EP2392531B1

EP2392531B1 - Yarn accumulating device

Info

Publication number: EP2392531B1
Application number: EP11167730.8A
Authority: EP
Inventors: Itaru Yokota; Masaki Oka
Original assignee: Murata Machinery Ltd
Current assignee: Murata Machinery Ltd
Priority date: 2010-06-02
Filing date: 2011-05-26
Publication date: 2015-10-14
Anticipated expiration: 2031-05-26
Also published as: EP2392531A3; CN102267650A; CN102267650B; JP2011251820A; CN202089640U; EP2392531A2

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a yarn accumulating device, and more specifically, to a technique of a yarn accumulating roller of the yarn accumulating device.

2. Description of the Related Art

Conventionally, there is known a spinning machine for spinning spun yarn with a spinning device, and winding the spun yarn by a winding device to produce a package. There is also known a yarn accumulating device for adjusting a winding tension of the spun yarn before the spun yarn spun by the spinning device is wound by the winding device. The yarn accumulating device includes a yarn accumulating roller and a yarn hooking member. The yarn accumulating roller is rotatably driven and winds the spun yarn around an outer peripheral surface thereof to accumulate the spun yarn. The yarn hooking member is axially supported in a relatively rotatable manner on a rotation shaft of the yarn accumulating roller, and guides the spun yarn downstream while making contact with the travelling spun yarn unwound from the yarn accumulating roller.
The travelling spun yarn unwound from the yarn accumulating roller travels while making contact with a flange portion of the yarn accumulating roller. The flange portion is a portion where a diameter increases towards a downstream end side of the yarn accumulating roller in the yarn travelling direction. Japanese Unexamined Patent Publication No. 2006-306588 discloses a yarn accumulating device in which the flange portion of the yarn accumulating roller is formed in a circular shape when viewed from an axial direction of the yarn accumulating roller. Japanese Unexamined Patent Publication No. 2009-173419 discloses a yarn accumulating device in which a position where the travelling spun yarn unwound from the yarn accumulating roller makes contact with the yarn hooking member is changed to lengthen a lifespan of the yarn hooking member with respect to wear caused by the travelling of the spun yarn. This prior art document discloses, as an example of the yarn accumulating device, a yarn accumulating device in which the flange portion of the yarn accumulating roller is formed in an elliptical shape when viewed from an axial direction of the yarn accumulating roller.
Meanwhile, a tension fluctuation caused by an influence of winding at the downstream exists in the spun yarn travelling the flange portion of the yarn accumulating roller. The tension fluctuation causes a contacting pressure between the yarn hooking member and the travelling spun yarn to constantly change at the surface of the yarn hooking member that rotates on the same rotation shaft as the yarn accumulating roller.
In the yarn accumulating roller disclosed in Japanese Unexamined Patent Publication No. 2006-306588 , the flange portion is circular. In such a configuration, the spun yarn travels through the same position on the yarn hooking member while constantly changing the contacting pressure with the yarn hooking member.
In the yarn accumulating roller disclosed in Japanese Unexamined Patent Publication No. 2009-173419 , the flange portion is elliptical. In such a configuration, the spun yarn travels on the yarn hooking member while constantly changing the contacting pressure with the yarn hooking member and while moving in a radial direction. In addition to change in tension (change in contacting pressure), a centrifugal force by a mass of the spun yarn itself acts on the spun yarn travelling on the yarn hooking member. Thus, in the configuration disclosed in this prior art document, the spun yarn does not always travel while making contact with the flange portion of the yarn accumulating roller, and may lift up from the flange portion of the yarn accumulating roller at a short axis portion. If the travelling spun yarn is extremely lifted up from the flange portion of the yarn accumulating roller, the spun yarn may slacken and the spun yarn may enter between the flange portion of the yarn accumulating roller and the yarn hooking member. In this case, the spun yarn may be wound around the rotation shaft of the yarn accumulating roller and a function of the yarn accumulating roller may not be maintained.

