JPS6347272A - Winder for synthetic fiber thread and winding method - Google Patents

Abstract

PURPOSE:To reduce the generation of bright specks of a fablic obtained using the thread of a thread winding body obtained by controlling the rotating speed of a bobbin shaft via a bobbin shaft driving device so that the rotating speed of a self-driven contact roll is made constant. CONSTITUTION:A winder deceleration-controls a bobbin driving device 26 to make the winding peripheral speed of a thread winding body 9 constant during winding. This deceleration control is performed by detecting the rotating speed of a contact roll 24 and comparing it with the preset target rotating speed. That is, as the winding diameter of the thread winding body 9 is increased, the winding peripheral speed, i.e., the rotating speed of the contact roll 24, is increased, and if it exceeds the target rotating speed, the frequency of a bobbin shaft driving inverter 14 is finely controlled by a command from a control device 15 to decelerate the bobbin shaft driving device 26. As a result, the rotating speed of the contact roll 24 is decreased to the target rotating speed, and the winding peripheral speed is maintained constant.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is useful for thermoplastic synthetic fiber yarn (hereinafter simply referred to as yarn), particularly when the winding speed is 5000 m/min. This invention relates to a winding machine and a winding method.

[Prior art and problems to be solved by the invention] Over the past ten years, many achievements in high-speed manufacturing technology for synthetic fiber yarns have been announced. Among them, the technology of manufacturing yarn with practical physical properties at once by winding the melt-spun yarn into a spool shape without interruption during the spinning process is 4000 m long.
In terms of yield, actual production technology that winds yarn at a take-up speed of 8,000 to 9,000 m/min is attracting attention. The production of synthetic fiber yarn by such high-speed spinning involves spinning the melt-spun yarn into a full volume without going through a drawing process.
The so-called 5-pin take up method involves winding the yarn into a spool as a y oriented yarn, and the so-called 5-pin take up method involves drafting the melt-spun yarn, then drawing it and winding it into the spool.
There is a pin draw take up method.

The 5-pin Take up method is based on US Patent No. 419.50.
51, JP 56-64.133, JP 57-12L613, JP 57-161.12
As disclosed in Japanese Patent Publication No. 0 and Japanese Patent Application Laid-open No. 58-208.416, by spinning and winding fiber yarn at a speed of 7000 m/class or higher, ordinary polyester yarns that cannot be obtained with conventional general-purpose polyester yarns can be obtained. It is attracting attention as a method for producing pressure dyeable yarn.

On the other hand, the 5-pin Draw Take-up method is a technology that attempts to obtain yarn with mechanical properties comparable to those of conventional general-purpose synthetic fibers by high-speed winding.
The technology is introduced in JP-A No. 16,914, Japanese Unexamined Patent Publication No. 140.117/1980, and the like.

On the other hand, as introduced in the Journal of the Japanese Society of Textile Technology Vol. 1.38% 11, there are problems with winding due to higher speeds, such as poor winding of the wound package and occurrence of uneven thread quality in the yarn length direction. , various countermeasures are being considered.

Generally, when winding a cheese-like thread, the thread is traversed by a traverse device and wound onto a bobbin attached to a bobbin shaft via a contact roll. It is well known that the traversed yarn decelerates and reverses itself at both ends of the winding body, resulting in yarn pools at both ends, resulting in a so-called selvedge shape. The high end portion has a slightly larger winding diameter and higher winding hardness than the middle portion of the winding body. The thread body being wound is wound with only the selvage portion being constantly pressed by the rotating contact roll.

The drive systems for this winding include (a) a surface drive system that drives the contact roll, (b) a bobbin shaft drive system that drives the bobbin shaft, and (c) a system that drives the contact roll and the bobbin shaft by interlocking control. In these cases, a contact force acts between the contact roll and the thread body, and frictional transmission occurs on the driven side.

The contact force is the force necessary to transmit the rotational force without causing slip to the driven side and to maintain the thread path of the thread wound around the cheese-shaped thread body.

In high-speed winding, the contact pressure must be particularly large. This contact force acts as a crushing force on the selvage portions of both end faces of the spool due to the contact rolls, which causes end face bulges (hereinafter referred to as bulges) in the spool, resulting in poor winding appearance. be. Furthermore, there is a drawback that uneven thread quality occurs due to the internal stress of the thread that has failed in the thread length cycle between both end faces. Furthermore, during high-speed winding, slippage is likely to occur between the contact roll and the thread body, and winding speed fluctuations are also likely to occur, which causes unevenness in yarn quality to further increase. When weaving and knitting to dyeing are carried out in secondary processing using thread bodies with such filament irregularities, minute luster irregularities on the weaving surface, commonly known as "sink marks", appear. This is such a serious problem in practical use that such woven or knitted fabrics have virtually no commercial value.

In the prior art, various proposals have been made to eliminate these drawbacks. Japanese Patent Publication No. 49-6495 discloses a traverse cam with a special locus to reduce the height of the ear, and Japanese Patent Publication No. 50-22130 and Japanese Patent Application Laid-Open No. 60-167855 disclose a cam for traverse having a special locus for reducing the height of the ear. In order to do this, the traverse trajectory is a special multi-track cam traverse, and Japanese Patent Application Laid-Open No. 56-127558 uses a scroll cam type traverse mechanism with a special trajectory to increase the contact area between the contact roll and the buff cage. JP-A-50-83544 proposes a method of gradually reducing the contact pressure.

However, if these proposals are wound with a conventional friction-driven bobbin shaft drive type winder at a speed of 5,000 m/min or more, the winding shape of the spool will be distorted during winding, making it difficult to wind normally. Therefore, it is difficult to even collect the spools, let alone improve the quality.

On the other hand, Japanese Patent Application Laid-Open No. 52-21438 and US Patent No. 3.
Japanese Patent No. 288,383 discloses, as a method for controlling the winding speed to a constant value, a method in which a change in current consumption of a contact roll drive device is detected to control a bobbin shaft drive device. However, in detecting the current consumption, it changes due to the heat generation of the drive device, changes in the sliding resistance of the bearing, etc., so it is difficult to accurately determine the winding speed, especially in high-speed winding of 5000 ra/min or more, which is the object of the present invention. It is inappropriate to maintain the

In order to solve the above-mentioned problems, Japanese Patent Application Laid-Open No. 60-209013 discloses a method in which a spindle drive type winder is used to wind the spool in the form of a pirn-like spool without contacting other objects. A method is proposed. This proposal suggests that it is extremely difficult to solve filament irregularities, ie, "sink" irregularities, and dye irregularities, using a winding means having high-speed traversing and contact rolls.

