JP7554072B2 - Yarn Winding Machine - Google Patents

Description

The present invention relates to a yarn winding machine.

Patent Document 1 discloses a yarn winding machine that winds a running yarn onto a bobbin to form a package. More specifically, the yarn winding machine includes a traverse device having a traverse guide for traversing the yarn along the axial direction of the bobbin, a winding section that rotates the bobbin, and a roller (feed roller) that sends the yarn to the winding section. Tension is applied to the yarn due to the speed difference between the winding speed at which the yarn is wound onto the bobbin and the yarn feed speed at which the yarn is fed by the feed roller (in other words, the yarn winding machine includes a tension applying section that applies tension to the yarn being wound onto the bobbin). By controlling this tension to a predetermined value, a package with a predetermined winding density according to the application is formed.

Here, the tension actually applied to the yarn may vary due to the reciprocating movement of the traverse guide. For example, in a specified traverse direction , when the traverse guide moves from the center to the end in the region where the traverse guide moves back and forth , the tension may increase unintentionally due to the yarn path becoming longer or the yarn being pulled outward in the traverse direction by the traverse guide in the region where the traverse guide moves back and forth . Also, in the region where the traverse guide moves back and forth, when the direction of the traverse guide is switched from the outside to the inside in the traverse direction, the tension may decrease unintentionally due to the yarn path becoming shorter or the tension of the yarn by the traverse guide temporarily relaxing. Such tension fluctuations can be suppressed by a control device such as a computer (tension adjustment unit), for example, controlling the yarn feed speed. For example, Patent Document 2 proposes a means for controlling the yarn feed speed using information on the position of the traverse guide.

WO2020075383A1 EP1318097B1

There is a certain amount of time lag (delay) between when the tension adjustment unit acquires tension adjustment information that takes into account the position (and/or speed) of the traverse guide and when the tension is actually adjusted. The time lag occurs due to, for example, the time required for calculation processing by the tension adjustment unit and the time required for the tension application unit to respond. Due to this delay, for example, when the traverse cycle is short (the traverse guide moves quickly), the actual tension adjustment may not be able to adequately track the tension fluctuations caused by the movement of the traverse guide. This can cause a problem in which the tension fluctuations cannot be adequately suppressed. Patent documents 1 and 2 do not mention the time lag as described above.

The objective of the present invention is to effectively suppress tension fluctuations caused by the reciprocating movement of the traverse guide.

The yarn winding machine of the first invention is a yarn winding machine that winds a running yarn onto a bobbin, and includes a traverse device having a traverse guide for traversing the yarn along the axial direction of the bobbin, a tension applying unit that applies tension to the yarn being wound onto the bobbin, and a control unit. The control unit includes a prediction information acquisition unit that acquires prediction information regarding at least one of a future predicted position and a predicted speed of the traverse guide, and a tension adjustment unit that controls the tension applying unit based on adjustment information regarding the adjustment of the tension. The tension adjustment unit acquires the adjustment information corresponding to a predetermined first time in association with the prediction information corresponding to a second time that is a predetermined time later than the first time.

In the present invention, adjustment information corresponding to a certain first time is acquired in association with predicted information corresponding to a second time a predetermined time after the first time (i.e., a predetermined time in the future). "Acquired in association" means that there is some kind of relationship (calculation, linking, etc.) between the adjustment information corresponding to the first time and the predicted information corresponding to the second time. The predetermined time can be set or determined, etc., taking into account the above-mentioned time lag (delay).

As a result, the tension adjustment unit can output a signal related to the tension adjustment that should actually be performed at the second time a predetermined time earlier than the second time. This allows the delay to be compensated for and the tension to be adjusted at an appropriate time. Therefore, the tension fluctuation caused by the reciprocating movement of the traverse guide can be effectively suppressed.

The yarn winding machine of the second invention is the same as the first invention, but the predetermined time is shorter than the reciprocating period of the traverse guide.

In the present invention, the specified time is short, less than the reciprocating period of the traverse guide. This makes it possible to suppress an increase in the error between the predicted position and/or predicted speed of the traverse guide corresponding to the second time, which is predicted at the first time, and the actual position and/or speed of the traverse guide at the second time. Therefore, the tension can be controlled with high precision.

The yarn winding machine of the third invention is characterized in that, in the first or second invention, it includes a tension detection unit that detects the tension applied to the yarn, and the tension adjustment unit obtains the adjustment information based on the detection result by the tension detection unit.

The tension of the thread can fluctuate not only due to the reciprocating movement of the traverse guide, but also due to other disturbance factors. In the present invention, by acquiring adjustment information based on the detection results by the tension detection unit, feedback control can be performed so that the tension approaches a predetermined target value. Therefore, tension fluctuations due to disturbance factors other than the reciprocating movement of the traverse guide can also be suppressed, making it possible to further stabilize the tension.