BRIEF SUMMARY OF THE INVENTION

It is an object of the present invention to provide a yarn accumulating device for suppressing travelling spun yarn from lifting up from a flange portion of a yarn accumulating roller. This object is achieved by yarn accumulating devices according to claims 1 and 2.
According to a first aspect, a yarn accumulating device includes a roller main body, and a yarn hooking member. The roller main body is adapted to wind spun yarn around an outer peripheral surface thereof by being rotated. The yarn hooking member is attached to a downstream end of the roller main body in a yarn travelling direction. The yarn hooking member is adapted to assist unwinding of the spun yarn from the roller main body by relatively rotating with the roller main body while making contact with the spun yarn. A first flange portion is formed on the roller main body, and a diameter of the first flange portion increases towards the downstream end in the yarn travelling direction. At least a portion of a contour of a projection viewed from an axial direction of the first flange portion is formed as a secondary curvature portion having a smaller curvature than a curvature of an arc of the contour or being completely straight..
A second aspect is the yarn accumulating device of the first aspect, wherein the secondary curvature portion is formed substantially straight.
A third aspect is the yarn accumulating device of the second aspect, wherein the secondary curvature portion is formed at most half of a circumference of the contour.
A fourth aspect is the yarn accumulating device of the second aspect, wherein a total of central angle of the secondary curvature portion is at most 180 degrees.
A fifth aspect is the yarn accumulating device of any of the first to fourth aspects, wherein the contour of the projection viewed from the axial direction of the first flange portion is formed in substantially circular shape, and the secondary curvature portion is formed by cutting the substantially circular shape.
A sixth aspect is the yarn accumulating device of the first to fifth aspects, wherein at least three secondary curvature portions are formed on the contour of the projection viewed from the axial direction of the first flange portion.
A seventh aspect is the yarn accumulating device of the first to sixth aspects, which includes an upstream guide and a downstream guide. The upstream guide is arranged upstream in the yarn travelling direction than an opposite side of the side where the first flange portion of the roller main body is formed, and adapted to guide the spun yarn to the roller main body. The downstream guide is arranged downstream in the yarn travelling direction than the first flange portion of the roller main body, and adapted to guide the yarn unwound from the roller main body.
An eighth aspect is the yarn accumulating device of the first to seventh aspects, wherein the roller main body includes the first flange portion, a second flange portion, and a winding portion. The second flange portion is formed on a side opposite from the side where the first flange portion is formed. The winding portion is formed between the first flange portion and the second flange portion and formed smaller than an outer shape of the first flange portion and an outer shape of the second flange portion, and adapted to wind the spun yarn.
A ninth aspect relates to a spinning machine including the yarn accumulating device of the first to eighth aspects, a spinning device, and a winding device. The spinning device is arranged upstream of the yarn accumulating device in a yarn travelling direction and adapted to produce the spun yarn. The winding device is arranged downstream of the yarn accumulating device in the yarn travelling direction and adapted to wind the spun yarn produced by the spinning device into a package.
According to a tenth aspect, a yarn accumulating device includes a roller main body and a yarn hooking member. The roller main body is adapted to wind spun yarn around an outer peripheral surface thereof by being rotated. The yarn hooking member is mounted to a downstream end of the roller main body in a yarn travelling direction. The yarn hooking member is adapted to assist unwinding of the spun yarn from the roller main body by relatively rotating with the roller main body while making contact with the spun yarn. A first flange portion is formed on the roller main body, and a diameter of the first flange portion increases towards the downstream end in the yarn travelling direction. A straight line portion is formed on at least a portion of a contour of a projection viewed from an axial direction of the first flange portion is formed.
An eleventh aspect is the yarn accumulating device of the tenth aspect, wherein the straight line portion and a curved portion are formed alternately along the contour.
The effects of the present invention include the following effects.
According to the first aspect, since the secondary curvature portion is formed on at least a portion of the contour of the projection viewed from the axial direction of the first flange portion of the yarn accumulating roller, a travelling position of the spun yarn on the yarn hooking member is constantly changed and the lifting up of the travelling spun yarn from the first flange portion of the yarn accumulating roller is reduced. Therefore, chances of the spun yarn entering between the yarn hooking member and the first flange portion of the yarn accumulating roller can be reduced, and a functional failure such as winding of the spun yarn around a roller shaft of the yarn accumulating roller can be prevented.
According to the second aspect, in addition to the effects of the first aspect, a change in a diameter of the yarn accumulating roller can be gradually maintained. Therefore, the travelling spun yarn unwound from the yarn accumulating roller can smoothly travel through the first flange portion of the yarn accumulating roller.