Therefore, it is a cheese-shaped yarn wound at a high speed of 5000 m/min or more, has good shape stability, and can eliminate the "sink" defect by directly applying the yarn from the yarn to the knitted fabric. At present, a cheese-like wound body of synthetic fiber yarn that does not produce such a product has not yet been found.

The first object of the present invention is to provide a winding machine and a winding method that can produce synthetic fiber yarn free of sink marks and dye spots at a high spinning speed of 5000 m/min or more. There is a particular thing.

A second object of the present invention is to provide a winding machine and a winding method capable of obtaining a cheese-like thread body with less bulge and edge height on the end face of the thread body.

A third object of the present invention is to provide a winding machine and a winding method that can achieve the first and second objects in accordance with the standards for the use of the yarn. be.

[Means for solving problems]

A winding machine for winding a synthetic fiber yarn at a constant speed for achieving the above-mentioned object of the present invention includes a bobbin shaft on which a synthetic fiber yarn winding bobbin is attached, and a bobbin shaft connected to the bobbin shaft. a bobbin shaft drive device that rotates a shaft; a traverse device that swings the yarn supplied to the yarn winding bobbin; a contact roll disposed so as to be in contact with the surface of the filament being wound; a contact roll drive device connected to the contact roll to rotate the contact roll; and a rotation for detecting the number of rotations of the contact roll. a number detecting device; the detecting device and the bobbin shaft drive device are electrically connected to each other, and the bobbin is connected to the bobbin shaft drive device so that the number of rotations of the contact roll is constant in response to a signal from the detection device; The traversing device in the winding machine is characterized in that it includes a control device for controlling the rotational speed of the shaft, and the traversing device has a spiral endless groove consisting of a plurality of oblique paths and a folded curved path connecting the oblique paths. It is preferable that the cylindrical multi-track cam is provided on the outer periphery, and the turning points of the turning curved path are arranged at different positions with respect to the axial direction of the cylindrical multi-track cam.

Furthermore, the traversing device has a spiral endless groove on the outer periphery consisting of a plurality of diagonal paths and a turned curved path connecting the diagonal paths, and the turning points of the turned curved path are opposite to each other in the axial direction. The bobbin shaft drive comprises cylindrical multi-track cams arranged at different positions, and the bobbin shaft drive supplies the driving force necessary for winding the thread traversed on the bobbin shaft, while the contact roll More preferably, the drive device is configured to supply the contact roll with the driving force necessary for self-rotation of the contact roll.

On the other hand, in the winding method, a bobbin shaft on which a bobbin for winding a synthetic fiber yarn is attached, the axis of which is arranged parallel to the axis of the bobbin shaft, and a yarn body being wound on the bobbin. In a winding method of winding a synthetic fiber yarn at a constant speed using a winding machine comprising a contact coal that rotates while contacting a surface, the yarn is wound on a bobbin shaft drive device connected to the bobbin shaft. In addition to supplying the driving force necessary for winding, the contact roll driving device connected to the contact roll is provided with a drive force that allows the contact roll to reach the target when the bobbin shaft and the contact roll are in a non-contact state before winding. A driving force capable of reaching a rotational speed corresponding to the winding speed is constantly supplied during winding, and the rotational speed of the contact roll is detected, and the bobbin shaft drive device is controlled so that the contact roll has a constant circumferential speed. It is preferable to use a synthetic fiber yarn winding method characterized by winding at a winding speed of 5,000 m/min or more by changing the rotational speed, or to wind the melt-spun yarn at a winding speed of 5,000 m/min or more without stretching or drawing. When winding a cheese-like package using a spindle-driven winding machine for more than a minute, the self-driven contact roll and the traverse of the yarn are reversed in the direction of the bobbin axis of the buff cage from the ends to the center. It is preferable to use a method for winding thermoplastic synthetic fiber yarn, which is characterized by winding using a winding machine equipped with a multi-trunk cam traverse that can form a portion with a higher hardness than that of the thermoplastic synthetic fiber yarn.

The present invention will be described in detail below with reference to the accompanying drawings showing an example of a winder according to the present invention.

FIG. 1 shows that the rotation speed of the bobbin shaft according to the present invention is controlled,
An embodiment of a high-speed spinning take-up device is shown that utilizes a bobbin shaft-driven take-up machine with self-driven contact rolls and a multi-track cam.

The construction of the spinning device in the high speed take-up device shown in FIG. 1 is similar to the construction of the spinning device disclosed in Japanese Patent Application Laid-Open No. 58-208416. As shown in FIG. 1, the polymer is extruded as a filament from a spindle 1 mounted on a uniformly heated spinning head 2.

After the filament is slowly cooled and thinned by the heating cylinder 3, it is cooled and solidified by the cooling air blown out from the duct 6. A plurality of filaments constituting the thread 5 are bundled by an oil supply nozzle 4 and a finishing agent is applied thereto.

The thread 5 further passes through a guide 8 disposed below and is wound by a winder into a thread body 9.

In the winding machine shown in FIG. 1, a bobbin shaft 11 with a bobbin 10 mounted thereon is connected to a bobbin shaft drive device 26 connected to an inverter 14, while a contact roll 24 supported by a bearing is mounted on a contact roll housing (see FIG. A pulley 23 placed on one end of a contact roll 24 (not shown) is driven by a contact roll drive 20 via a belt 22. In this way, the contact roll 24 is rotated by the driving force from the contact roll drive device 20. A contact roll drive impark 25 is connected to the contact roll drive device 20 . A large size 13 used to detect the rotation of the contact roll 24 is arranged at the other end of the contact roll 24, and a non-contact type rotation speed detection device 12 is located close to the contact roll 24 in correspondence with the large sword 13. Placed. This rotation speed detection device 12 is a control device 1 having a built-in circuit for calculating the rotation speed of the bobbin shaft.
5, and the control device 15 is connected to an inverter 14 for driving the bobbin shaft.

a traverse cam 19, i.e. a cylindrical cam supported at both ends by a pair of bearings; and a thread jn whose one end is inserted into a groove of the traverse cam 19 and whose vertical movement is defined by a pair of rails 17. Guide 1
A traverse device 27 comprising a contact roll 2
4 (see Figure 2A). A traverse cam drive device 16 is connected to the traverse cam I9, and the traverse cam drive device 16 is connected to a traverse cam drive inverter (not shown).