The yarn winding machine of a fourth invention is any of the first to third inventions, characterized in that the tension applying unit has a winding unit that winds the yarn around the bobbin and a yarn feeding unit that feeds the yarn to the bobbin, and applies the tension to the yarn based on the speed difference between the winding speed at which the winding unit winds the yarn around the bobbin and the yarn feeding speed at which the yarn feeds to the bobbin, and the tension adjustment unit adjusts the tension by controlling the yarn feeding unit.

In a configuration in which tension is applied to the yarn due to the speed difference between the winding speed and the yarn feed speed, it is also possible to control the tension by controlling the winding speed. However, when trying to control the tension by controlling the winding speed, there is a risk that the winding angle (traverse angle) of the yarn may change unintentionally. In such a case, it becomes necessary to also control the traverse device to suppress the change in the traverse angle, which may complicate the control. In the present invention, the tension is controlled by controlling the yarn feed speed, so the control can be simplified compared to when the winding section is controlled to control the tension.

The yarn winding machine of the fifth invention is any one of the first to fourth inventions, characterized in that the control unit changes the target value of the tension within the reciprocating period of the traverse guide.

In a configuration in which the target tension value is changed within the reciprocating period of the traverse guide, the control of the present invention, which suppresses tension fluctuations by taking into account the above-mentioned time lag, is particularly effective.

The yarn winding machine of a sixth invention is characterized in that, in the fifth invention, the control unit sets the target value when the traverse guide is located at the end of the traverse area in which the traverse guide moves back and forth, in relation to the traverse direction in which the traverse guide moves , to be lower than the target value when the traverse guide is located at the center in the traverse area .

In the traverse region, if the tension in the yarn is large when the traverse guide is located at the end in the traverse direction, the yarn may be unintentionally pulled inward in the axial direction of the bobbin when the traverse guide changes direction. As a result, a larger amount of yarn may be wound inward in the axial direction of the bobbin than the target position, which may cause the package shape to be distorted. In the present invention, the tension in the traverse region when the traverse guide is located at the end in the traverse direction can be reduced. Therefore, the yarn can be prevented from being unintentionally pulled inward in the axial direction of the bobbin when the traverse guide changes direction.

FIG. 2 is a schematic diagram showing the rewinder according to the embodiment as viewed from the front. FIG. 2 is a diagram showing the electrical configuration of a rewinder. 1 is a graph showing the relationship between the position of a traverse guide and time, and a graph showing the relationship between the speed of the traverse guide and time. 11 is a first reference example of a graph showing the relationship between the position of the traverse guide, the rotation speed of the feed roller, and the tension of the yarn, and the time. 13 is a second reference example of a graph showing the relationship between the position of the traverse guide, the rotation speed of the feed roller, and the tension of the yarn, and the time. 11 is a table illustrating the correspondence between the predicted position and predicted speed of the traverse guide and time. 11 is a table illustrating the relationship between a predicted position of a traverse guide at a certain time and the actual number of rotations of a feed roller. 11 is a table showing the relationship between the rotation speed command value of the feed roller and time, taking into consideration a predetermined time lag. 6 is a graph showing the relationship between the position of the traverse guide, the number of revolutions of the feed roller, and the tension of the yarn in the present embodiment and time. 10 is a graph showing the relationship between the position of a traverse guide, the number of revolutions of a feed roller, and the tension of a yarn in a modified example, and the time.

Next, an embodiment of the present invention will be described with reference to Figs. 1 to 9. The up-down direction and left-right direction shown in Fig. 1 are respectively the up-down direction and left-right direction of the rewinder 1. The direction perpendicular to both the up-down direction and left-right direction (the direction perpendicular to the paper surface of Fig. 1) is the front-rear direction. The direction in which the yarn Y runs is the yarn running direction.

(Rewinder Configuration)
First, the configuration of a rewinder 1 (yarn winding machine of the present invention) according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic diagram of the rewinder 1 as viewed from the front. As shown in Fig. 1, the rewinder 1 includes a machine base 11, a yarn supplying section 12, a winding section 13, a yarn sending section 14, and a control device 15 (control section of the present invention). The rewinder 1 is configured to unwind a yarn Y from a yarn supplying package Ps supported by the yarn supplying section 12, and rewind the yarn Y onto a winding bobbin Bw (bobbin of the present invention) by the winding section 13 to form a winding package Pw. More specifically, the rewinder 1 is intended to, for example, more neatly rewind the yarn Y wound around the yarn supplying package Ps, or to form a winding package Pw with a desired density.

The machine stand 11 is provided so as to extend in the vertical direction. The machine stand 11 is provided upright on, for example, a floor surface (not shown). A yarn supplying section 12 is provided in the lower part of the machine stand 11. A winding section 13 is provided in the upper part of the machine stand 11. A yarn sending section 14 is provided in the middle part of the machine stand 11 in the vertical direction.