According to the third aspect, in addition to the effects of the second aspect, the change in the diameter of the yarn accumulating roller can be gradually maintained by reducing proportion of the secondary curvature portion. Therefore, the travelling spun yarn unwound from the yarn accumulating roller can smoothly travel through the first flange portion of the yarn accumulating roller.
According to the fourth aspect, in addition to the effects of the second aspect, the change in the diameter of the yarn accumulating roller can be gradually maintained by reducing proportion of the secondary curvature portion. Therefore, the travelling spun yarn unwound from the yarn accumulating roller can smoothly travel through the first flange portion of the yarn accumulating roller.
According to the fifth aspect, in addition to the effects of the first to fourth aspects, the yarn accumulating roller can be easily and accurately produced by cutting a circular shape and forming a straight line portion for the secondary curve portion.
According to the sixth aspect, in addition to the effects of the first to fifth aspects, the yarn accumulating device for constantly changing the travelling position of the spun yarn on the yarn hooking member and suppressing the travelling spun yarn from lifting up from the first flange portion of the yarn accumulating roller can be easily achieved.
According to the seventh aspect, in addition to the effects of the first to sixth aspects, the yarn accumulating device including the upstream guide and the downstream guide is achieved. Therefore, the spun yarn can be appropriately guided to the yarn accumulating device, and the spun yarn can be appropriately unwound from the yarn accumulating device.
According to the eighth aspect, in addition to the effects of the first to seventh aspects, the yarn accumulating device including the first flange portion, the second flange portion, and the winding portion is achieved. Therefore, the spun yarn can be guided to the winding portion by the second flange portion, and the spun yarn can be wound and accumulated by the winding portion.
According to the ninth aspect, in addition to the effects of the first to eighth aspects, the spinning machine including the yarn accumulating device having the above effects, the spinning device, and the winding device is achieved. Thus, the spun yarn fed from the spinning device can be accumulated by the yarn accumulating device, and the spun yarn unwound from the yarn accumulating device can be wound into a package by the winding device. Therefore, a winding tension of the spun yarn can be adjusted before the spun yarn spun by the spinning device is wound by the winding device.
According to the tenth aspect, since the straight line portion is formed on at least a portion of the contour of the projection viewed from the axial direction of the first flange portion of the yarn accumulating roller, the travelling position of the spun yarn on the yarn hooking member is constantly changed and the lifting up of the travelling spun yarn from the first flange portion of the yarn accumulating roller can be suppressed. Therefore, the chances of the spun yarn entering between the yarn hooking member and the first flange portion of the yarn accumulating roller can be reduced, and the functional failure such as winding of the spun yarn around the roller shaft of the yarn accumulating roller can be prevented.
According to the eleventh aspect, in addition to the effects of the tenth aspect, the change in the diameter of the yarn accumulating roller can be gradually maintained. Therefore, the travelling spun yarn unwound from the yarn accumulating roller can smoothly travel through the first flange portion of the yarn accumulating roller.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating an overall configuration of a spinning machine provided with a yarn accumulating device according to an embodiment of the present invention;
FIG. 2 is a schematic view illustrating an overall configuration of the yarn accumulating device;
FIG. 3 is a side cross-sectional view illustrating an internal structure of the yarn accumulating roller;
FIG. 4A is a side view illustrating a roller main body of the yarn accumulating roller, and FIG. 4B is a plan view illustrating the roller main body of the yarn accumulating roller;
FIG. 5 is a plan view illustrating a relative rotation of the yarn accumulating roller and a yarn hooking member;
FIG. 6 is a plan view illustrating a state in which a spun yarn is unwound from the yarn accumulating roller.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A spinning machine provided with a yarn accumulating device according to an embodiment will be described with reference to FIG. 1. A spinning machine 20 includes a draft device 21, a spinning device 22, a yarn clearer 38, a yarn accumulating device 24, and a winding device 25 which are arranged in this order from an upstream side along a yarn travelling direction in which spun yarn Y is produced from a sliver YS. The spinning machine 20 includes a yarn splicing device 26 installed in a yarn splicing cart 48 that moves among a plurality of spinning machines 20.
The draft device 21 uses rollers to sandwich and draft the sliver YS pulled out from cans (not illustrated). The draft device 21 includes four sets of rollers, a back roller pair 28, a third roller pair 29, a middle roller pair 31, and a front roller pair 32, which are arranged in this order from the upstream side in the yarn travelling direction. An apron belt 30 is wound around each roller of the middle roller pair 31.
The spinning device 22 applies whirling airflow on a fiber bundle YD fed from the front roller pair 32 of the draft device 21 to produce the spun yarn Y.