2a and 2b show a mechanism for performing orthogonal movement of the contact roll housing 28, which houses the traverse device 27 and the contact roll drive device 20, with respect to the bobbin shaft 10. The contact roll housing 28 cooperates with a lifting base 31 housed in the frame 29 of the winder. That is, the lifting base 31 is connected to the frame 2 of the winding machine via the built-in bearing.
It is slidably held on a slide shaft 30 fixed to the housing 9, and is moved up and down using an air cylinder 32.

FIG. 3 shows the structure of the contact roll 24 in detail. As shown in FIG. 3, shafts 61a, 61b protruding from both ends of contact roll 24 are supported by bearings 33a, 33b in bearing housings 34a, 34b.

Bearing housings 34a, 34b are secured to contact roll housing 28. Bearing covers 35a, 35b serve to retain bearings 33a, 33b in bearing housings 34a, 34b. Pulley 23 connects collar 36 and washer 3
7 is placed on the shaft 61a and fixed by the screw 38. The belt 22 is connected to the pulley 23 and the motor 20.
It is arranged between pulleys 21 fixed above. The rotation speed detecting blade 13 is arranged on the outer circumferential surface of the end portion of the contact roll 24.

FIG. 4 shows a block diagram illustrating the control device 15 of the winding machine. A signal emitted from a non-contact rotation detection device 12 that detects the rotation speed of the contact roll 24 by detecting the holes of the plurality of perforations 13 is input to the pulse counter 71. The pulse counter 71 adds up the number of holes 13 that pass within the measurement time interval issued by the measurement period generator 70. Meanwhile, a train of clock pulses is generated from a reference clock generator 74 on the order of IMB2, and a clock counter 72 accumulates the number of clock pulses within the measurement time interval issued by the measurement period generator 70. The actual number of revolutions of the contact roll 24 is obtained by calculating by the calculator 73 the number of six rows and the number of clock pulses passed during the time interval. A comparator 76 compares the actual rotational speed, ie, the current rotational speed, with the theoretical rotational speed generated by the yarn speed setting device 75 to determine the deviation therebetween. With the deviation thus obtained and the control gain obtained by the gain setting device 78 according to the current rotation speed,
The required control amount is determined via the multiplier 77 and the integrator 79, the bobbin shaft drive frequency is set based on the initial frequency set by the initial yarn speed setting device 82, and the bobbin shaft drive device 26 is driven by the inverter 14. is configured to do so. In addition, the inverter controller 80 sends a signal to the gain setter.
Information on the current bobbin shaft drive frequency is sent, and the current appropriate control gain is set based on this information.

In the winding machine having such a configuration, the bobbin shaft drive device 26 is controlled to reduce the speed in order to keep the winding circumferential speed of the thread body 9 constant during winding. This deceleration control is performed by detecting the rotation speed of the contact roll 24 and comparing it with a set target rotation speed. That is, as the winding diameter of the spool increases, the winding circumferential speed and eventually the rotational speed of the contact roll increase, and when the rotational speed of the contact roll increases and exceeds the target rotational speed, the bobbin shaft drive inverter is immediately controlled by a command from the control device 15. The frequency is controlled and the bobbin shaft drive device 26 is decelerated. As a result, the contact roll 24
The rotational speed decreases to the target rotational speed, and the winding circumferential speed is maintained constant.

In addition, since the contact roll 24 always rotates at a constant rotation speed at a constant winding speed, the contact roll 24
is kept in a non-contact state with the bobbin 10, and the frequency and driving force are adjusted by the contact M roll drive inverter 25 so that the rotation speed of the contact roll 24 can reach the target winding speed. Therefore, it is sufficient to constantly supply this driving force during winding, and there is no need for any particular adjustment.

By making each drive system self-driven in this way, the winding machine according to the present invention differs from conventional winding machines in that the bobbin shaft drive device 26 controls the windings wound around the bobbin shaft 11 and the bobbin 10. The receiver has the driving force necessary for winding, including the rotational power of the yarn body 9 and the force for taking up the yarn, and the contact roll drive device is necessary for rotating the contact roll 24 via the transmission devices 21, 22 and 23. The receiver has a strong driving force, and when winding the yarn 5 at a constant winding speed, it is possible to minimize the rotational transmission force between the winding body 9 and the contact roll 24. .

FIG. 7 shows the relationship between the circumferential speed of the contact roll during winding and the circumferential winding speed of the thread body in the winding machine according to the present invention. As shown in FIG.
4, the thread is wound onto the thread body 9 at a winding circumferential speed v2. A constant winding speed according to the present invention means that the relationship of set peripheral speed - contact roll peripheral speed (V+) = winding peripheral speed (■2) is established, and the winding speed during winding is Ideally, there should be no change in

However, U.S. Pat.
In the conventional concept of driving force distribution and winding speed detection method as disclosed in No. 288383, especially in the case of high-speed winding, as mentioned above, there is a permanent gap between the contact roll and the winding body. A slight slip occurred, and the positive circumferential speed of the contact roll could not be detected.

In the winding machine of the present invention, by eliminating the rotational force transmitted between the contact roll 24 and the winding body 9, the above-mentioned slip is minimized, and the contact roll circumferential speed V, = winding circumferential speed v2, is achieved. By directly detecting the circumferential speed of the contact roll, that is, the rotational speed of the contact roll 24, it has become possible to wind at a constant winding speed.

An embodiment of a device for detecting the rotational speed of the contact roll 24 is shown in FIG. In this embodiment, a plurality of rows 13 of holes are arranged on the outer circumferential surface of the contact roll 24. Furthermore, as shown in FIGS. 15a and 15b, the shaft of the contact roll 24 is
A disk 51 attached to the disk 2 and having a circular row of holes 52 and a detector 53 detecting the presence of the holes 52 may be used as the rotational speed sensing device. This photoelectric sensor or magnetic sensor may be used as the detector 53. Marks, protrusions, colored spots or grooves which are equiangularly arranged on the end surface of the disc and which can be detected by a detector can be used instead of the holes.

In the embodiment shown in FIG. 4, a reference clock is generated in parallel with the integration of the number of detection holes in the object to be detected, and a more accurate current rotation speed is determined from both counts. Even if the detection system was configured without the counting system, the accuracy would drop slightly, but it would be sufficient for practical use.

