechanically taken out from the knitting machine side drive unit, and the difference from the actual rotation is controlled by a controlled motor that can be controlled independently. It is in a state where rotation can be generated.
Based on the knitting conditions, the target yarn feed amount of the knitting machine side drive unit is set, and the reference yarn feed amount when the yarn feed wheel is rotated only by the actual rotation is within a range approximating the target yarn feed amount. By setting, a speed change ratio that the differential rotation should bear on the target yarn feed amount is determined, and based on a control value obtained by multiplying the rotational speed detected from the actual speed by the speed change ratio, The rotational direction and rotational speed of the differential rotation by the control motor are controlled, the differential rotation is mechanically synthesized with the actual rotation, and the yarn feeding wheel is rotated by the obtained output rotation. The size of the fabric, the amount of stitches, the gauge of yarn, the knitting structure, and the like, especially here including those that change during knitting. In addition, in the calculation for obtaining the control value, conversion considering the gear ratio of the gear element included in the transmission system, the diameter ratio of the pulley element, and the like is added.

The reference yarn feed amount is theoretically preferably set at the middle position of the control range, but in actual control, the stepping motor adopted as the controlled motor is set at the upper limit position or lower limit position of the control range. It can be said that it is preferable because it is easy to control.
As described above, in the yarn feeding control method for a knitting machine according to the present invention, the drive (output rotation) for rotating the yarn feeding wheel is mechanically taken out from the driving unit on the knitting machine side as the base (actual output). Rotation) is used, and if necessary, the differential rotation is combined to increase the speed or to reduce the speed to create a rotation speed for obtaining the target yarn feeding amount.

As a result, in controlling the rotational speed of the yarn feeding wheel, the control performed in the present invention has a small control amount compared to the case where the drive motor is controlled independently and independently (the control range is zero to max). (Control range is base rotation to max).
Therefore, when knitting a fabric that requires a large amount of yarn supply adjustment during knitting, for example, stockings, it has excellent follow-up by control, and also has the effect of preventing the occurrence of yarn breakage and yarn slack. It gets higher that much. Of course, it is not necessary to perform troublesome and highly skilled adjustment work such as adjusting the outer diameter of the main pulley and adjusting the tension of the transmission belt.

The yarn feeding control method of the knitting machine according to the present invention is not limited to the case where the knitting machine is a circular knitting machine, and can also be implemented for a flat knitting machine or the like.
The active yarn feeding device according to the present invention includes a yarn feed amount setting unit, a drive take-out unit, a speed compensation unit, a speed synthesis unit, a yarn feed drive unit, and a control unit.
The yarn feed amount setting unit sets the rotational speed and the target yarn feed amount of the knitting machine side drive unit based on the knitting conditions, and the drive takeout unit is a place where the actual rotation is mechanically taken out from the knitting machine side drive unit. In other words, the speed compensation unit generates differential rotation separately from actual rotation.

Further, the speed synthesizing unit mechanically synthesizes the actual rotation and the differential rotation, and the yarn feeding drive unit is a place where the yarn feeding wheel is rotated by the output rotation extracted by the speed synthesizing unit.
Then, the control unit calculates the rotational direction and rotational speed of the differential rotation required to obtain the target yarn feeding amount from the reference yarn feeding amount when the yarn feeding wheel is rotated only by actual rotation, and obtained. The speed compensation unit is controlled by a control value.
With the active yarn feeding device according to the present invention having such a configuration, the yarn feeding control method for the knitting machine according to the present invention can be implemented.

Since the active yarn feeding device according to the present invention has the above-described configuration, it is not necessary to use a high-function servomotor as the driving unit on the knitting machine side, and a normal induction motor may be used. Therefore, there is no possibility that the production cost as a knitting machine will increase. This also means that the yarn feeding control method of the knitting machine according to the present invention can be easily implemented by modifying the existing knitting machine (with the drive unit having an induction motor specification) (need to change to a servo motor). Therefore, it can be implemented at a low price).
A differential gear mechanism may be employed for the speed synthesis unit. The differential gear mechanism has three shafts, a first input shaft and a second input shaft, and an output shaft that receives the operations of both input shafts simultaneously. Of these, the first input shaft is driven out. The second input shaft may be allocated to the speed compensation unit, and the output shaft may be allocated to the yarn feeding drive unit.