The yarn clearer 38 detects a yarn defect of the spun yarn Y that is being fed to the winding device 25. A defective portion of the spun yarn Y is removed based on yarn defect detection information by the yarn clearer 38, and winding of the defective spun yarn into a package YP is prevented. The yarn clearer 38 may be adapted to monitor not only the yarn defect but also a standard deviation of a yarn thickness of the spun yarn Y.
When the yarn defect detection information is transmitted from the yarn clearer 38 to a controller (not illustrated), the controller immediately cuts the spun yarn Y with a cutter 37, and stops the draft device 21, the spinning device 22, and the like. The yarn splicing cart 48, to be described later, is then travelled to the front of the spinning machine 20. The spinning device 22 and the like are driven again, the yarn splicing device 26 installed in the yarn splicing cart 48 carries out yarn splicing, and the spinning and the winding are resumed.
The yarn splicing cart 48 includes a suction pipe 49 and a suction mouth 50. The suction pipe 49 sucks and catches a yarn end fed from the spinning device 22 at a position indicated with a chain double dashed line in FIG. 1, and guides the caught yarn end to the yarn splicing device 26 while swinging. The suction mouth 50 sucks and catches the yarn end from the package YP at a position indicated with a chain double dashed line in FIG. 1, and guides the caught yarn end to the yarn splicing device 26 while swinging.
The yarn accumulating device 24 adjusts a winding tension of the spun yarn Y before the spun yarn Y spun by the spinning device 22 is wound by the winding device 25. The details of the yarn accumulating device 24 will be described later.
The winding device 25 winds the spun yarn Y produced by the spinning device 22 around a bobbin to produce the package YP. The winding device 25 includes a cradle arm 45, a winding drum 47, and a traverse device (not illustrated) . The cradle arm 45 is swingably supported with a supporting shaft 44 as a center, and rotatably supports the bobbin around which the spun yarn Y is wound. The winding drum 47 is rotatably driven while making contact with a peripheral surface of the bobbin or the package YP. A traverse device traverses the spun yarn Y at a predetermined width. When the winding drum 47 is rotatably driven by an electric motor (not illustrated), the package YP in contact with the winding drum 47 is passively driven and rotated, and the spun yarn Y is wound into the package YP.
With such a configuration, in the spinning machine 20, the sliver YS is stretched by the draft device 21 to form a fiber bundle YD, and the fiber bundle YD is spun by the spinning device 22 to form the spun yarn Y. The spun yarn Y is fed by the yarn accumulating device 24 and wound by the winding device 25 to form the package YP.
In the spinning machine 20 of the present embodiment, the spun yarn Y produced by the spinning device 22 is fed to the winding device 25 arranged downstream in the yarn travelling direction by the yarn accumulating device 24. However, a yarn feeding device may be separately arranged between the spinning device 22 and the yarn accumulating device 24, and the spun yarn Y may be pulled out from the spinning device 22 by the yarn feeding device. The yarn feeding device includes a delivery roller, and a nip roller arranged to freely contact and separate to and from the delivery roller. The yarn feeding device feeds the spun yarn sandwiched between the delivery roller and the nip roller to the winding device 25 by the rotational drive of the delivery roller.
The yarn accumulating device 24 according to the present embodiment will be described with reference to FIG. 2. The yarn accumulating device 24 includes a yarn accumulating roller 39, a yarn hooking member 52, an electric motor 42, an upstream guide 40, an air cylinder 43, and a downstream guide 41.
The spun yarn Y is wound around an outer peripheral surface of the yarn accumulating roller 39, and the yarn accumulating roller 39 is rotated by the rotational drive of the electric motor 42. The details of the yarn accumulating roller 39 will be described later.
The yarn hooking member 52 is attached in a relatively rotatable manner with respect to the yarn accumulating roller 39. The yarn hooking member 52 concentrically rotates integrally with or independently from the yarn accumulating roller 39 depending on conditions. The yarn hooking member 52 guides the spun yarn Y towards the downstream guide 41 while making contact with the travelling spun yarn Y unwound from the yarn accumulating roller 39. The detailed structure of the yarn hooking member 52 will be described later.
The yarn hooking member 52 integrally rotates with the yarn accumulating roller 39 until a predetermined load is applied by the travelling spun yarn Y which is making contact with the yarn hooking member 52. As hereinafter described, when the yarn accumulating roller 39 is rotated in one direction with the upstream guide 40 at a retreating position, the spun yarn Y is engaged to the yarn hooking member 52 and the spun yarn Y is wound around the yarn accumulating roller 39 until a predetermined load is applied on the yarn hooking member 52. When a load exceeding the predetermined load is applied on the yarn hooking member 52, the yarn hooking member 52 independently rotates with respect to the yarn accumulating roller 39, and the spun yarn Y wound and accumulated by the yarn accumulating roller 39 is gradually unwound. When unwinding the spun yarn Y accumulated on the yarn accumulating roller 39, the yarn hooking member 52 prevents sloughing of the spun yarn Y and guides the spun yarn Y such that the spun yarn Y is averagely unwound from the yarn accumulating roller 39. The yarn hooking member 52 makes contact with the spun yarn Y to exert a predetermined resistance thereby obtaining an appropriate winding tension of the spun yarn Y.