In the embodiment shown in FIG. 4, the detection system was constructed using a digital system, but good control performance was also obtained when controlled by an analog detection system.

The strength of the rollers constituting the contact rolls, especially local stress concentration, reaches a problem area at a winding speed of 7,000 m/preparation.
igh Tenacity saw wood should be utilized.

Incidentally, at a winding speed of 10,000 m 2 /min, a centrifugal stress of about 20 kg/m 2 will be applied.

Also, regarding the diameter of the roller, energy consumption increases depending on its surface area, for example, φ100X 800f
When the roller is rotated at 10,000 m/min,
The power consumption is approximately 3.8Kw, and the smaller the diameter the better, but this also increases the rotational speed of the roller (10,000m/min x φ100 roller, the rotational speed is 32,000r , pom)) There is a concern about the impact on bearing life, and it is preferable to use φ80~
It is better to configure the diameter within the range of φ120.

In addition, in the case of bearing lubrication, the DN value far exceeds the appropriate value for normal grease lubrication, and oil mist lubrication should preferably be used. Adopts mist lubrication method.

The contact roll drive 20 of the present invention preferably uses a high speed three phase induction motor. The connection method of this motor is not limited to the embodiment, and it may be directly connected to the shaft of the contact roll, or it may be built into the contact roll and implemented as an outer rotor type. Furthermore, it can also be driven by an air turbine without using a motor.

Also, a contact roll drive device 20 connected to the contact roll 24
If there is no uncertain speed difference (for example, slip during belt transmission) between the contact roll 24 and the contact roll 24, the rotation speed of the contact roll drive device 20 is detected, and the contact roll 2
4 rotation speed may be detected.

Furthermore, since the above-mentioned contact roll rotation speed detection device does not have any mechanical contact parts, it is not safe or reliable when using the contact roll of a high-speed winding machine that operates at far more than 10,000 revolutions per minute. Very expensive. Incidentally, according to the embodiment of the present invention, even when the winding speed was 7,000 m/min or more, a rotation accuracy of ±0.1% or less could be achieved.

The driving force supplied to drive the contact roll is such that the desired winding speed is the same as the circumferential speed of the contact roll, which is measured with the contact roll not in contact with the bobbin shaft without winding. If the corresponding driving force is 100%, then 75% to 12
If it is 5%, the purpose of the present invention can be sufficiently achieved. Usually 10
0% will be accepted.

(Hereinafter, 100% is shown unless specified.) However, the frequency for the contact roll is preferably set in a range from 0 to 10% higher than the calculated frequency corresponding to the set winding speed.

FIG. 9 shows the winding shape of the spool 9 wound by the winding machine of the present invention, and the case of FIG. 8 showing the winding shape of the spool 9 wound by the conventional winding machine. In comparison, a good winding shape with small bulges was obtained even with the same edge angle.

Furthermore, conventionally, the winding machine generally has a winding angle set in a range of 5 to 7 degrees, and the lower the winding angle, the more the bulge appears. However, if the present invention is applied, it is possible to reduce the bulge and obtain a good winding shape even at the lower limit of the wind angle range mentioned above, and depending on conditions, winding of 5° or less is also possible.

Therefore, by utilizing the above effect, it is possible to reduce the traverse speed by lowering the traverse angle, thereby reducing the increase in yarn tension at the traverse reversal section, and by reducing the speed of the traverse device. It is also possible to extend the service life (particularly effective on the guide life of the cam traverse device) and to improve the quality of the thread as it reduces tension fluctuations.

Furthermore, in the winding method according to the present invention, the winding body 9 and the contact roll 24 are individually supplied with the driving force necessary for the target winding speed to the bobbin shaft 11 and the contact roll 24.
By eliminating the reaction force a (see FIG. 6) of the rotational transmission force between the ends, it is now possible to obtain a good wound spool 3 without end face bulges. Regarding the contact force b (see Fig. 6), the contact force necessary to obtain the rotational transmission force between the winding body 9 and the contact roll 24 can be omitted, and at least the contact force b (see Fig. 6) can be made unnecessary for the cheese-shaped winding body. It is now possible to apply only a small contact force necessary to maintain the thread path of the thread to be wound.

Next, the multi-track cam type traverse device and winding method of the present invention will be explained.

The cylindrical multi-track cam type traverse device used in the winder according to the present invention shown in FIG. It consists of a guide rail 17, a thread guide 18 that fits into the guide groove and is guided in the axial direction by the guide rail and makes reciprocating motion, a traverse drive device 16, and a traverse drive inverter (not shown). By setting the frequency of the traverse drive inverter to the required number of traverses, the cylindrical cam 19 is rotated, and the yarn guide 18 is operated to traverse the yarn 5.

A multi-track cam, which is one of the main parts of the present invention, is used as the cylindrical cam 19. The multi-track cam itself is disclosed in Japanese Patent Publication No. 50-22130 and Japanese Patent Application Laid-Open No. 60-60.
Although it is publicly known as disclosed in detail in Japanese Patent No. 167855, etc., the multi-track cam used in the yarn winding machine according to the present invention is shown in FIGS. 10, 11a and 11.
This will be explained below with reference to figure b.

The cam groove A as shown in FIG. 10 starts from an arbitrary starting point, for example, the first turning point R1, continues from ■-■-■, reaches the second turning point R2, and further passes from ■ to ■. The vehicle reaches the third turning point R1 and forms the first round trip L1. Furthermore, from ■ to 0, return to the starting point, the first turning point R1,
L2 is formed during the second round trip. In other words, it has a 2-track multi-trunk cam groove. In the first round trip 11L, the second and third turning points are 11.

There is a shortening width of 12 turns, which is narrower than L2 during the second round trip. That is, on the outer peripheral surface of the cylindrical cam 19 of the traversing device used in the present invention, a plurality of oblique paths shown, for example, by ■-■ or ■-[phase] in FIG. A spiral endless groove consisting of a folded curved path indicated by ■-■ or ■-@ is provided, and the turning point of the folded curved path (R+, R2 in FIG. 10)
, Rx and R4) are arranged at different positions with respect to the axial direction of the cylindrical cam 19.

FIG. 11a shows the locus of action when the traverse guide is reciprocated by the cam groove in FIG. Form a spool.

Therefore, in the case of this example, there is no thread accumulation at the ears! , ·12.