The yarn supplying section 12 is provided in the lower portion of the machine base 11. The yarn supplying section 12 is configured to support a yarn supply package Ps formed by winding a yarn Y around a yarn supplying bobbin Bs. This allows the yarn supplying section 12 to supply the yarn Y.

The winding unit 13 is configured to wind the yarn Y around the winding bobbin Bw to form a winding package Pw. The winding unit 13 is provided on the upper part of the machine base 11. The winding unit 13 has a cradle arm 21, a winding motor 22, a traverse device 23, and a contact roller 24.

The cradle arm 21 is attached to the machine base 11 so as to be able to swing. The cradle arm 21 is configured to rotatably support the winding bobbin Bw, for example, with the left-right direction being the axial direction of the winding bobbin Bw. For example, a bobbin holder (not shown) that holds the winding bobbin Bw is rotatably attached to the tip of the cradle arm 21. The winding motor 22 is a motor that rotates and drives the bobbin holder. The winding motor 22 is, for example, a general stepping motor. The winding motor 22 may have a rotary encoder (not shown) that detects the rotation angle of the rotating shaft (not shown) of the winding motor 22. The winding motor 22 is configured to be able to change the number of rotations of the rotating shaft (the number of rotations per predetermined time). This allows the winding motor 22 to change the winding speed at which the yarn Y is wound onto the winding bobbin Bw (i.e., the peripheral speed of the surface of the winding package Pw). The winding motor 22 is electrically connected to the control device 15 (see Figure 2).

The traverse device 23 is a device that traverses the yarn Y along the axial direction (left-right direction in this embodiment) of the winding bobbin Bw. The traverse device 23 is disposed immediately upstream in the yarn running direction of the winding package Pw. The traverse device 23 has a traverse motor 31, an endless belt 32, and a traverse guide 33.

The traverse motor 31 is, for example, a general stepping motor. The traverse motor 31 is configured to be able to rotate a rotating shaft (not shown) forward and backward. The traverse motor 31 may have a rotary encoder (not shown) that detects the rotation angle of the rotating shaft (not shown) of the traverse motor 31. The traverse motor 31 is configured to be able to change the number of rotations of the rotating shaft. The traverse motor 31 is electrically connected to the control device 15 (see FIG. 2). The endless belt 32 is a belt member to which the traverse guide 33 is attached. The endless belt 32 is wound around pulleys 34 and 35 arranged at a distance from each other in the left-right direction and a drive pulley 36 connected to the rotating shaft of the traverse motor 31, and is stretched in an approximately triangular shape. The endless belt 32 is driven to reciprocate by the traverse motor 31. The traverse guide 33 is attached to the endless belt 32 and is arranged between the pulleys 34 and 35 in the left-right direction. The traverse guide 33 is caused to move linearly back and forth in the left and right direction by the endless belt 32 being driven back and forth by the traverse motor 31 (see the arrow in FIG. 1). As a result, the traverse guide 33 traverses the yarn Y in the left and right direction (hereinafter also referred to as the traverse direction).

The contact roller 24 is a roller that applies contact pressure to the surface of the winding package Pw to shape the winding package Pw. The contact roller 24 comes into contact with the winding package Pw and rotates in response to the rotation of the winding package Pw.

The yarn feeding section 14 is configured to feed the yarn Y unwound from the yarn supply package Ps to the winding bobbin Bw. The yarn feeding section 14 is disposed between the yarn supply section 12 and the winding section 13 in the yarn running direction. The yarn feeding section 14 has a feed roller 41 and a roller drive motor 42.

The feed roller 41 is a roller around which the yarn Y is wound. The feed roller 41 is, for example, a known nip roller. The feed roller 41 is provided on the front of the machine base 11. The feed roller 41 is configured to rotate and feed the yarn Y downstream in the yarn running direction. The feed roller 41 is rotated by the roller drive motor 42. The roller drive motor 42 is, for example, a general stepping motor. The roller drive motor 42 may have a rotary encoder (not shown) that detects the rotation angle of the rotation shaft (not shown) of the roller drive motor 42. The roller drive motor 42 is configured to be able to change the rotation speed of the rotation shaft. As a result, the roller drive motor 42 can change the rotation speed of the feed roller 41 (i.e., can change the yarn feed speed by the feed roller 41). The roller drive motor 42 is electrically connected to the control device 15 (see FIG. 2). In this embodiment, tension is applied to the yarn Y by the speed difference between the winding speed by the winding unit 13 and the yarn feed speed by the yarn feed unit 14. In other words, the combination of the winding section 13 and the yarn sending section 14 corresponds to the tension applying section of the present invention. In general, the tension increases as the speed difference increases, and the tension decreases as the speed difference decreases.