It is preferable to employ a stepping motor for the speed compensation unit. In addition to the stepping motor, a servo motor or the like can be used for the speed compensation unit. However, the stepping motor is more suitable for cost reduction.
The knitting machine capable of implementing the active yarn feeding device according to the present invention is not limited to a circular knitting machine, a flat knitting machine, a double machine, or a single machine.

  In the yarn feeding control method and active yarn feeding device of the knitting machine according to the present invention, without incurring any inconvenience such as high cost, complicated control, large response delay, limitation on knitting speed, etc. The yarn feed amount can be adjusted. Therefore, this positive yarn feeding device can be suitably used for knitting fabrics that require a large amount of yarn feeding adjustment, such as stockings.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 4 shows an embodiment of a knitting machine 2 comprising the active yarn feeding device 1 according to the present invention. The knitting machine 2 of the present embodiment is a circular knitting machine for double knitting. As a needle bed portion for holding a knitting needle row, a cylindrical cylinder 3 and a disk-shaped dial provided on the cylinder 3 are provided. 4. The cylinder 3 and the dial 4 can be rotated integrally with the center of the cylinder 3 and the dial 4 as a rotation axis P, and are driven to rotate in one direction by a driving unit 5 for rotation.
Naturally, the knitting needles held in the cylinder 3 are cylinder needles 7, and a large number of them are lined up with the longitudinal direction thereof being directed in the vertical direction and surrounding the entire outer peripheral surface of the cylinder 3, and can be moved up and down independently. . A lower cam member 8 is provided around the cylinder 3 in a stationary state. A cylinder for causing each cylinder needle 7 to move up and down (knitting operation) at a predetermined timing on the inner peripheral surface of the lower cam member 8. A cam (not shown) is provided.

The knitting needles held by the dial 4 are the dial needles 9, and the same number as the cylinder needles 7 are arranged in a radial arrangement from the center on the upper surface of the dial 4 with the longitudinal direction thereof in the radial direction of the dial 4, It can move laterally. An upper cam member 10 is fixedly provided on the upper portion of the dial 4, and a dial cam (not shown) for causing the dial needle 9 to move laterally (knitting operation) is provided on the lower surface of the upper cam member 10. Is provided.
As the drive unit 5 rotates the cylinder 3 and the dial 4 (needle bed portion) as a unit, the drive unit 5 makes the cam member (the cylinder cam of the lower cam member 8 and the dial cam of the upper cam member 10) relative to each other. A driving force for movement is generated.

That is, the cylinder needle 7 moves up and down following the cylinder cam, and the dial needle 9 moves laterally along the dial cam. Of these, the needle tip (hook part) of the cylinder needle 7 that has been raised and the dial needle 9 that has advanced A knitting position R is formed at the intersection with the needle tip (hook part), and the cylindrical fabric W is knitted by supplying yarn to the knitting position R. The drive unit 5 does not have to employ a high-performance motor such as a servo motor, and may be a normal induction motor.
The tubular fabric W knitted by the drive of the drive unit 5 is hung down through the inside of the cylinder 3 and taken up by a take-up device 13 provided via a suspension frame 12 below the cylinder 3.

The active yarn feeding device 1 is arranged above the outer peripheral portions of the cylinder 3 and the dial 4 and corresponding to each forming position of the knitting position R (for example, 16 or 32 around the cylinder 3). A plurality of yarn supply wheels 14 are provided. By rotating the yarn supply wheel 14, the yarn is unwound from a yarn stock portion (not shown) installed at a separate location, and the yarn is knitted at a knitting position R. Supply towards That is, feed driving can be applied to this yarn (forced supply).
The yarn supply wheel 14 is provided with a number equal to the number of formation of the knitting position R or a multiple according to the type of yarn used, but a portion for driving the yarn supply wheel 14 (hereinafter referred to as “pulley drive portion 15”). May be provided in a state in which a plurality or all of the yarn feeding wheels 14 are interlocked with each other, or may be provided separately for each individual yarn feeding wheel 14. Further, when the pulley driving portion 15 is provided for each yarn supplying wheel 14, the pulley driving portion 15 and the yarn supplying wheel 14 may be connected directly, or the yarn supplying wheel 14 may be connected to the pulley support portion. It is good also as a separation transmission type which connects between the pulley drive part 15 and the yarn feeding wheel 14 with the belt transmission means 17 etc., after hold | maintaining freely by 16.