FIG. 11b shows the operating locus of the three-track cam embodiment, and thus three combinations of L+ < L2 < L3 or two combinations of L+ < Lz = L3 are also possible. Practically speaking, the number of reciprocating passes is preferably 2 to 4. The folding shortening width = 11 to 14 can be set arbitrarily, but the results of experiments conducted by the present inventors have confirmed that setting in>'1 m has the effect of dispersing yarn accumulation at the end face. , was able to accomplish the task.

Next, with reference to FIGS. 13a and 13b, the effect of dispersing yarn pools produced by using a multi-track cam will be explained.

As shown in Figure 13b, the speed of the yarn in the axial direction of the spool is reduced when the yarn is reversed, so that more yarn accumulates at the ends of the spool than in the center; As a result, high ears are produced.

In other words, the amount of yarn produced by the reversal movement of the yarn is denoted by α,
When the amount of yarn produced by normal movement of the yarn is denoted by β, the amount of yarn α−←β is formed within the range of β shown in FIG. 13b. This is the thread pool in a normal thread package. FIG. 13a shows a spool of a spool formed using the two-track multi-track cam shown in FIG. 11a.

In this case, the end of the spool as indicated by reference numeral 41! Within the range of the part that is closer to the inside from the end of the spool body! The yarn amount -+β accumulates within the range of . As can be seen from the above explanation, since the amount of yarn in the thread pool 42 is -+β, the thread pool 42 is equal to the thread pool 4.
formed as a ridge having a hardness higher than 1;
In this way, the ear heights are dispersed.

However, the purpose of the present invention cannot be achieved using such a multi-track cam alone. In other words, the above-mentioned multi-track cam is used to form a bulge with higher hardness at a position of 2 mm or more toward the center of the cheese-shaped spool from the axial end of the spool, compared to the conventional contact structure. When the winding speed was 5,000 m/min or more using a thread winder (friction drive type) having rolls, the above-mentioned 12a.
As shown in the figure, both ends of the spool collapsed during winding, making normal winding impossible.

That is, by combining the above-mentioned self-rotating contact roll and multi-track cam, it is possible to normally wind the film without causing collapse of both ends as shown in FIG. 12b. This is because the reaction force a shown in FIG. 6 can be eliminated.

In this way, the combination of dispersion of the selvage area by the multi-track cam and the self-driven contact roll allows the winding body to be formed in a good shape, and at the same time to prevent uneven yarn quality, dyeing spots, and ``sink'' in the fabric in the yarn length direction. ” can be obtained.

〔Example〕

The present invention will be described in detail below using seven experimental groups (A to G) as follows to clearly illustrate various aspects of the present invention. Note that the definition of each characteristic value used in the examples and its evaluation method are as follows.

◎ Winding shape The bulge (W) shown in FIG. 8 is shown as the bulge ratio (W%).

It is desirable that the bulge ratio (W%) is 10% or less (good), and 5% or less is good (best).
It is evaluated that

■HARDNE made by Shimadzu with a needle diameter of 1.5■■φ in the hardness pressing part
Hardness was measured using SSTESTER (for fibers) by pressing the needle of the pressing part directly against the pan cage. The hardness was measured at eight equally divided positions in the circumferential direction of the package, and the average value of n=8 was determined.

■As a method for measuring the dyeability of dyed yarns, the Journal of the Japanese Society of Textile Technology Vol. 3
The staining spots were measured by the method introduced in 3.Kai 9 (1977). .

Using FYL-600 manufactured by Toshi ■, staining and measurement of staining spots were carried out under the following conditions.

Yarn running speed 30m/min Scouring temperature 60°C1 Scouring time 15 seconds Dyeing temperature 60
'c, Staining time: 80 seconds Measurement sensitivity: 1■ The reason why the staining temperature was set at 60°C is that staining spots can be detected best.

The staining spots are expressed by the variance value (VryJ), which is obtained by statistically processing the fluctuation of the dyeing rate in the yarn length direction. The smaller VFj'L means the fewer the staining spots.
It is desirable that ryt is 0.15 or less (good)
, 0.10 or less is best.

◎ Dry heat shrinkage stress value It is known that the stress in a filament kept at a constant length reaches its maximum value during the heating process due to temperature changes.

(Refer to the Journal of the Textile Society of Japan Vol. 27, m8 1971) The measuring device was a thermal stress measuring device KE- manufactured by Kanebo Engineering Co., Ltd.
Type 2 was used. 5cm with sample length 10c+n as a loop
After applying an initial load of 10 mg/d, the internal temperature of the heating furnace was raised at a heating rate of 150° C./min under a constant length, and a dry heat shrinkage stress curve was drawn. From this curve, the maximum stress value (the value obtained by dividing the read value by the sample denier x 2) was determined and used as the dry heat shrinkage stress value (Fig/d).

The difference in dry heat shrinkage stress value of the filamentous Pa.7 cage was measured as follows. Measure the dry heat shrinkage stress value sequentially in one traverse direction (from one end to the other end), making sure to include the yarn in the part showing the maximum hardness in the longitudinal axis direction of the puff cage. Using this method, measurements were taken for 5 traverses. The distribution of the measured dry heat shrinkage stress values in the longitudinal axis direction of the package corresponds to the hardness distribution, and tends to increase in the order of maximum hardness, both ends, and the center.

The difference in dry heat shrinkage stress value is the average value F + mg/d of the dry heat shrinkage stress value of the yarn in the part showing the maximum hardness and the average value F2mg/a of the dry heat shrinkage stress value of the yarn in the center part. It was calculated from the following formula.

Dry heat shrinkage stress value difference (ΔF)=Fl2Fz (mg/
d) ■ Indication of "sink mark" A skilled inspector will follow empirically determined inspection standards.
The level of defects caused by "sink marks" was classified into four levels and displayed based on visual sensory values.

No sink marks at all W = 1 Very subtle sink marks W = 2 Sink marks W = 3 Strong sink marks The inspection was conducted by three inspectors, and the following judgments were made based on the average value.

W = Best w = O ~ 1 better W = l ~ 2 good W = 2 ~ 3 bad ■ Birefringence Δn Green light vA was determined by the interference fringe method using a transmission quantitative interference microscope (manufactured by Carl Zeiss Jena, East Germany). (Wavelength 54
9 mμ), the refractive index nl+ parallel to the fiber axis and the refractive index n perpendicular to the fiber axis were measured, and the birefringence Δn=n+, -n was determined.

