EP2045377A1

EP2045377A1 - Fiber bundle concentrating apparatus in spinning machine

Info

Publication number: EP2045377A1
Application number: EP08165458A
Authority: EP
Inventors: Koji Maeda; Kazuo Seiki; Naoki Maruyama
Original assignee: Toyota Industries Corp
Current assignee: Toyota Industries Corp
Priority date: 2007-10-05
Filing date: 2008-09-30
Publication date: 2009-04-08
Anticipated expiration: 2028-09-30
Also published as: CN101451283A; JP2009091679A; CN101451283B; EP2045377B1

Abstract

A fiber bundle concentrating apparatus 30 includes a guide member 31, which guides a fiber bundle such that the width of the fiber bundle is reduced toward an advancing direction of the fiber bundle, and an excitation device 32, which vibrates the guide member 31 so as to generate sound pressure that acts on the fiber bundle in a direction to reduce the width of the fiber bundle. The guide member 31 includes two vibration plates 41 arranged to face each other. Each vibration plate 41 includes a guide portion 41c, which forms a guide passage 44 the cross-sectional area of which is smaller at the outlet than at the inlet, and a support plate portion 41a, 41b, which has a proximal end coupled to a transducer 37 of the excitation device 32 and a distal end at which the guide portion 41c is integrally formed. Each guide portion 41c is formed into a shape that permits the sound pressure to act on the fiber bundle that pass at least the inlet guide passage 44b of the guide passage 44 from a side corresponding to an opposing surface 45a that faces the other guide portion and from a side corresponding to a surface 45b that intersects the opposing surface.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a fiber bundle concentrating apparatus in a spinning machine, and more specifically, the present invention pertains to a fiber bundle concentrating apparatus that is located downstream of a draft machine (draft part) of a ring spinning frame and concentrates a fiber bundle drafted by the draft machine in a suitable manner.
Several types of fiber bundle concentrating apparatuses in ring spinning frame have been proposed that concentrate a drafted fiber bundle before a twisting process to gain high quality yarn with reduced unevenness and fuzzing. As methods for concentrating a fiber bundle, a method that uses a mechanical guide (collector) and a method that applies suction air flow to a fiber bundle moving along a perforated belt (ventilation apron) are general.
Guide members such as the mechanical guide and the perforated belt used in these methods guide the fiber bundle in a state where the guide members contact the fiber bundle. To guide a fiber bundle without disturbing the arrangement of fibers in the fiber bundle, it is necessary to take measures to reduce friction between the surface of the guide members and the fiber bundle. Japanese Laid-Open Patent Publication No. 2007-9391 proposes a fiber bundle guiding apparatus that reduces friction between a fiber bundle and guide members. The fiber bundle guiding apparatus of the above publication is provided with guide members, which include a pair of guide surfaces that guide a fiber bundle moving along an advancing direction such that the width of the fiber bundle is reduced, and an excitation device, which vibrates the guide members so as to generate sound pressure that acts on the fiber bundle in a direction to reduce the width of the fiber bundle. The above publication discloses guide members, which include a pair of flat plates arranged parallel to each other and guide surfaces configured by opposing surfaces of the flat plates, and a guide member 61 as shown in Fig. 6. The guide member 61 is formed by a cylindrical body, the cross-sectional shape of which is reduced toward the advancing direction of the fiber bundle, and includes a groove 62 that is continuous from one end to the other end. A guide surface 62a is configured by inner surfaces of the groove 62 facing each other. A transducer 63 oscillates the guide member 61 at a predetermined resonance frequency (for example, around 34 kHz) so that sound pressure is generated from the guide surface 62a. This reduces friction between the guide surface 62a and the fiber bundle.
However, when the guide member is formed by two flat plates, the fiber bundle spreads in a direction perpendicular to the advancing direction of the fiber bundle along the guide surfaces of the flat plates. Thus, the fiber bundle is not sufficiently concentrated. Also, when the guide member 61 is formed by a cylindrical body as shown in Fig. 6, resonance is not easily produced because of high rigidity of the guide member 61. Thus, the amplitude required as the guide for fiber bundle is not easily obtained.