The upstream guide 40 is arranged upstream in the yarn travelling direction than the yarn accumulating roller 39, and guides the spun yarn Y to the yarn accumulating roller 39. The upstream guide 40 is supported by the air cylinder 43. The electric motor 42 and the air cylinder 43 are supported by the spinning machine 20 via a fixing member such as a bracket 51.
With such a configuration, when the upstream guide 40 is at an advancing position illustrated with a chain double dashed line in FIG. 2, a yarn path in which the spun yarn Y does not engage the yarn hooking member 52 is formed. On the other hand, when the upstream guide 40 is at the retreating position illustrated with a solid line in FIG. 2, the yarn path formed by the upstream guide 40 and the downstream guide 41 crosses a rotational trajectory surface of the yarn hooking member 52, and the spun yarn Y is engaged with the yarn hooking member 52 and is wound around the yarn accumulating roller 39.
By moving the upstream guide 40 to the advancing position, for example, immediately before the yarn splicing by the yarn splicing device 26, the upstream yarn end is prevented from being pulled towards the yarn accumulating roller 39 and not being guided to the yarn splicing device 26. By moving the upstream guide 40 to the retreating position, during yarn splicing, the spun yarn Y spun by the spinning device 22 is prevented from being retained at upstream of the yarn splicing device 26. If the upstream guide 40 is at the retreating position, during normal winding, the spun yarn Y is wound around the yarn accumulating roller 39 thus resolving a slackening of the spun yarn Y, and the winding tension is adjusted.
The downstream guide 41 is arranged downstream of the yarn accumulating roller 39 in the yarn travelling direction, and guides the spun yarn Y to the winding device 25. The downstream guide 41 is arranged such that an intersection of the upper end of the downstream guide 41 and the spun yarn Y is on an axial line of the yarn accumulating roller 39. The downstream guide 41 is supported by the spinning machine 20 via a fixing member such as the bracket 51.
The yarn accumulating roller 39 will be described with reference to FIG. 3. The yarn accumulating roller 39 includes a roller main body 60, a nut member 55, and an adjustment bolt 56. A recess 68 is formed on a downstream end face of the roller main body 60 in the yarn travelling direction. The nut member 55 is integrally fixed to the recess 68 of the roller main body 60. The adjustment bolt 56 is screw fitted to the nut member 55. Each axial center of the roller main body 60, the nut member 55, and the adjustment bolt 56 is arranged to coincide.
The roller main body 60 is fixed to a motor shaft 42A of the electric motor 42 with a fixing screw 69 screwed in from a radial direction of the roller main body 60. The details on the shape of the roller main body 60 will be described later.
The adjustment bolt 56 has a tube hole that penetrates in an axial direction. A threaded portion 75 is formed on the outer peripheral surface of the shaft part of the adjustment bolt 56 and the inner peripheral surface of the nut member 55. The adjustment bolt 56 is screw fitted to the nut member 55 by the threaded portion 75.
The yarn hooking member 52 includes a flyer shaft 71 and a flyer 72. The flyer shaft 71 is inserted to the tube hole of the adjustment bolt 56, and rotatably attached to both the inner peripheral surface of the nut member 55 and the inner peripheral surface of the adjustment bolt 56 via a bearing 74. The distal end of the flyer shaft 71 projects out from the end face of the adjustment bolt 56 and the roller main body 60. The flyer 72 is fixed to the distal end of the flyer shaft 71. The flyer shaft 71 includes a cylindrical portion 73 having a slightly larger diameter midway in the axial direction thereof. The outer peripheral surface of the cylindrical portion 73 is arranged to radially face the inner peripheral surface of the adjustment bolt 56 with a predetermined gap therebetween.
The flyer 72 made of ceramic or the like is attached to the distal end of the flyer shaft 71 in the radial direction of the roller main body 60. The flyer 72 is configured to integrally rotate with the flyer shaft 71, and is formed to curve towards the roller main body 60.
A permanent magnet 76 is arranged on an outer peripheral surface of the cylindrical portion 73 of the yarn hooking member 52. A hysteresis material 77 that is a semi-hard material is arranged on an inner peripheral surface of the adjustment bolt 56. The permanent magnet 76 is alternately polarized such as N pole, S pole, N pole, S pole, ... in the peripheral direction. When the permanent magnet 76 and the hysteresis material 77 face each other, a rotational resistance of the flyer shaft 71 with respect to the roller main body 60, that is, a rotational resistance of the yarn hooking member 52 with respect to the yarn accumulating roller 39 is generated by the magnetic coupling of the permanent magnet 76 and the hysteresis material 77. A predetermined load described above that is a boundary of whether the yarn hooking member 52 integrally rotates or independently rotates with respect to the yarn accumulating roller 39 is determined from the rotational resistance.
With such a configuration, when the adjustment bolt 56 is rotated and moved in the axial direction, an opposing area of the permanent magnet 76 and the hysteresis material 77 changes, magnetic coupling of the permanent magnet 76 and the hysteresis material 77 changes, and a magnitude of the rotational resistance can be adjusted. For example, if the opposing area is large, the magnetic coupling becomes stronger and the rotational resistance becomes greater. If the opposing area is small, the magnetic coupling becomes weaker and the rotational resistance becomes smaller. The yarn accumulating roller 39 may include an electromagnet instead of the permanent magnet 76.