■ Crystal Perfection Parameter OR Using an X-ray diffractometer, a diffraction intensity curve from 2θ of 7° to 35° was drawn under the following conditions, with the sample thickness of the raw thread being 0.5×.

3QkV, 80 Pass, scanning speed 1°/min, chart speed Iom/min, time constant 1 second, receiving slit 0.3 dragon.

Three main reflections drawn in the range of 2θ = 17° to 26° from the low angle side (100), (010), (11
0). The diffraction intensity curves between 2θ-7″ and 35° are connected with a straight line and used as the baseline. Draw a perpendicular line between each peak and the baseline and use this perpendicular line as the diffraction intensity. (01
When the diffraction intensity at a point corresponding to the valley between 0) and (110) is set at 1° and the diffraction intensity at the peak of (110) is set to 1, the crystal perfection parameter C1l is expressed by the following equation.

1゜CR=□ ◎ Sample length under load with spring water shrinkage rate of 0.1g/d. After binding, removing the load, and processing in spring water for 30 minutes, when L is the length measured under the same load, the spring water shrinkage rate is expressed by the following formula.

・The dyeable polyester yarn is dyed with disperse dye Resolin Blue (Re
Solin Blue) FBL (trade name of Bayer) was used, 3% owf, 1:10 at a bath ratio of 1:50.
The dyeing rate was calculated by dyeing at 0°C and 120°C for minutes and measuring the absorbance of the dye solution after dyeing. When the dyeing rate is 60% or more, the dyeing property is good, and when the dyeing rate is 70% or more, it is possible to dye under normal pressure, which is extremely good.

Experimental Group A This experimental group A is a comparative example of the present invention, and shows an example of high-speed winding using a conventional bobbin shaft-driven winding machine with a driven type contact roll.

Spinneret with pore diameter 0.23n and number of holes 2.4, length 30cm
Using a spinning machine as shown in Fig. 1 equipped with a heating cylinder of Polyethylene terephthalate was melt-spun at a spinning speed of 7.000 rn/min to obtain a 75 denier/36 filament polyethylene terephthalate fiber. The temperature of the spinning head is 300'C1 The temperature inside the heating cylinder (heating area temperature) is 250℃
And so. The position of the oil supply nozzle guide was set to be 25 cm below the thinning completion point at any spinning speed.

A conventional winder (FIG. 5) equipped with a contact roll without self-driving force (referred to as a shaft-powered contact roll) was used.

The winding shape of the obtained yarn body when the contact pressure during winding was varied, the staining spots on the surface layer of the 10 kg wound puff cage, and the selvedge area (
Table 1 shows the dry heat shrinkage stress deviations of the yarns at both ends) and the center.

Other conditions during winding are as follows.

Bobbin outer diameter: 140 mmφ, bobbin length 210 m Traverse stroke: 160 mm Winding tension: 0.25 g/d Winding winding angle: 6° Winding contact pressure: 0.25 kg/package stroke 1 cI
11 Next, from these pancages, the entire amount of yarn was directly passed through a Nissan Water Jet Loom (LW) as a weft.
-51 type) for weaving, with a warp density of 100 pieces/in.
A plain woven fabric with a weft density of 80 threads/in was used.

After scouring and presetting, this plain woven fabric was dyed at 130'C, and the quality of weft "sink marks" was determined.

The weft "sink mark" quality of this plain fabric is shown in Table 1.

Table 1 As is clear from Table 1, the conventional bobbin shaft drive winder with a driven type contact hole requires high contact pressure for high-speed winding.
The resulting cheese-like package was unsatisfactory in terms of roll appearance, mass, and lateral "sink marks."

Experimental Group B This experimental group B shows an example of high-speed winding using a bobbin shaft-driven winding machine having a self-driven contact roll with rotational speed control according to the present invention.

Using polyethylene terephthalate with intrinsic viscosity [η) = 0.61, it was extruded at 295°C, heated to a cylinder length of 30cm, and spun at 250°C inside the cylinder, and after cooling, 20° below the thinning completion point.
Gather all the filaments at the position of ■, lubricate and 75'/3
A 6' yarn was wound at different spinning and winding speeds as shown in Table 2.

When winding, a winder equipped with a self-driving contact roll with rotation speed control as shown in Fig. 1 is used, and a contact pressure of 0.12 kg/
The test was carried out under the condition that the winding body stroke was 1 cm.

Other conditions during winding are as follows.

Bobbin outer diameter: 140mmφ, bobbin length: 210n Traverse stroke: 160m Winding winding angle: Winding shape, cluster, and dry heat absorption stress of the ears (both ends) and the center yarn of a 10kg cheese-like package wound at 6° Table 2 shows the deviation and the "sink marks" when fabricated.

Table 2 As shown in Table 2, as a result of using the winding machine equipped with the rotational speed controlled self-driving contact roll of the present invention, the cheese-like package has an extremely excellent winding shape and mass even during high-speed winding. was obtained, and an improvement was also obtained in terms of latitude "sink marks". This effect was observed everywhere from the outer layer to the inner layer of the pancage.

Experimental Group C This experimental group C shows an example of low contact pressure winding using a bobbin shaft-driven winding machine having a self-driven contact roll with rotational speed control.

In the same winding as in experimental group B, the winding speed was set to 700.
0 m/min, and the contact pressure during winding was varied as shown in Table 3 to obtain a winding amount of 10 and a pa-no-cage of +r.

Table 3 shows the result of the winding shape of the obtained package, the group, the dry heat shrinkage stress value difference between the end and center yarns of the 10 kg winding surface layer, and the weft "sink mark".

Table 3 As is clear from Table 3, as a result of using the bobbin shaft-driven winding machine having the self-driven contact roll of the rotation speed control system of the present invention, the contact roll was so low that it could not have been predicted using the prior art. Excellent winding was achieved even at high speed winding of 7,000 m/min, and a cheese-like package with improved winding shape, mass, and weft "sink mark" was obtained.

Experimental Group D This Experimental Group D is an example of high-speed winding using a bobbin shaft-driven winding machine with a rotation speed control type self-driven contact roll equipped with a multi-track cam type traverse device as a traversing device, and the results obtained. This figure shows an example of a cheese-like package.