SUMMARY OF THE INVENTION

Accordingly, it is an objective of the present invention to provide a fiber bundle concentrating apparatus in a spinning machine that suppresses a fiber bundle from spreading in a direction perpendicular to the advancing direction of the fiber bundle and improves the quality of spun yarn.
To achieve the foregoing objective and in accordance with one aspect of the present invention, a fiber bundle concentrating apparatus in a spinning machine is provided. The fiber bundle concentrating apparatus includes a guide member, which guides a fiber bundle such that the width of the fiber bundle is reduced toward an advancing direction of the fiber bundle, and an excitation device, which vibrates the guide member so as to generate sound pressure that acts on the fiber bundle in a direction to reduce the width of the fiber bundle. The guide member includes two vibration plates arranged to face each other. Each vibration plate includes a guide portion, which forms a guide passage the cross-sectional area of which is smaller at the outlet than at the inlet, and a support plate portion, which includes a proximal end coupled to a transducer of the excitation device and a distal end at which the guide portion is integrally formed. The guide passage includes an inlet guide passage. Each guide portion is formed into a shape that permits the sound pressure to act on the fiber bundle that passes at least the inlet guide passage of the guide passage from a side corresponding to an opposing surface that faces the other guide portion and from a side corresponding to a surface that intersects the opposing surface.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:

Fig. 1A is a side view illustrating a draft machine according to one embodiment of the present invention;
Fig. 1B is a schematic view showing the positional relationship between the guide member and the bottom rollers in the draft machine of Fig. 1A;
Fig. 2A is a diagram illustrating the fiber bundle guiding apparatus in the draft machine of Fig. 1A as viewed from the inlets of the guide members;
Fig. 2B is a partial side view illustrating the vibration plate of one of the guide members;
Fig. 3A is a schematic perspective view illustrating the guide member of Fig. 2B;
Fig. 3B is a view illustrating the guide member of Fig. 3A as viewed from the inlet;
Fig. 4A is a graph showing comparison of the number of fuzzing fibers of spun yarn;
Fig. 4B is a graph showing comparison of the single yarn strength of spun yarn;
Fig. 5A, 5B, 5C, and 5D are diagrams illustrating guide members of modified embodiments as viewed from the inlets; and
Fig. 6 is a schematic perspective view illustrating a conventional guide member.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A ring spinning frame according to one embodiment of the present invention will now be described with reference to Figs. 1A to 4B.
As shown in Fig. 1A, a draft machine 11 is a four-line type and includes a three-line type draft part and a pair of final delivery rollers 24 located downstream of the draft part in the advancing direction of a fiber bundle F. The three-line type draft part includes a front bottom roller 12, a middle bottom roller 13, and a back bottom roller 14. Support brackets 16, 17 are secured to a roller stand 15, which configures a base, to be adjustable in the front and rear direction. The middle bottom roller 13 and the back bottom roller 14 are supported by the support brackets 16, 17, respectively.
A front top roller 21, a middle top roller 22, and a back top roller 23 are supported by a frame 20b of a weighting arm 20 by means of top roller support members so as to correspond to the front bottom roller 12, the middle bottom roller 13, and the back bottom roller 14, respectively. The weighting arm 20 includes a lever 20a, which is rotatable to a pressurizing position and a releasing position. As shown in Fig. 1A, when the lever 20a is located at the pressurizing position at which the lever 20a contacts the frame 20b, the top rollers 21, 22, 23 supported by the weighting arm 20 are retained at a pressurizing position (spinning position) at which the top rollers 21, 22, 23 are pressed against the bottom rollers 12, 13, 14 in a locked state. When the lever 20a is rotated to the releasing position upward from the state shown in Fig. 1A, the top rollers 21, 22, 23 are unlocked.