As shown in FIG. 1 to FIG. 3, the active yarn feeding device 1 is roughly divided into device elements and control elements. Among these, the drive extraction unit 20, the speed compensation unit 21, and the speed are included as device elements. The synthesizing unit 22 and the yarn feeding drive unit 23 are provided, and the control elements include the yarn feeding amount setting unit 24 and the control unit 32.
[Equipment element]
The drive extraction unit 20 mechanically extracts the actual rotation by the drive unit 5, the speed correction unit 21 generates differential rotation separately from the actual rotation obtained by the drive extraction unit 20, and the speed synthesis unit 22 The actual rotation obtained by the drive extraction unit 20 and the differential rotation generated by the speed compensation unit 21 are mechanically combined. The yarn feeding drive unit 23 rotates the yarn feeding wheel 14 by the output rotation taken out by the speed synthesis unit 22.

The drive extraction unit 20 has an input shaft 26 that is rotatably held in a shaft holder 25. A driving pulley 27 (see FIG. 4) is provided on the rotary shaft P of the knitting machine 2, and a driven pulley (not shown) is connected to the one end portion 26a of the input shaft 26 so as to be integrally rotatable. By connecting the two pulleys with the belt transmission means 28, the drive rotation by the drive unit 5 can be extracted to the input shaft 26, and the rotation of the input shaft 26 is extracted to the other end portion 26b. Output can be performed by connecting the gear 29 and the like so as to be integrally rotatable.
The speed compensation unit 21 has a controlled motor 39 capable of highly accurate rotation control. As the controlled motor 39, for example, a stepping motor or a servo motor is employed. A stepping motor is suitable if importance is attached to cost or ease of control.

A differential gear 44 for outputting rotational drive as “differential rotation” directed to the speed synthesis unit 22 is coupled to the rotation shaft 39a of the controlled motor 39 so as to be integrally rotatable.
If the controlled motor 39 is provided with a self-holding function, an effect of maintaining the rotation stop state at the time of a power failure or the like can be obtained. Further, by providing this self-holding function, it is possible to prevent a problem that the controlled motor 39 rotates with a reverse load at the time of a power failure or the like, and in this sense, it can be said that the yarn breakage is prevented. .
The speed synthesizing unit 22 employs a differential gear mechanism. This differential gear mechanism has three shafts: a first input shaft 46, a second input shaft 47, and an output shaft 48 that simultaneously receives the operations of both the input shafts 46 and 47.

The first input shaft 46 is formed as a rotation support shaft for the intermediate gear 37 that meshes with the take-out gear 29 of the drive take-out portion 20 and has an interlocking relationship. A first side gear 50 is inserted into the first input shaft 46 so as to be integrally rotatable. The first side gear 50 and the intermediate gear 37 are bolted together, so that the first input shaft 46, the first side gear 50, and the intermediate Three members of the gear 37 can rotate together.
That is, the first input shaft 46 is present in the differential gear mechanism and assigned to the drive take-out unit 20 and is simultaneously driven to rotate by the rotation of the input shaft 26 of the drive take-out unit 20. . The first side gear 50 is a bevel gear.

The second input shaft 47 is a rotating shaft 39 a of the controlled motor 39 provided in the speed compensation unit 21. That is, the second input shaft 47 is present in the differential gear mechanism and is allocated to the speed correction unit 21 and is driven to rotate as the rotation of the controlled motor 39 itself of the speed correction unit 21. Become.
As described above, the differential gear 44 is provided on the second input shaft 47 so as to be integrally rotatable. The differential gear 44 is meshed with a large gear 51 that is supported rotatably around the first input shaft 46. The large gear 51 is provided with a pair of two pinion gears 52 arranged to face each other at a symmetrical position with the first input shaft 46 as a center. Both pinion gears 52 are bevel gears meshed with the first side gear 50, and their rotation axes are coaxial with the diameter axis of the large gear 51, and are rotatable around the rotation axis.

Therefore, when the large gear 51 rotates around the first input shaft 46, the two pinion gears 52 revolve while revolving along the outer peripheral portion (tooth portion) of the first side gear 50.
The output shaft 48 is held by the first input shaft 46 in a skewered manner so as to face the first side gear 50, and the second side gear 53 is rotatably held around the first input shaft 46. It is formed as a boss that protrudes from the side gear 53 in the opposite direction to the first side gear 50.
A pulley 55 is fitted on the output shaft 48. The second side gear 53 and the pulley 55 can be integrally rotated by being connected to each other by bolts. The pulley 55 is engaged with the belt transmission means 17 (see FIG. 4) to drive the yarn feeding wheel 14 to form the yarn feeding drive portion 23.