Polyethylene terephthalate with intrinsic viscosity [η) = 0.60 was extruded at 295°C, heating cylinder length 30cn+, cylinder interior 2
Spun at 50°C, after cooling, all the filaments were bundled at a position 20cm below the point at which thinning was completed, oiled, and turned into 75'/36' yarn by a winder at a speed of 7000 m/min without drawing. A cheese-like package with a winding weight of 10 kg was obtained. The physical properties of the yarn are strength 4.2g/d and elongation 4.
It was 0%.

When winding, a bobbin shaft-driven winding machine equipped with a rotation speed controlled self-driven contact roll shown in Fig. 1 is used.
A winding machine equipped with a three-trunk traverse type cam traverse as shown in Fig. 1b was used.

The trajectory of the traverse is Ll <Ll =L in Figure 11b.
3, change the position of the turning point, and change the interval between the turning points (N
, = 12) was carried out as shown in Table 4.

Other conditions in this experiment, Gleep D, are as follows.

Bobbin outer diameter: 140maφ, bobbin length: 21O
n Traverse stroke: I60 1 Winding tension: 0.25 g/d Winding contact pressure: 0.25 kg/package 1 stroke length Winding winding angle: 6° Table 4 shows the winding form of the package obtained, 10 kg winding The difference in dry heat shrinkage stress value between the raised part and the yarn in the center of the package surface layer and the weft "sink mark" quality of the plain fabric obtained by using the entire amount as the weft are shown.

As is clear from Table 4, the cheese-like package obtained by the bobbin shaft-driven winding machine equipped with the multi-trunk traverse, which is the traversing device of the present invention, and equipped with a self-driving contact roll of the rotation speed control type, is It is an excellent product that eliminates the problems of conventional products in terms of appearance, grouping, and lattice "sink marks." Note that this effect is achieved in all parts of the package, from the outer layer to the inner layer.

On the other hand, as a comparative example corresponding to experimental group D, the fifth
Winding was attempted using a bobbin-driven winding machine equipped with a conventional driven contact roll that does not have self-driving force as shown in the figure, and a winding machine equipped with a similar three-track traverse.

The distance between the reversal positions of the traverse (l+ = 1z) is 3 m.
Winding was carried out for two types, 5 m and 5 m, but the shape collapsed from the time when about 0.5 kg of yarn was laminated from the beginning of winding, and it was difficult to continue winding.

Experimental Group E This experimental group E shows the effect of contact pressure during winding in Example 4.

In carrying out the 10th example in experimental group D,
Winding was carried out by varying the contact pressure during winding as shown in Table 5. The rolled form of the obtained cheese-like package, the difference in dry heat shrinkage stress value between the threads in the raised part and the central part, and the weft "sink mark" quality are shown.

As is clear from Table 5, a multi-track cam type traverse device was installed as the traverse device. As a result of using a bobbin shaft-driven winding machine with a rotation speed control type self-driven contact roll, it is possible to wind up the cheese-shaped package of the present invention with low contact pressure, which was impossible even to take out the pancage with a conventional winding machine. It has become possible.

Furthermore, the obtained cheese-like package has improved roll shape, mass, and weft "sink marks" and has high commercial value.

The effects of the present invention were confirmed in all parts of the package, from the outer layer to the inner layer.

Experimental Group F This experimental group F shows a polyester yarn cheese-like pancage that can be dyed under normal pressure and is free from the "sink mark" defect, which can be obtained by high-speed 5-pin take up.

Spinneret with pore diameter 0.23 and number of holes 2.4, length 30 cfa
Using a spinning machine as shown in Fig. 1 equipped with a heating cylinder of Polyethylene terephthalate was melt-spun at 300°C, and after cooling, all the filaments were bundled at a position 20 cm below the thinning completion point, oiled, and spun as 75'/36' yarn without drawing at the speeds shown in Table 6. Winding is done with a winding amount of 12k.
A cheese-like package of g was obtained.

The temperature inside the heating cylinder (heating zone temperature) was 250°C.

For winding, a winder was used which was equipped with a rotation speed controlled self-driven contact roll shown in FIG. 1 and a two-trunk traverse type cam traverse shown in FIG. 11a.

The trajectory of the traverse is shown in Fig. 11a, and β1-22=4 dragons were adopted.

Other conditions were the same as in Example 4 to obtain a puff cage.

The positions of the convex portions of the obtained cheese-like packages from the ends were all 5 cm (m, -m2), and the shape stability during winding was also good.

The physical properties of the obtained yarn, the shape of the 12 kg package, the difference in dry heat shrinkage stress value (ΔF) between the raised part of the surface layer part and the yarn of the central part, and the woven fabric obtained in the same manner as in Experimental Group A. Table 6 shows the "sink mark" quality.

As is clear from Table 6, polyester yarn packages obtained at spinning speeds of 6,000 m/min or higher (
22) In addition to having a good winding shape, the fabric obtained by directly applying it to the weft of a fabric had good dyeability when dyed under normal pressure and good quality without weft "sink marks." .

Experimental Group G This experimental group G shows an example of polycaproamide yarn pancage as the synthetic fiber yarn.

Polycaproamide with a relative viscosity of 2.4 measured with 95% sulfuric acid was melt-spun at 270°C, and after cooling, a pair of unheated godet rolls was used to set the circumferential speed of both rolls to be the same, and the polycaproamide was spun at 50'/min without stretching. As No. 17', winding was performed at the speed shown in Table 7 to obtain a cheese-like package weighing 1 8 kg.

Winding is carried out using a bobbin shaft-driven winding machine equipped with a rotation speed controlled self-driven contact roll as shown in Fig. 1, and also equipped with a three-track traverse type cam traverse as shown in Fig. 11b. A removing machine was used. The trajectory of the traverse is
In Figure 11b, let L l< L t=L, and N,=β2
= Adopted the 3 crane mechanism.

In this experimental group G, the following conditions were used except that the winding contact pressure was 0.15 kg/package stroke 1 cm.

Bobbin outer diameter: 14 (hlφ Traverse stroke: 160 nm Winding tension: 0.
25 g/d Winding winding angle: 6° The shape stability during winding was good in all cases, and the position ii2 (L - 12') from the end of the raised part of the pan cage was 4.
From the resulting package, use ordinary polycaproamide yarn as the warp, and use it as the weft directly from the polycaproamide yarn pancage wound by the above-mentioned winding method,
A plain woven fabric was prepared with a weft density variation of 105 yarns/in. After scouring and presetting, the weft "sink mark" quality of the fabrics dyed at 100°C was determined.