The pair of final delivery rollers 24 includes a bottom nip roller 24a supported by the roller stand 15 and a top nip roller 24b supported by the weighting arm 20 by means of a support member. Like the front top roller 21 of the draft machine 11, the top nip roller 24b is supported by the weighting arm 20 with the support member at every other spindle.
A fiber bundle concentrating apparatus 30, which configures the fiber bundle guiding apparatus, is located between the pair of final delivery rollers 24 and the pair of front rollers 12, 21 located upstream of the final delivery rollers 24. As shown in Fig. 2A, the fiber bundle concentrating apparatus 30 includes a pair of guide members 31 and an excitation device 32, which vibrates the guide members 31.
The excitation device 32 is mounted on the base by means of a mounting bracket 33. The excitation device 32 includes a transducer 37. The transducer 37 includes a pair of piezoelectric devices 34 located on both sides of the bracket 33. The piezoelectric devices 34 are sandwiched between coupling members 35, 36. That is, the transducer 37 is configured by sandwiching two piezoelectric devices 34 and the mounting bracket 33 between the pair of coupling members 35, 36. The coupling members 35, 36 are configured by metal rods. The transducer 37 is preferably a Langevin transducer. Each of the piezoelectric devices 34 includes a pair of ring-shaped piezoelectric elements 34a, 34b and a ring-shaped electrode plate 38 located between the piezoelectric elements 34a, 34b.
An internal thread portion (not shown) is formed in the surface of the coupling member 35 that faces the piezoelectric device 34. A rod portion (not shown) including an external thread portion at its distal end projects from the surface of the other coupling member 36 that faces the piezoelectric device 34. The rod portion extends through the pair of piezoelectric devices 34 and the mounting bracket 33 located between the piezoelectric devices 34, and the external thread portion is screwed to the internal thread portion. Thus, the coupling members 35, 36 are supported by the mounting bracket 33 in a state where the piezoelectric devices 34 are tightened to the mounting bracket 33. Furthermore, the coupling members 35, 36 are electrically connected to the mounting bracket 33 by means of the rod portion. The guide members 31 are each mounted on the distal end of one of the coupling members 35, 36.
The transducer 37 is connected to an oscillator 39. The electrode plates 38 are connected to the oscillator 39 by wiring 40a, and a ground terminal of the oscillator 39 is connected to the mounting bracket 33 by wiring 40b. Thus, in each of the piezoelectric devices 34, the electric potential of the surface that contacts the mounting bracket 33 and the electric potential of the surface that contacts the corresponding coupling member 35 or 36 are at ground potential (zero). The oscillator 39 excites the transducer 37 such that the mounting bracket 33 is located at the nodes of the vibration and the distal ends of the coupling members 35, 36 are located at the antinodes of the vibration. The oscillator 39 excites the transducer 37 such that the guide members 31 vibrate at a frequency higher than the audible frequency.
As shown in Figs. 2A and 3A, each guide member 31 includes two vibration plates 41 arranged to face each other. In the preferred embodiment, the guide members 31 are formed to be symmetrical as viewed from the advancing direction of a fiber bundle. The vibration plates 41 are also formed to be symmetrical. Each vibration plate 41 includes a base portion 41a, a middle portion 41b, and a guide portion 41c. The width of the middle portion 41b is narrower than that of the base portion 41a in the advancing direction of the fiber bundle. The guide portion 41c is substantially perpendicular to the middle portion 41b and extends along the advancing direction of the fiber bundle. The base portion 41a and the middle portion 41b configure a support plate portion. A spacer 42 is integrally formed with the base portion 41a. Two vibration plates 41 are coupled to each other with the spacer 42 in between. In a state where the vibration plates 41, which are joined by the spacer 42, are abut against the distal end of the corresponding one of the coupling members 35, 36, a bolt 43 is inserted through the base portions 41a and the spacer 42, and screwed to a threaded bore, which is not shown, at the distal end of the associated coupling member 35 or 36. In this manner, the vibration plates 41 are tightened to the corresponding one of the coupling members 35, 36.