That is, the output shaft 48 is present in the differential gear mechanism and allocated to the yarn feeding drive unit 23, and transmits a rotational force toward the yarn feeding drive unit 23.
Such a speed synthesizer 22 has the following effects. Now, the first input shaft 46 and the first side gear 50 are rotated from the drive take-out part 20 via the intermediate gear 37, while the speed compensation part 21 is in a stopped state, and the second input is input to the large gear 51. It is assumed that a brake action (rotation stop action) occurs via the shaft 47 and the differential gear 44.
Since the large gear 51 is stopped, the two pinion gears 52 do not revolve, but only rotation due to meshing with the first side gear 50 occurs. Therefore, the second side gear 53 that is meshed with both the pinion gears 52 at the position facing the first side gear 50 rotates in the reverse direction at the same speed ratio (1: 1) as that of the first side gear 50, and is integrated with this. Thus, the pulley 55 is rotationally driven via the output shaft 48. In other words, it can be explained that the pulley 55 is reversely rotated in the direct connection state (no control state) in response to the rotation of the drive extraction unit 20.

Next, it is assumed that the operation of the speed compensation unit 21 causes the large gear 51 to rotate in the same direction as the first input shaft 46 and at a half speed through the rotation of the second input shaft 47 and the differential gear 44. Then, both the pinion gears 52 tend to rotate together with the revolution. However, since the revolution speed of both the pinion gears 52 is half the rotational speed of the first side gear 50, the revolution action and the rotation action of each pinion gear 52 are canceled out. As a result, each pinion gear 52 does not rotate or rotate, and the rotational drive is not transmitted to the second side gear 53. Accordingly, the output shaft 48 and the pulley 55 are stopped.
Contrary to this, the operation of the speed compensation unit 21 from the stop state of the large gear 51 causes the large gear 51 to rotate in the opposite direction to the first input shaft 46 and half through the rotation of the second input shaft 47 and the differential gear 44. When the rotation of the first speed is applied, the revolution and rotation of the pinion gears 52 are synergistic. Therefore, the second side gear 53 is transmitted to the second side gear 53 by the double speed rotation drive of the first side gear 50, and the output shaft 48 And the pulley 55 also rotates integrally therewith.

In this way, a situation occurs in which the first input shaft 46 and the output shaft 48 rotate together. If the large gear 51 is rotated in the same direction as the first input shaft 46 from this situation, the first input shaft 46 is rotated. The output shaft 48 can be stopped with respect to 46, and can naturally be decelerated during the process. Conversely, if the large gear 51 is reversed, the output shaft 48 with respect to the first input shaft 46 is reversed. Can be increased.
If the rotation speed of the output shaft 48 is always controlled on the deceleration side with reference to the rotation of the first input shaft 46, the rotation direction of the large gear 51 is limited to the same direction as the first input shaft 46. It can be used to perform only its speed control. On the contrary, if the rotation speed control of the output shaft 48 is always performed on the speed increasing side with reference to the rotation of the first input shaft 46, the rotation direction of the large gear 51 is limited to the reverse rotation with respect to the first input shaft 46. Then, it can be used to perform only the speed control.
[Control elements]
The yarn feed amount setting unit 24 performs various artificial settings by keyboard input or the like, and the control unit 32 obtains and instructs the rotation speed when the differential rotation is generated by the speed correction unit 21 by calculation. .

The setting items in the yarn feed amount setting unit 24 include the rotational speed of the drive unit 5 and the target yarn feed amount, and the gear ratio that the speed compensation unit 21 should bear. The rotational speed of the drive unit 5 and the target yarn feed amount are obtained from empirical rules and know-how based on the knitting conditions such as the size of the knitted fabric, the stitch amount, the yarn gauge, the knitting structure, and the knitting schedule (temporal factor). .
The speed change ratio is substantially equal when the yarn feeding wheel 14 is rotated only by actual rotation by the drive unit 5 (that is, the first input shaft 46 and the output shaft 48 are in the above-described direct connection state in the speed synthesizing unit 22. When the pulley 55 is rotated by the first input shaft 46), the yarn supply amount supplied by the rotation of the yarn supply wheel 14 is set as the “reference yarn supply amount”, and this reference yarn supply amount is set as the target yarn supply amount. In order to make it a quantity, the ratio of how much differential rotation is generated in the speed compensation unit 21 is said. For example, assuming a relationship in which the reference yarn feed amount is 10: 9 with respect to the target yarn feed amount, the difference by the speed compensation unit 21 is calculated based on the shortage of the reference yarn feed amount (1/10 of the target yarn feed amount). It means to supplement by rotation.