The shape of the roller main body 60 will be described with reference to FIG. 4A and FIG. 4B. FIG. 4A illustrates a side view of the roller main body 60. FIG. 4B illustrates a plan view of the roller main body 60 seen from the downstream side in the yarn travelling direction. The roller main body 60 includes an upstream flange portion 62 as a second flange portion, a winding portion 63, and a downstream flange portion 64 as a first flange portion. The upstream flange portion 62 and the downstream flange portion 64 include a gradual inclined surface such that the diameter increases towards the respective end face side on the upstream or the downstream in the yarn travelling direction. The winding portion 63 is formed by concentric circles having substantially the same diameter, and is formed seamlessly in continuation to the upstream flange portion 62 and the downstream flange portion 64. The spun yarn Y unwound from the roller main body 60 is unwound while making contact with a largest diameter portion where the diameter of the downstream flange portion 64, and travels downstream towards the downstream guide 41.
The winding portion 63 may not be formed from concentric circles having substantially the same diameter. Specifically, the winding portion 63 may be formed in a tapered shape in which the diameter becomes smaller from the upstream side, where the winding of the spun yarn Y starts, towards the downstream side. The winding portion 63 formed in a tapered shape may be configured such that a taper angle becomes gradually smaller towards the downstream side. Specifically, a taper angle of an upstream taper region of the winding portion 63 may be formed to be smaller than a taper angle of a downstream taper region. Further, the number of taper regions of the winding portion 63 is not limited to two, i.e., the upstream taper region and the downstream taper region, and three taper regions may be formed.
A plurality of planar portions 65 (four in the present embodiment) and a plurality of curved surface portions 66 (four in the present embodiment) are formed in the downstream flange portion 64 (hereinafter, simply referred to as the flange portion 64) of the roller main body 60. In the flange portion 64, the planar portion 65 and the curved surface portion 66 are alternately formed, and are not respectively formed continuously. The number of planar portions 65 and curved surface portions 66 in the flange portion 64 is not limited to the present embodiment. Specifically, the number of planar portions 65 and curved surface portions 66 may be three or five or more, respectively. In other words, the spun yarn Y is prevented from being lifted up from the flange portion 64 and from being entangled to the rotation shaft of the yarn accumulating device 24 by providing at least three planar portions 65 and at least three curved surface portions 66.
The four planar portions 65 formed on the flange portion 64 are formed so that the planar portions 65 that face each other are parallel to each other, and the extended planes of the planar portions 65 adjacent to each other are orthogonal to each other. The four planar portions 65 formed on the flange portion 64 are formed by processing four areas of the flange portion 64 flat.
The respective parallel and orthogonal relationships of the planar portions 65 formed on the flange portion 64 are not limited to the present embodiment. However, distance from the rotation axis of each of the opposing planar portions 65 is equal. Further, distance from the rotation axis of the adjacent planar portions 65 is different.
The shape of the flange portion 64 will now be described with reference to a contour 64L of a projection viewed from the downstream side of the roller main body 60 in an axial direction. The contour 64L of the projection viewed from the downstream side of the roller main body 60 in the axial direction is formed by a plurality of (four in the present embodiment) straight line portions 65L formed in a substantially linear form serving as secondary curvature portions and a plurality of (four in the present embodiment) curved portions 66L. The projection viewed from the downstream side of the roller main body 60 in the axial direction does not include the upstream flange portion 64. The straight line portion 65L is obtained by projecting the planar portion 65 from the downstream side of the roller main body 60 in the axial direction. The curved portion 66L is obtained by projecting the curved surface portion 66 from the downstream side of the roller main body 60 in the axial direction. The straight line portion 65L is not limited to being formed in a substantially linear form and may have any shape as long as the straight line portion 65L is an arc having a curvature smaller than the curvature of the arc of the contour 64L.
A total length of the straight line portion 65L is formed to be at most half of the circumference of the contour 64L (entire circumference including the straight line portion 65L). A total of central angles of the straight line portion 65L (central angles when viewing the straight line portion 65L as a chord having the center axis 60A of the roller main body 60 as the center) is formed to be at most 180 degrees. The straight line portion 65L is formed by cutting a circular shape of the contour 64L of the flange portion 64.