Fig. 2B is a partial side view of one of the pair of vibration plates 41 of each guide member 31 located on the right side facing the advancing direction of the fiber bundle. The vibration plate is viewed from the left side. As shown in Fig. 2B, the guide portion 41c includes a groove 44, which forms a downstream guide passage (outlet guide passage) 44a and an inlet guide passage (upstream guide passage) 44b, which is connected to the downstream guide passage 44a. Part of the groove 44 forming the downstream guide passage 44a includes a constant depth (dimension in the direction perpendicular to the sheet of Fig. 2B) and a constant width (dimension in the vertical direction in Fig. 2B). The guide portion 41c includes, as guide surfaces that form the downstream guide passage 44a, a flat surface 44a1 extending parallel to the advancing direction of the fiber bundle and a pair of auxiliary guide surfaces 44a2, which face each other. The auxiliary guide surfaces 44a2 restrict the fiber bundle that passes through the downstream guide passage 44a from moving along the flat surface 44a1 in a direction perpendicular to the advancing direction of the fiber bundle. Also, part of the groove 44 that forms the inlet guide passage 44b has a depth and a width that gradually increase toward the upstream section. That is, the cross-sectional area of the inlet guide passage 44b increases toward the upstream section. In the preferred embodiment, the vibration plates 41 are formed by, for example, pressing aluminum-based metal plates. The aluminum-based metal refers to aluminum or an aluminum alloy.
The guide portion 41c includes, as the guide surfaces that form the inlet guide passage 44b, a side inclination surface 45a and upper and lower inclination surfaces 45b, which intersect the side inclination surface 45a. An inlet guide passage forming section 45 of the guide portion 41c is formed into a shape that permits sound pressure to be applied to a fiber bundle from a side corresponding to the side inclination surface 45a and sides corresponding to the upper and lower inclination surfaces 45b. The side inclination surface 45a corresponds to one of opposing surfaces of the pair of vibration plates 41 of each guide member 31. The upper and lower inclination surfaces 45b are surfaces that intersect the side inclination surface 45a. That is, the inlet guide passage forming section 45 of the guide portion 41c is formed into a shape that permits sound pressure to be applied to a fiber bundle from a side corresponding to the opposing surface (side inclination surface 45a) of the vibration plate 41 and from sides corresponding to the surfaces intersecting the opposing surface (upper and lower inclination surfaces 45b). In this specification, "sides corresponding to the surfaces intersecting the opposing surface of the vibration plate" refers to the vertical direction and the diagonal direction when the fiber bundle advances in the horizontal direction, and refers to the horizontal direction and the diagonal direction when the fiber bundle advances in the vertical direction. In the preferred embodiment, as shown in Figs. 2A and 3B, the inlet guide passage forming section 45 is formed to have a channel-like cross-section. The inlet of part of the groove 44 forming the inlet guide passage 44b has a depth greater than the thickness D of the support plate portion configuring the base portion 41a and the middle portion 41b, and the width W of the inlet guide passage forming section 45 is greater than the thickness D of the support plate portion.
Each vibration plate 41 includes restricting portions 46a, 46b located downstream of the downstream guide passage 44a and upstream of the inlet guide passage 44b, respectively. The restricting portions 46a, 46b are triangular as viewed from the side and restrict movement of the fiber bundle in the left and right direction. The pair of vibration plates 41 are joined with the spacers 42 in between such that the guide portions 41c face each other with a gap in between that prevents the guide portions 41c from interfering with each other when vibrated by the excitation device 32.