The control unit 32 has an actual rotation detection unit 33 for detecting the rotation speed of the actual rotation by the drive unit 5, and the rotation speed of the drive unit 5 and the target yarn supply amount set by the yarn supply amount setting unit 24. And a calculation unit 41 that performs a predetermined calculation using the data detected by the actual rotation detection unit 33 and various data in the storage unit 40.
The actual rotation detection unit 33 of the present embodiment employs a rotary encoder 35, and a detection gear 36 is connected to a rotation shaft 35 a of the rotary encoder 35 so as to be integrally rotatable, and the detection gear 36 is connected to the speed synthesis unit 22. The first input shaft 46 is engaged with an intermediate gear 37 provided so as to be integrally rotatable, and is interlocked.

As described above, the intermediate gear 37 is also meshed with the take-out gear 29 of the drive take-out portion 20, and the drive rotation obtained by the drive take-out portion 20 is transmitted to the detection gear 36 through the intermediate gear 37. The actual rotation detection unit 33 can detect the rotation speed of the actual rotation extracted from the drive unit 5.
The calculation unit 41 calculates a control value by multiplying the rotation speed of the actual rotation detected by the actual rotation detection unit 33 by the gear ratio, and outputs the control value to the controlled motor 39 of the speed correction unit 21. To do. Note that this control value is converted by taking into account the gear element tooth ratio, pulley element diameter ratio, etc. included in each transmission system from the drive unit 5 to the rotary encoder 35 and from the pulley 55 to the yarn feeding wheel 14. Is required to do. In this way, the differential rotation generated by the speed compensation unit 21 is controlled to the required rotational direction and rotational speed.

Next, the yarn feeding control method for the knitting machine according to the present invention will be described based on the operation status of the knitting machine 2 including the positive yarn feeding device 1.
Based on various knitting conditions relating to the size of the knitted fabric, stitch amount, yarn gauge, knitting structure, knitting schedule (temporal factor), the operator can set the rotational speed of the drive unit 5 and the target supply to the yarn supply amount setting unit 24. Set the thread amount. In parallel, assuming that the reference yarn feed amount when the yarn feed wheel 14 is rotated only by actual rotation is set in a range approximating the target yarn feed amount, the differential rotation is relative to the target yarn feed amount. Determine the gear ratio that should be borne.

  Next, the driving unit 5 on the knitting machine 2 side is driven, and the knitting machine 2 starts fabric knitting. Along with this, the input shaft 26 of the drive extraction unit 20 also starts to rotate together with this, so that the actual rotation is mechanically extracted from the drive unit 5. At this stage, the control unit 32 electrically detects the current rotational speed of the drive unit 5 by the rotary encoder 35 of the actual rotation detection unit 33. The detected electrical signal means a reference yarn feeding amount that is fed by the rotation of the yarn feeding wheel 14 when the yarn feeding wheel 14 is rotated only by the actual rotation by the drive unit 5.

The control unit 32 multiplies the detected rotational speed by the speed change ratio to obtain a control value. And based on this control value (transmission system conversion value), a rotation direction and a rotation speed are controlled about the differential rotation by the controlled motor 39 of the speed compensation unit 21.
The differential rotation generated in this way is mechanically combined with the actual rotation by the speed combining unit 22, and the rotation drive to the yarn supplying wheel 14 is taken out from the yarn supplying drive unit 23 as the output rotation obtained after the combining. Thus, the yarn feeding wheel 14 rotates properly and is fed properly from the positive yarn feeding device 1 toward the knitting position R formed in the knitting machine 2.

  As described above, the drive (output rotation) for rotating the yarn feeding wheel 14 is mechanically taken out from the drive unit on the knitting machine side (actual rotation) as the base, and as needed, Therefore, when the rotational speed of the yarn supplying wheel 14 is controlled independently and independently, the rotational speed of the yarn supplying wheel 14 is controlled separately (control). Compared with the range (zero to max), the control amount is small (the control range is the base rotation to max). Since the control amount is small in this way (the control range is narrow), even if a response delay occurs here, the delay amount is negligible.