A yarn guide 16 is disposed below the yarn sending section 14 (upstream side in the yarn running direction). The yarn guide 16 is disposed, for example, on an extension line of the central axis of the yarn supplying bobbin Bs. The yarn guide 16 guides the yarn Y unwound from the yarn supplying package Ps downstream in the yarn running direction. A tension sensor 17 (tension detection section of the present invention) is disposed above the yarn sending section 14 (downstream side in the yarn running direction). The tension sensor 17 is configured to detect the tension applied to the yarn Y traveling from the yarn sending section 14 to the winding section 13. The tension sensor 17 is, for example, a contact-type sensor having a piezoelectric element (not shown), but is not limited to this. The tension sensor 17 is electrically connected to the control device 15 (see FIG. 2). The tension sensor 17 outputs a detection signal to the control device 15. The tension sensor 17 also functions as a fulcrum guide that serves as a fulcrum when the yarn Y is traversed by the traverse guide 33. In addition, a yarn guide (not shown) that functions as a fulcrum guide may be provided downstream of the tension sensor 17 in the yarn running direction.

The control device 15 includes a CPU, a ROM, and a RAM (storage unit 51; see FIG. 2). The storage unit 51 stores parameters such as the winding amount of yarn Y, the winding speed, and the target tension to be applied to yarn Y. The control device 15 controls each part using the CPU in accordance with a program stored in the ROM based on the parameters stored in the storage unit 51. The control device 15 is electrically connected to the winding motor 22, the traverse motor 31, the roller drive motor 42, and the tension sensor 17 (see FIG. 2).

As described below, the control device 15 functions as a winding control unit 52, a traverse control unit 53 (a prediction information acquisition unit of the present invention), and a roller control unit 54 (a tension adjustment unit of the present invention) (see FIG. 2). First, the control device 15 acquires winding information related to a target value for the number of rotations of the winding bobbin Bw (or the winding speed of the yarn Y by the winding unit 13) from the memory unit 51. Based on the winding information, the control device 15 outputs a signal to the winding motor 22 to control the torque of the winding motor 22. In other words, the control device 15 functions as a winding control unit 52 that controls the winding motor 22.

The control device 15 also acquires target traverse information related to the target position and target speed of the traverse guide 33 from the memory unit 51. Based on the target traverse information, the control device 15 outputs a signal to the traverse motor 31 to control the torque of the traverse motor 31. In other words, the control device 15 functions as a traverse control unit 53 that controls the traverse motor 31.

The control device 15 also acquires yarn feed information related to the number of rotations of the feed roller 41 (in other words, the yarn feed speed by the yarn feed unit 14). Based on the yarn feed information, the control device 15 outputs a signal to the roller drive motor 42 to control the number of rotations of the feed roller 41 (more precisely, the torque of the roller drive motor 42). In other words, the control device 15 functions as a roller control unit 54 that controls the roller drive motor 42.

In the rewinder 1 as described above, the yarn Y unwound from the yarn supply package Ps travels downstream in the yarn travel direction. The traveling yarn Y is traversed left and right (traverse direction) by the traverse guide 33 and wound onto the rotating winding bobbin Bw. The tension applied to the yarn Y is controlled to approach a predetermined target tension mainly by adjusting the rotation speed of the feed roller 41 (in other words, by adjusting the yarn feed speed by the yarn feed unit 14). That is, the control device 15 (roller control unit 54) adjusts the rotation speed based on rotation speed adjustment information (adjustment information of the present invention) related to the adjustment of the rotation speed of the feed roller 41, thereby controlling the tension of the yarn Y. Details of tension control will be described later.

(Traverse guide reciprocating movement)
The reciprocating movement of the traverse guide 33 will be described with reference to Fig. 3. The graph on the upper side of Fig. 3 is a graph showing the relationship between the position in the traverse direction of the traverse guide 33 and time. The graph on the lower side of Fig. 3 is a graph showing the relationship between the speed in the traverse direction of the traverse guide 33 and time.

In the graph shown in the upper part of the paper of FIG. 3, the horizontal axis indicates time, and the vertical axis indicates the position of the traverse guide 33 in the traverse direction. For convenience of explanation, the left side of the center of the area (traverse area) in which the traverse guide 33 moves back and forth is the positive direction of the vertical axis of the graph. Also, the right side of the center of the traverse area is the negative direction of the vertical axis of the graph. The traverse guide 33 moves back and forth in the left and right directions by the control device 15 driving and controlling the traverse motor 31. The symbol "T" in FIG. 3 indicates the period in which the traverse guide 33 moves back and forth. As a specific example, when the time is 0 in FIG. 3, the traverse guide 33 is located in the center of the traverse area. When the time is T/4, the traverse guide 33 is located at the left end of the traverse area. When the time is T/2, the traverse guide 33 is located at the center of the traverse area. When the time is 3T/4, the traverse guide 33 is located at the right end of the traverse area. When the traverse guide 33 is located in the center of the traverse area, the yarn path from the fulcrum guide (the tension sensor 17 in this embodiment) to the traverse guide 33 is the shortest. When the traverse guide 33 is located at the end of the traverse area, the yarn path is the longest.