As described above, since the planar portion 65 is formed on the flange portion 64, the spun yarn Y is unwound from the roller main body 60 while making contact with the flange portion 64. When the spun yarn Y makes contact with the planar portion 65, the spun yarn Y lifts up from the flange portion 64, and the tension of the spun yarn Y lowers and the spun yarn Y slackens. However, when the spun yarn Y makes contact with the curved surface portion 66, the unwound spun yarn Y makes contact with the flange portion 64 (curved surface portion 66) so that the tension is restored and the slackening of the spun yarn Y is suppressed. That is, while the yarn hooking member 52 rotates around the yarn accumulating roller 39 once, a phenomenon is repeated in which the tension of the spun yarn Y lowers by a number of times corresponding to the number of the planar portions 65 and the tension of the spun yarn Y is restored by a number of times corresponding to the number of curved surface portions 66. Since the tension is restored immediately afterwards even if the tension lowers, the lifting up of the spun yarn Y travelling through the flange portion 64 from the flange portion 64 of the roller main body 60 can be suppressed. Thus, the chances of the spun yarn Y entering between the yarn hooking member 52 and the flange portion 64 of the roller main body 60 can be reduced. In addition, the functional failure due to winding of the spun yarn Y around the roller shaft of the yarn accumulating roller 39, or the like can be prevented.
For example, in the yarn accumulating device in which the contour of the projection of the flange portion of the roller main body viewed from the downstream side of the roller main body in the axial direction is formed in an elliptical shape, the curvature changes over the entire circumference of the contour. Therefore, while the yarn hooking member rotates around the yarn accumulating roller once, the tension of the spun yarn may lower at a short axis portion and the spun yarn may lift up from the flange portion of the yarn accumulating roller. On the other hand, in the yarn accumulating device 24 of the present embodiment, the planar portion 65 is formed at the flange portion 64. Thus, while the yarn hooking member 72 rotates around the yarn accumulating roller 39 once, the lowering and restoration of the tension of the spun yarn Y are repeated and the spun yarn Y does not lift up from the flange portion 64 of the yarn accumulating roller 39.
In the yarn accumulating device in which the flange portion of the roller main body is elliptical, sloughing of the spun yarn from the roller main body may be caused at the short axis portion. On the other hand, in the yarn accumulating device 24 of the present embodiment, the planar portion 65 is arranged in a divided manner around the yarn accumulating roller 39. In other words, the time in which the spun yarn Y becomes unstable at one planar portion 65 is short compared to elliptical flange portion. Therefore, in the yarn accumulating device 24 of the present embodiment, the sloughing of the spun yarn Y from the yarn accumulating roller 39 can be avoided when the spun yarn Y is at the planar portion 65.
The relative rotation of the yarn hooking member 52 and the roller main body 60 will be described with reference to FIG. 5. In FIG. 5, when the yarn hooking member 52 relatively rotates with respect to the roller main body 60, a case in which the yarn hooking member 52 is located at the curved surface portion 66 is illustrated with a solid line and a case in which the yarn hooking member 52 is located at the planar portion 65 is illustrated with a chain double dashed line. The rotational trajectory of the yarn hooking member 52 is a circle, and the contour 64L of the flange portion 64 of the yarn accumulating roller 39 is a polygon including the curved portion 66L and the straight line portion 65L.
With such a configuration, when viewed from the axial direction of the yarn accumulating roller 39 (direction perpendicular to the plane of drawing in FIG. 5), the intersection of the contour 64L of the flange portion 64 of the yarn accumulating roller 39 and the flyer 72 of the yarn hooking member 52 differs for the case in which the yarn hooking member 52 is located at the straight line portion 65L and the case in which the yarn hooking member 52 is located at the curved portion 66L. In other words, the intersection differs depending on the rotation position of the yarn hooking member 52 with respect to the yarn accumulating roller 39. The spun yarn Y wound around the yarn accumulating roller 39 travels while making contact with the flange portion 64 of the roller main body 60, travels while making contact with the flyer 72 of the yarn hooking member 52, and is pulled out onto the axial line of the yarn accumulating roller 39 towards the downstream guide 41.
A state in which the spun yarn Y is unwound from the yarn accumulating roller 39 will be described with reference to FIG. 6. In FIG. 6, a case in which the yarn hooking member 52 is located at the curved portion 66L is indicated with a solid line, and a case in which the yarn hooking member 52 is located at the straight line portion 65L is illustrated with a chain double dashed line. When the yarn hooking member 52 relatively rotates with respect to the yarn accumulating roller 39, the position where the yarn hooking member 52 and the spun yarn Y to be unwound makes contact changes within a width D.
With such a configuration, the position where the yarn hooking member 52 and the spun yarn Y makes contact does not become constant, and changes within a predetermined width D. Therefore, the wear does not partially advance in the yarn hooking member 52 with respect to the wear caused by the travelling of the spun yarn Y, and a lifespan of the yarn hooking member 52 can be lengthened. Therefore, the spinning machine 20 is less likely to be stopped and the yarn hooking member 52 is less likely to be replaced due to problems such as breakage of the yarn hooking member 52 due to wear, and productivity of the package YP can be improved.
The travelling position of the spun yarn Y on the yarn hooking member 52 is thus constantly changed. Further, the lifting up of the travelling spun yarn Y from the flange portion 64 of the yarn accumulating roller 39 is suppressed, and the chances the spun yarn Y enters between the yarn hooking member 52 and the flange portion 64 of the yarn accumulating roller 39 are reduced. Therefore, the functional failure that occurs when the spun yarn Y is wound around the roller shaft of the yarn accumulating roller 39 can be prevented.