The two vibration plates 41 configuring the guide member 31 each include a guide passage for guiding a fiber bundle. The guide passage includes the square frustum-like inlet guide passage 44b, and the downstream guide passage 44a which extends straight from the inlet guide passage 44b with a constant cross section. Each vibration plate 41 includes a guide surface that guides the fiber bundle F such that the width of the fiber bundle F is reduced toward the advancing direction of the fiber bundle F. The guide surface includes the flat surface 44a1, the auxiliary guide surfaces 44a2, the side inclination surface 45a, and the upper and lower inclination surfaces 45b. Depending on the spinning conditions, each guide member 31 is formed such that the gap between the opposing guide surfaces (flat surfaces 44a1) of the pair of downstream guide passages 44a is less than or equal to 1 mm.
Prior to operating the spinning frame, the position of the middle bottom roller 13 and the back bottom roller 14 is adjusted properly by adjusting the position of the support brackets 16, 17 in accordance with the spinning material. The position of the middle top roller 22 and the back top roller 23 is adjusted in accordance with the position of the middle bottom roller 13 and the back bottom roller 14.
When the spinning frame is operated, the fiber bundle F is drafted at the three-line type draft part of the draft machine 11, and then guided to the nip section of the pair of final delivery rollers 24 by means of the guide members 31, and fed out from the final delivery rollers 24. During operation of the spinning frame, as the oscillator 39 is driven, the transducer 37 is excited at the resonance frequency (for example, around 30 kHz) of the guide members 31. This causes the coupling members 35, 36 to vibrate longitudinally, thereby vibrating the guide members 31. Thus, sound pressure is generated from the wall surfaces of the inlet guide passages 44b and the downstream guide passages 44a. The sound pressure acts on the fiber bundle F in a direction to reduce its width.
The fiber bundle F is concentrated as it passes through the position corresponding to the inlet guide passages 44b and the downstream guide passages 44a. After passing through the nip point between the bottom nip roller 24a and the top nip roller 24b, the fiber bundle F moves downstream while being twisted. Then, the fiber bundle F is wound around a bobbin, which is not shown. The final delivery rollers 24 are rotated slightly faster than the surface velocity of the front bottom roller 12 and the front top roller 21. After passing through the nip point of the pair of final delivery rollers 24 with an appropriate tension, the fiber bundle F moves downstream while being twisted.
In the conventional art in which the guide member is configured by two flat vibration plates, sound pressure acts on the fiber bundle F only from the pair of opposing surfaces. Thus, the fiber bundle F spreads in a direction perpendicular to the advancing direction of the fiber bundle F along the opposing surfaces. In this case, the fiber bundle F is not sufficiently concentrated. However, in the preferred embodiment, at the inlet guide passage 44b located upstream of the advancing direction of the fiber bundle F, sound wave is generated so that sound pressure acts on the fiber bundle F from the sides corresponding to the opposing surfaces of the vibration plates 41, that is, the side inclination surfaces 45a and from the sides corresponding to the upper and lower inclination surfaces 45b that intersect the side inclination surfaces 45a (at right angles in this embodiment) to reduce the width of the fiber bundle F. As a result, unlike the conventional art, the fiber bundle F is guided while being suppressed from spreading in a direction perpendicular to the advancing direction of the fiber bundle F along the side inclination surfaces 45a. Therefore, the fiber bundle is sufficiently concentrated and the quality of the spun yarn is improved.
The quality of spun yarn that was spun using the ring spinning frame provided with the fiber bundle concentrating apparatus 30 of the preferred embodiment was compared with the quality of spun yarn that was spun using the ring spinning frame provided with the conventional fiber bundle concentrating apparatus, which included the guide member configured by two flat vibration plates.
A medium cotton yarn (combed yarn: 40 count) was spun at a spindle speed of 20000 rpm, and a thick cotton yarn (carded yarn: 10 count) was spun at a spindle speed of 10000 rpm. Obtained spun yarn was inspected for total number of fuzzing fibers (S3) longer than or equal to 3 mm that existed per 100 m, and the single yarn strength was checked. The results are shown in Figs. 4A and 4B. The quality of spun yarn is increased as the number of fuzzing fibers is reduced, and as the single yarn strength is increased.