The speed of the traverse guide 33 changes as shown in the graph in the lower part of Fig. 3. As a specific example, when the time is T/4, the moving direction of the traverse guide 33 is switched from left to right in the traverse region . When the time is 3T/4 , the moving direction of the traverse guide 33 is switched from right to left in the traverse region .

(Changes in thread tension due to reciprocating movement of the traverse guide)
Next, the fluctuation in tension accompanying the reciprocating movement of the traverse guide 33 will be described with reference to Figures 4 and 5. Figure 4 is a first reference example of a graph showing the relationship between the position of the traverse guide 33, the rotation speed of the feed roller 41, and the tension of the yarn Y, and time. Figure 5 is a second reference example. In Figures 4 and 5, the graph on the upper side of the page shows the relationship between the position of the traverse guide 33 and time. The graph in the middle in the vertical direction of the page shows the relationship between the rotation speed of the feed roller 41 and time. The graph on the lower side of the page shows the relationship between the tension of the yarn Y and time.

The tension of the yarn Y is roughly determined by the speed difference between the winding speed and the yarn feeding speed as described above. However, the tension actually applied to the yarn Y may vary due to the reciprocating movement of the traverse guide 33. For example, in the traverse region, when the traverse guide 33 moves from the center to the end in the traverse direction, the tension may unintentionally increase due to the yarn path becoming longer or the yarn Y being pulled outward in the traverse direction by the traverse guide 33 in the traverse region . Furthermore, in the traverse region, when the direction of movement of the traverse guide 33 is switched from the outside to the inside at the end in the traverse direction, the tension may unintentionally decrease due to the yarn path becoming shorter or the pulling of the yarn Y by the traverse guide 33 temporarily loosening.

In order to suppress such tension fluctuations, various means have been proposed in the past. As a first reference example, there is a control means for suppressing the tension fluctuations by reflecting the detection result by the tension sensor 17 in the control of the roller drive motor 42. The control is, for example, a general feedback control. The control changes the rotation speed of the feed roller 41, for example, as shown in FIG. 4, and thereby changes the yarn feed speed. However, in this control method, the yarn feed speed is changed after the tension actually fluctuates, so the following problems may occur. For example, when the traverse cycle is short (the traverse guide moves quickly), the adjustment of the yarn feed speed may not be able to keep up with the tension fluctuations caused by the movement of the traverse guide 33. In this case, as shown in FIG. 4, the tension fluctuations cannot be sufficiently suppressed, and the actual tension (see the solid line in FIG. 4) varies from the target tension (see the dotted line in FIG. 4).

A second reference example is a control means that adjusts the yarn feed speed using information about the position and/or speed of the traverse guide 33. In this control, information about the fluctuation in tension according to the position of the traverse guide 33 is taken into consideration for adjusting the yarn feed speed. That is, at the timing when it is predicted that the tension will increase due to the movement of the traverse guide 33, the rotation speed of the feed roller 41 is controlled so that the yarn feed speed increases (see FIG. 5). Also, at the timing when it is predicted that the tension will decrease, the rotation speed of the feed roller 41 is controlled so that the yarn feed speed decreases (see FIG. 5).

However, there is a certain amount of time lag (delay) between when the control device 15 (roller control unit 54) acquires information on the change in the rotation speed of the feed roller 41 and when the rotation speed of the feed roller 41 is actually changed. The time lag is caused by, for example, the time required for calculation processing by the roller control unit 54, the inertial mass of the rotating shaft (not shown) of the roller drive motor 42, and the inertial mass of the feed roller 41. Due to such a delay, for example, when the traverse period is very short (when the movement of the traverse guide 33 is very fast), the yarn feed speed may not be adjusted in time. For this reason, in the means of the second reference example (see FIG. 5), the tension fluctuation can be suppressed more than in the means of the first reference example (see FIG. 4), but the fluctuation may not be sufficiently suppressed (see FIG. 5). Therefore, in this embodiment, in order to effectively suppress the tension fluctuation caused by the reciprocating movement of the traverse guide 33, the control device 15 performs the following control.

(Specific tension control method)
Specific tension control methods by the control device 15 will be described with reference to Figs. 6 to 9. The tension control described below is tension control within one reciprocating cycle (the above-mentioned T) of the traverse guide 33. In this embodiment, the target tension is constant (see the dashed line in the graph at the bottom of Fig. 9). Also, in this embodiment, the winding speed is approximately constant within the reciprocating cycle of the traverse guide 33.

The memory unit 51 stores, for example, a table in which the target position and target speed of the traverse guide 33 are associated with time. Alternatively, the control device 15 may be configured to calculate, for example, the target position and/or the target speed as a function of time. Alternatively, the memory unit 51 may store a table in which one of the target position and target speed of the traverse guide 33 is associated with time. In this case, the control device 15 may calculate information on one of the target position and target speed of the traverse guide 33 based on information on the other. The control device 15 (traverse control unit 53) controls the operation of the traverse motor 31 based on such information on the target position and target speed of the traverse guide 33.