Claims

A yarn accumulating device comprising:
a roller main body (60) adapted to wind spun yarn around an outer peripheral surface thereof by being rotated; and

a yarn hooking member (52) attached to a downstream end of the roller main body (60) in a yarn travelling direction, and adapted to assist unwinding of the spun yarn from the roller main body (60) by relatively rotating with the roller main body (60) while making contact with the spun yarn,

wherein a first flange portion (64) is formed on the roller main body (60), and a diameter of the first flange portion (64) increases towards the downstream end in the yarn travelling direction, characterized in that

at least a portion of a contour (64L) of a projection viewed from an axial direction of the first flange portion (64) is formed as a secondary curvature portion (65L) having a smaller curvature than a curvature of a curved portion (66L) of the contour (64L), wherein the contour (64L) is formed by at least three secondary curvature portions (65L) and at least three curved portions (66L), which are alternately arranged.
A yarn accumulating device comprising:
a roller main body (60) adapted to wind spun yarn around an outer peripheral surface thereof by being rotated; and

a yarn hooking member (52) attached to a downstream end of the roller main body (60) in a yarn travelling direction, and adapted to assist unwinding of the spun yarn from the roller main body (60) by relatively rotating with the roller main body (60) while making contact with the spun yarn,

wherein a first flange portion (64) is formed on the roller main body (60), and a diameter of the first flange portion (64) increases towards the downstream end in the yarn travelling direction, characterized in that

a straight line portion (65L) is formed on at least a portion of a contour (64L) of a projection viewed from an axial direction of the first flange portion (64).
The yarn accumulating device according to claim 1, wherein the secondary curvature portions (65L) are formed at most half of a circumference of the contour (64L).
The yarn accumulating device according to claim 1, wherein a total of central angle of the secondary curvature portions (65L) is at most 180 degrees.
The yarn accumulating device according to claim 2, wherein the straight line portion (65L) is formed at most half of a circumference of the contour (64L).
The yarn accumulating device according to claim 2, wherein a total of central angle of the straight line portion (65L) is at most 180 degrees.
The yarn accumulating device according to any one of claim 2, 5 or 6, wherein the contour (64L) of the projection viewed from an axial direction of the first flange portion (64) is formed in substantially circular shape, and the straight line portion (65L) is formed by cutting the substantially circular shape.
The yarn accumulating device according to any one of claim 2, 5 or 6, wherein at least three straight line portions (65L) are formed on the contour (64L) of the projection viewed from the axial direction of the first flange portion (64).
The yarn accumulating device according to any one of claim 1 through claim 8, further comprising:
an upstream guide (40) arranged upstream in the yarn travelling direction than an opposite side of the side where the first flange portion (64) of the roller main body (60) is formed, and adapted to guide the spun yarn to the roller main body (60); and

a downstream guide (41) arranged downstream in the yarn travelling direction than the first flange portion (64) of the roller main body (60), and adapted to guide the yarn unwound from the roller main body (60).
The yarn accumulating device according to any one of claim 1 through claim 9, wherein the roller main body (60) includes:
the first flange portion (64),

a second flange portion (62) formed on a side opposite from the side where the first flange portion (64) is formed, and

a winding portion (63) formed between the first flange portion (64) and the second flange portion (62) and formed smaller than an outer shape of the first flange portion (64) and an outer shape of the second flange portion (62), and adapted to wind the spun yarn.
A spinning machine comprising:
the yarn accumulating device (24) according to any one of claim 1 through claim 10;

a spinning device (22) arranged upstream of the yarn accumulating device (24) in a yarn travelling direction and adapted to produce the spun yarn; and

a winding device (25) arranged downstream of the yarn accumulating device (24) in the yarn travelling direction and adapted to wind the spun yarn produced by the spinning device (22) into a package.