Table 7 shows the characteristics of the package and the corresponding quality of the "sink mark".

Table 7 As is clear from Table 7, the polyamide yarn cheese-like package obtained by the present invention has a good winding appearance even during high-speed winding and a fabric of good quality even after weaving. Ta.

〔Effect of the invention〕

The winding machine according to the present invention uses a self-driven contact roll and is configured to control the rotation speed of the bobbin shaft via a bobbin shaft drive device so that the rotation speed of the contact roll is constant. It is possible to reduce the occurrence of weft sink marks in a fabric obtained using the yarn of the obtained yarn body. By using a cylindrical multi-track cam in the traversing device of the yarn winding machine, a wound body having a good winding appearance can be formed.

If the above-mentioned winding machine is used, high-speed spinning of 5,000 m for 7 minutes or more can be performed, and even if the spool is directly made, a spool with no defects such as weft sink marks and a good winding appearance can be produced. Can be done. Particularly, it exhibits remarkable effects in high-speed spinning of 7,000 m and 7 minutes or more.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing an embodiment of a high-speed spinning take-up device having a take-up machine according to the present invention, and FIG. 2a is a partially cutaway view of the take-up machine in the device shown in FIG. It is a front view, and the second
Figure b is a partially cutaway side view of the winder in Figure 2a;
5 is a detailed side view of the contact roll used in the winder shown in FIG. 1, FIG. 4 is a block diagram showing an embodiment of the control system for the winder according to the present invention, and FIG. 6 is a side view of a conventionally known winding machine for synthetic fibers, FIG. 6 is a diagram illustrating the force acting on the yarn during the formation of a wound body in the conventionally known winding machine, and FIG. 8 is a diagram illustrating the force acting on the yarn during formation of a spool in the winding machine according to the present invention, FIG. 8 is a partial cross-sectional view of a conventionally known spool, and FIG. FIG. 3 is a partial cross-sectional view of a spool according to the invention;
FIG. 10 is an exploded view of a traverse cam with multi-track grooves used in the winder shown in FIG. 1, and FIG. FIG. 11b is a diagram similar to FIG. 11a showing another embodiment of the groove trajectory, and FIG. 12a is a diagram showing the groove trajectory in a state of contact with a contact roll. FIG. 12b is a side view of a spool wound by a conventionally known winding machine, and FIG. 12b is a side view similar to FIG. 11a showing a spool wound by a winding machine according to the present invention. , 13th
FIG. 13a is a diagram illustrating the occurrence of thread accumulation in the thread body shown in FIG. 12b, FIG. 13b is a diagram explaining the occurrence of thread accumulation in the conventionally known thread body, and The figure is a sectional view showing an embodiment of a multi-hole type rotation speed detecting device used in a winder according to the present invention, and FIG. FIG. 15b is a front view showing an embodiment of the disc of the detection device;
The figure is a side view showing the relationship between the disk and the detection device shown in FIG. 15a. 5... Thread, 9... Thread body, 10...
・Bobbin, 12... Rotation speed detection device, 13.
... Hole hole, 14... Bobbin shaft drive inverter, 15... Control device, 18... Thread path guide, 19... Traverse cam, 20... Contact roll drive device, 24... Contact roll, 25... Inverter for driving the contact roll.

Claims (1)

[Scope of Claims] 1. A bobbin shaft on which a synthetic fiber yarn winding bobbin is mounted, a bobbin shaft drive device connected to the bobbin shaft to rotate the bobbin shaft, and a bobbin shaft drive device connected to the bobbin shaft for rotating the bobbin shaft; A traversing device for traversing the supplied yarn, the axis of which is arranged parallel to the axis of the bobbin shaft and is arranged so as to be in contact with the surface of the yarn body being wound on the bobbin. A contact roll, a contact roll drive device connected to the contact roll to rotate the contact roll, a rotation speed detection device for detecting the rotation speed of the contact roll, and an electrical connection between the detection device and the bobbin shaft drive device. The present invention is characterized by comprising a control device which is connected to the device and controls the rotation speed of the bobbin shaft via a bobbin shaft drive device so that the rotation speed of the contact roll is constant in response to a signal from the detection device. A winding machine that winds synthetic fiber yarn at a constant speed. 2. The traversing device has a spiral endless groove on the outer periphery consisting of a plurality of diagonal paths and a turned curved path connecting the diagonal paths, and the turning points of the turned curved path are opposite to each other in the axial direction. Winding machine according to claim 1, characterized in that it comprises cylindrical multitrack cams arranged at different positions. 3. The traversing device has a spiral endless groove on the outer periphery consisting of a plurality of diagonal paths and a turned curved path connecting the diagonal paths, and the turning points of the turned curved path are opposite to each other in the axial direction. comprising cylindrical multi-track cams arranged at different positions; said bobbin shaft drive supplies the driving force necessary for winding the yarn traversed on said bobbin shaft, while said contact roll drive A winder according to claim 1, characterized in that the device is arranged to supply the contact roll with the driving force necessary for self-rotation of the contact roll. 4. A bobbin shaft on which a synthetic fiber yarn winding bobbin is attached, and its axis is arranged parallel to the axis of the bobbin shaft and rotates while contacting the surface of the yarn body being wound on the bobbin. In a winding method of winding a synthetic yarn at a constant speed using a winding machine comprising a contact roll, the driving force necessary for winding the yarn is applied to a bobbin shaft drive device connected to the bobbin shaft. is supplied to the contact roll driving device connected to the contact roll, and the contact roll rotates at a target winding speed when the bobbin shaft and the contact roll are in a non-contact state before winding. A constant supply of driving force that can reach up to several times during winding is performed, and the number of revolutions of the contact roll is detected, and the number of revolutions of the bobbin shaft drive device is changed so that the contact roll has a constant circumferential speed. ,
A method for winding synthetic fiber yarn, characterized by winding at a winding speed of 5000 m/min or more. 5. Without stretching or drawing the melt-spun yarn,
When winding a cheese-like package using a spindle-driven winder at a speed of 5000 m/min or more, the self-driven contact roll and the traverse of the yarn are reversed in the bobbin axis direction of the package from the ends to the center. A method for winding a thermoplastic synthetic fiber yarn, characterized in that winding is carried out using a winding machine equipped with a multi-track cam traverse capable of forming a portion with higher hardness than the end portion.