The above target position and target speed information is also used as information (prediction information) of the future position (predicted position) and future speed (predicted speed) of the traverse guide 33, as described later. Specifically, for example, as shown in the table of FIG. 6, the predicted position where the traverse guide 33 is predicted to be located at a specific time t1 (first time of the present invention) is x1. The predicted speed of the traverse guide 33 at time t1 is v1. The predicted position and predicted speed of the traverse guide 33 at time t2 (second time of the present invention), which is a specific time dt after time t1, are x2 and v2, respectively. dt is a time shorter than the round trip period of the traverse guide 33. Similarly, the predicted position and predicted speed of the traverse guide 33 at time t3, which is a specific time dt after time t2, are x3 and v3, respectively.

The relationship between the predicted position of the traverse guide 33 at a certain time and the actual number of rotations of the feed roller 41 at the same time is as shown in the table in FIG. 7. For example, the predicted position of the traverse guide 33 corresponding to time t1 is x1 as described above. The actual number of rotations of the feed roller 41 at time t1 is, for example, n1. n1 is the number of rotations for making the actual tension at time t1 approximately equal to the target tension, taking into account the tension fluctuation of the yarn Y caused by the reciprocating movement of the traverse guide 33. Similarly, the actual number of rotations of the feed roller 41 at time t2 (predicted position x2) is n2. The actual number of rotations of the feed roller 41 at time t3 (predicted position x3) is n3.

As described above, there is a certain amount of time lag (delay) between when the control device 15 (roller control unit 54) acquires information (rotation speed adjustment information) related to adjusting the rotation speed of the feed roller 41 and when the rotation speed of the feed roller 41 is actually changed. If it is assumed that such a time lag is approximately equal to the above-mentioned predetermined time dt, for example, the roller control unit 54 controls the yarn feeding unit 14, for example, as follows. In other words, on the premise that the predetermined time dt is approximately equal to the above-mentioned time lag, the control device 15 is set as follows.

The memory unit 51 stores a function for calculating a command value for the number of rotations of the feed roller 41 (hereinafter, the rotation speed command value) based on, for example, information on the future predicted position and predicted speed of the traverse guide 33 (prediction information). This function is, for example, a function with a fixed coefficient (i.e., the function outputs the same rotation speed command value when the same prediction information is input). The roller control unit 54 receives the prediction information from the traverse control unit 53 and calculates the rotation speed command value using the function. Here, when calculating the rotation speed command value corresponding to time t1 (in other words, information on the control signal to be output from the roller control unit 54 to the roller drive motor 42 at time t1), the roller control unit 54 uses prediction information corresponding to time t2, a predetermined time dt in the future. The prediction information corresponding to time t2 is information on the predicted position and predicted speed of the traverse guide 33 at time t2.

As a specific example, by the traverse control unit 53 sending the prediction information to the roller control unit 54 early, the prediction information corresponding to time t2 can be used to calculate the rotation speed command value corresponding to time t1. As a result, the rotation speed command value corresponding to time t1 becomes n2 (see the table in FIG. 8 and the graph in FIG. 9). In other words, the roller control unit 54 acquires the rotation speed command value (i.e., n2) associated with the predicted position x2 and predicted speed v2 of the traverse guide 33 corresponding to time t2 as the rotation speed adjustment information corresponding to time t1. In other words, the rotation speed adjustment information corresponding to time t1 is acquired in association with the prediction information corresponding to time t2, which is a predetermined time dt in the future from time t1.

This allows the roller control unit 54 to output a control signal for adjusting the rotation speed of the feed roller 41 to n2 a predetermined time dt earlier than time t2 (see the dashed line in the center of the paper in FIG. 9). As a more specific example, the actual rotation speed of the feed roller 41 (see the solid line in FIG. 9) must be the largest just before the traverse guide 33 reaches the outer end in the traverse direction in the traverse area (time t2 in FIG. 9). To achieve this, the timing at which the command value of the rotation speed of the feed roller 41 (see the dashed line in FIG. 9) is the largest is time t1, a predetermined time dt before time t2. This compensates for the above-mentioned time lag (delay), and the rotation speed of the feed roller 41 is adjusted at an appropriate timing. That is, the tension is adjusted at an appropriate timing, and tension fluctuations are effectively suppressed.

The roller control unit 54 may also take into account the detection result by the tension sensor 17 when acquiring the rotation speed command value. In other words, the roller control unit 54 may finally calculate (generate) the rotation speed command value of the feed roller 41 (more precisely, the torque command value of the roller drive motor 42) based on the above-mentioned rotation speed command value and the detection result by the tension sensor 17. This makes it possible to suppress tension fluctuations caused by disturbance factors other than the reciprocating movement of the traverse guide 33.