Therefore, for example, when knitting a fabric that requires a large amount of yarn supply adjustment, such as stockings, it has excellent follow-up by control, and it has the effect of preventing the occurrence of yarn breakage and yarn slack. Get higher. Of course, it is not necessary to perform troublesome and highly skilled adjustment work such as adjusting the outer diameter of the main pulley and adjusting the tension of the transmission belt.
The yarn feeding control method and active yarn feeding device of the knitting machine according to the present invention are not only useful when knitting a fabric that requires a large amount of yarn feeding adjustment, such as stockings, but for example, a cylinder Even when a tubular fabric having a constant diameter is knitted, it is effective to appropriately follow the yarn feed amount against the acceleration / deceleration change of the drive unit 5 that occurs when the knitting machine 2 is started or stopped.

By the way, this invention is not limited to the said embodiment, It can change suitably according to embodiment.
For example, in the differential gear mechanism employed in the speed synthesizing unit 22, the number of pinion gears 52 is not particularly limited as long as there is at least one pinion gear 52.
The differential gear mechanism is planarly configured to include a sun gear, a carrier that holds a planetary gear that rotates and revolves around the sun gear, and a ring gear that surrounds the planetary gear. It is also possible to replace the type.

It is the top view which showed one Embodiment of the active yarn feeding apparatus which concerns on this invention. It is a BB arrow directional cross-sectional view of FIG. It is AA arrow sectional drawing of FIG. It is the sectional side view which showed the knitting machine (circular knitting machine) which comprised the active yarn feeding apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Positive yarn feeder 2 Knitting machine 5 Drive part 14 Yarn supply wheel 20 Drive take-out part 21 Speed compensation part 22 Speed synthetic | combination part 23 Yarn feed drive part 46 1st input shaft 47 2nd input shaft 48 Output shaft

Claims (4)

While the yarn feeding wheel (14) is rotated based on the actual rotation mechanically taken out from the knitting machine side drive section (5),
In a state where a differential rotation different from the actual rotation can be generated by the controlled motor (39) that can be controlled independently,
Based on the knitting conditions, set the target yarn feed amount of the knitting machine side drive unit (5),
The differential rotation bears on the target yarn feed amount by setting the reference yarn feed amount when the yarn feed wheel (14) is rotated only by the actual rotation to a range approximating the target yarn feed amount. To determine the gear ratio
Based on the control value obtained by multiplying the rotational speed detected from the actual rotation by the speed ratio, the rotational direction and rotational speed of the differential rotation by the controlled motor (39) are controlled,
This differential rotation is mechanically combined with the actual rotation,
A yarn feeding control method for a knitting machine, wherein the yarn feeding wheel (14) is rotated by the obtained output rotation. A yarn feed amount setting unit (24) for setting the rotational speed and the target yarn feed amount of the knitting machine side drive unit (5) based on the knitting conditions;
A drive take-out part (20) for mechanically taking out the actual rotation from the knitting machine side drive part (5);
A speed compensation unit (21) for generating differential rotation separately from the actual rotation;
A speed synthesizer (22) that mechanically synthesizes the actual rotation and the differential rotation;
A yarn feeding drive unit (23) for rotating the yarn feeding wheel (14) by the output rotation taken out by the speed synthesis unit (22);
It is obtained by calculating the rotational direction and rotational speed of the differential rotation required to obtain the target yarn feed amount from the reference yarn feed amount when the yarn feed wheel (14) is rotated only by the actual rotation. And a control unit (32) for controlling the speed compensation unit (21) with a control value.   The speed synthesizing unit (22) includes three shafts: a first input shaft (46, 47) and an output shaft (48) that receives the actions of both input shafts (46, 47) simultaneously. A differential gear mechanism having a first input shaft (46) is allocated to the drive take-out section (20), a second input shaft (47) is allocated to the speed compensation section (21), and an output shaft (48) is supplied. 3. The active yarn feeding device according to claim 2, wherein the positive yarn feeding device is employed in the form of being allocated to the yarn driving section (23).   The active yarn feeding device according to claim 2 or 3, wherein a stepping motor is employed for the speed compensation section (21).

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