As described above, rotation speed adjustment information corresponding to a certain time t1 is acquired in association with predicted information corresponding to time t2, a predetermined time dt after time t1 (i.e., a predetermined time dt in the future). This allows the roller control unit 54 to output a signal related to the rotation speed adjustment (tension adjustment) to be performed at time t2 a predetermined time dt earlier than time t2. This makes it possible to compensate for the delay and adjust the tension at an appropriate timing. Therefore, the tension fluctuation caused by the reciprocating movement of the traverse guide 33 can be effectively suppressed.

In addition, the predetermined time dt is short, less than the reciprocating period of the traverse guide 33. This makes it possible to suppress an increase in the error between the predicted position of the traverse guide 33 corresponding to time t2, which is predicted at time t1, and the actual position of the traverse guide 33 at time t2. Therefore, the tension can be controlled with high precision.

In addition, by acquiring rotation speed adjustment information based on the detection results of the tension sensor 17, feedback control can be performed so that the tension approaches a predetermined target value. Therefore, tension fluctuations caused by disturbance factors other than the reciprocating movement of the traverse guide 33 can also be suppressed, making it possible to further stabilize the tension.

In addition, in this embodiment, tension is controlled by controlling the yarn feed speed by the yarn feed unit 14. Therefore, control can be simplified compared to when the winding unit 13 is controlled to control tension.

Next, we will explain modified versions of the above embodiment. However, parts that have the same configuration as the above embodiment will be given the same reference numerals and their explanations will be omitted as appropriate.

(1) In the above embodiment, the roller control unit 54 calculates the rotation speed command value of the feed roller 41 using a function based on the prediction information, but this is not limited to this. For example, a table in which time, a rotation speed command value corresponding to time t1, and information on a predicted position and/or a predicted speed corresponding to time t2 are associated may be stored in the storage unit 51. As a specific example, the rotation speed adjustment information corresponding to time t1 may be a rotation speed command value (i.e., n2) associated with a predicted position x2 and a predicted speed v2 corresponding to time t2 (see FIG. 8). The roller control unit 54 may obtain such information from the storage unit 51 and control the yarn sending unit 14. Such control is also included in the control in which "information on the rotation speed command value corresponding to time t1 is obtained in association with prediction information corresponding to time t2".

(2) Alternatively, the information on the rotation speed command value does not necessarily have to be clearly associated with the prediction information by a function, a table, or the like. That is, as the above-mentioned specific example, the actual rotation speed of the feed roller 41 (see the solid line in FIG. 9) must be the largest immediately before the traverse guide 33 reaches the outer end in the traverse direction in the traverse region (time t2 in FIG. 9). On the other hand, the time when the rotation speed command value of the feed roller 41 (see the dashed line in FIG. 9) is the largest is not time t2 but time t1, which is a predetermined time dt before time t2. That is, for example, it is sufficient that the time t1 at which the roller control unit 54 outputs a control signal to the roller drive motor 42 to maximize the rotation speed of the feed roller 41 is earlier than time t2 by a predetermined time dt. Such control is also included in "control in which information on the rotation speed command value corresponding to time t1 is acquired in association with prediction information corresponding to time t2".

(3) In the above embodiment, the rotation speed command value of the feed roller 41 is obtained, for example, by a predetermined function (i.e., the coefficients included in the function are fixed), but this is not limited to the above. For example, the function may have a changeable coefficient. The control device 15 may record information on the rotation speed command value and the detection result by the tension sensor while the winding package Pw is being formed. The control device 15 may perform calculations to update the coefficients based on the recorded information so as to minimize the variation in the tension of the yarn Y. In other words, the control device 15 may be configured to perform learning to obtain an optimal rotation speed command value while the winding package Pw is being formed.

(4) In the above embodiment, the target tension of the yarn Y is constant, but this is not limited thereto. That is, the control device 15 may change the target value of the tension within the reciprocating period of the traverse guide 33. More specifically, as shown in FIG. 10, the target value of the tension when the traverse guide 33 is located at the end of the traverse region in the traverse direction may be set lower than the target value of the tension when the traverse guide 33 is located at the center of the traverse region . This provides the following effects. That is, if the tension of the yarn Y is large when the traverse guide 33 is located at the end of the traverse region in the traverse direction, the yarn Y may be unintentionally pulled inward in the axial direction of the winding bobbin Bw when the traverse guide 33 changes direction. As a result, the amount of yarn Y wound inward in the axial direction of the winding bobbin Bw increases from the target position, and the shape of the winding package Pw may be deformed. In this modified example, the tension when the traverse guide 33 is located at the end of the traverse region in the traverse direction can be reduced. This prevents the yarn Y from being unintentionally pulled inward in the axial direction of the winding bobbin Bw when changing the direction of the traverse guide 33. In this manner, in a configuration in which the target tension value is changed within the reciprocating period of the traverse guide 33, control that suppresses the fluctuation in tension by taking the above-mentioned time lag into consideration is particularly effective.

(5) In the above embodiments, the predetermined time dt is shorter than the reciprocating period of the traverse guide 33, but this is not limited to the above. In other words, if the reciprocating period of the traverse guide 33 is extremely short (if the movement of the traverse guide 33 is extremely fast), the predetermined time dt may be longer than the reciprocating period of the traverse guide 33.

(6) The predetermined time dt may be changed depending on the winding conditions, etc. The predetermined time dt may be constant from the start of formation of the winding package Pw to its completion. Alternatively, the predetermined time dt may be changed as appropriate from the start of formation of the winding package Pw to its completion.

(7) In the above embodiments, the rewinder 1 is equipped with a tension sensor 17, but this is not limited to the above. Even if the tension sensor 17 is not necessarily provided, it is possible to suppress tension fluctuations caused by the reciprocating movement of the traverse guide 33 by using the control described above.

(8) In the above embodiment, the control device 15 controls the tension of the yarn Y by controlling the yarn feed speed, but this is not limited to the above. The control device 15 may also control the tension of the yarn Y by controlling the winding speed.

(9) In the above embodiment, tension is applied to the yarn Y due to the speed difference between the winding speed and the yarn feed speed, but the configuration of the tension applying unit is not limited to this. For example, the rewinder 1 may be equipped with a tension applying device (not shown) having a guide member (not shown) configured to pinch the yarn Y instead of the yarn feed unit 14. In such a configuration, tension is applied to the yarn Y by the frictional force generated when the guide member pinches the yarn. The tension applying device may be configured to change the contact length where the yarn Y comes into contact with the guide member and/or the force with which the guide member pinches the yarn Y. As described above, a tension applying unit may be provided that applies tension to the yarn Y by frictional force instead of the above speed difference.

(10) In the above embodiments, the traverse guide 33 is attached to the endless belt 32, but this is not limited to the above. For example, the traverse guide 33 may be attached to the tip of an arm that is driven to swing (see JP 2007-153554 A, etc.). Alternatively, the traverse guide 33 may be driven to reciprocate by a linear motor or the like.

(11) In the above embodiments, the traverse guide 33 is driven by a drive source configured to be capable of forward and reverse driving, but this is not limited to the above. For example, the rewinder 1 may be equipped with a cam-type traverse device that uses a motor that rotates in one direction as a drive source.

(12) The present invention is not limited to the rewinder 1 and can be applied to various yarn winding machines that wind yarn onto a bobbin.

1. Rewinder (yarn winding machine)
13 Winding section (tension applying section)
14 Yarn sending section (tension applying section)
15 Control device (control unit)
17 Tension sensor (tension detection unit)
23 traverse device 33 traverse guide 53 traverse control unit (prediction information acquisition unit)
54 Roller control unit (tension adjustment unit)
Bw Winding bobbin (bobbin)
dt: predetermined time Y: yarn t1: time (first time)
t2 time (second time)

Claims (6)

A yarn winding machine that winds a running yarn onto a bobbin,
a traverse device having a traverse guide for traversing the yarn along the axial direction of the bobbin;
a tension applying unit that applies tension to the yarn being wound around the bobbin;
A control unit,
The control unit is
a prediction information acquisition unit that acquires prediction information regarding at least one of a future predicted position and a future predicted speed of the traverse guide;
a tension adjustment unit that controls the tension applying unit based on adjustment information related to the adjustment of the tension,
The tension adjustment unit is
a yarn winding machine configured to acquire the adjustment information corresponding to a predetermined first time in association with the prediction information corresponding to a second time that is a predetermined time after the first time. The yarn winding machine according to claim 1, characterized in that the predetermined time is shorter than the reciprocating period of the traverse guide. A tension detection unit is provided to detect the tension applied to the thread,
The yarn winding machine according to claim 1 or 2, wherein the tension adjusting section obtains the adjustment information based on a detection result by the tension detecting section. The tension applying portion is
A winding unit that winds the yarn around the bobbin and a yarn feeding unit that feeds the yarn to the bobbin,
the tension is applied to the yarn by a speed difference between a winding speed at which the yarn is wound around the bobbin by the winding unit and a yarn feeding speed at which the yarn is fed to the bobbin by the yarn feeding unit;
The tension adjustment unit is
The yarn winding machine according to any one of claims 1 to 3, characterized in that the tension is controlled by controlling the yarn feeding section. The control unit is
The yarn winding machine according to any one of claims 1 to 4, characterized in that the target value of the tension is changed within a reciprocating period of the traverse guide. The control unit is
The yarn winding machine according to claim 5, characterized in that, with respect to the traverse direction in which the traverse guide moves, the target value when the traverse guide is located at an end in the traverse area in which the traverse guide moves back and forth is lower than the target value when the traverse guide is located at the center in the traverse area.

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