As shown in Fig. 4A, the number of fuzzing fibers (S3) was significantly reduced by half or less in both the medium cotton yarn and the thick cotton yarn with the spinning frame (embodiment example) provided with the guide members 31 of the preferred embodiment as compared to the spinning frame (comparison example) provided with the conventional flat vibration plates. Furthermore, in the case with the medium cotton yarn, the single yarn strength was increased by approximately 30% with the spinning frame of the preferred embodiment compared to the single yarn strength obtained with the spinning frame of the comparison example. In the case with the thick cotton yarn, the single yarn strength was increased by 10% or more compared to the single yarn strength obtained with the spinning frame of the comparison example.
The preferred embodiment has the following advantages.

(1) The fiber bundle concentrating apparatus 30 is provided with the pair of guide members 31, which include guide surfaces that guide the fiber bundle F such that the width of the fiber bundle F is reduced toward the advancing direction of the fiber bundle F, and the excitation device 32, which vibrates the guide members 31 such that sound pressure acts on the fiber bundle F in a direction to reduce the width of the fiber bundle F. Each guide member 31 includes two vibration plates 41 arranged to face each other. Each vibration plate 41 includes the guide portion 41c, which configures the guide passage, the cross-sectional area of which at the downstream section is smaller than that of the upstream section, and the base portion 41a and the middle portion 41b, which configure the support plate portion. The transducer 37 is coupled to the proximal end of the support plate portion, and the guide portion 41c is formed integrally with the distal end of the support plate portion. The guide portion 41c is formed into a shape that permits sound pressure to be applied to the fiber bundle F passing through the guide passage in a direction to reduce the width of the fiber bundle F from the sides corresponding to the opposing surfaces of the vibration plates 41, that is, the flat surfaces 44a1 and the side inclination surfaces 45a, and from the sides corresponding to the surfaces intersecting the opposing surfaces, that is, the auxiliary guide surfaces 44a2 and the upper and lower inclination surfaces 45b. Therefore, unlike the conventional art, the fiber bundle F is guided while being suppressed from spreading in a direction perpendicular to the advancing direction of the fiber bundle F along the opposing surfaces of the vibration plates 41. Thus, the fiber bundle is sufficiently concentrated and the quality of the spun yarn is increased.
(2) The guide portion 41c includes, as the guide surfaces that form the downstream guide passage 44a, the flat surface 44a1, which extends parallel to the advancing direction of the fiber bundle F. The cross-section of the inlet guide passage 44b connected to the downstream guide passage 44a is increased toward the upstream section. Thus, the fiber bundle F is concentrated as it passes through the inlet guide passages 44b and the downstream guide passages 44a. Since the fiber bundle F receives sound pressure while passing through the downstream guide passages 44a, the fiber bundle F is kept in a concentrated state. Since the downstream guide passage 44a has the flat surface 44a1, which extends parallel to the advancing direction of the fiber bundle F, the thickness of the fiber bundle F fed from the guide portions 41c is stabilized.
(3) The guide members 31 are formed to be symmetrical as viewed from the advancing direction of the fiber bundle. Thus, using a single transducer 37, two vibration plates 41 configuring each guide member 31 are vibrated efficiently with necessary amplitude.
(4) The width W of the inlet guide passage forming section 45 having a channel-like cross-section is greater than the thickness D of the support plate portion. Therefore, the cross-sectional area of the inlet of the inlet guide passage can be increased without being restricted by the thickness D appropriate for vibration of the support plate portion, that is, the base portion 41a and the middle portion 41b. This suppresses clogging of fiber at the inlet.
(5) Each guide portion 41c includes the auxiliary guide surfaces 44a2, which restrict the fiber bundle F that passes through the downstream guide passage 44a from moving along the flat surface 44a1 in a direction perpendicular to the advancing direction of the fiber bundle F. Therefore, when the fiber bundle F passes through the downstream guide passages 44a, sound pressure acts on the fiber bundle F not only from the opposing surfaces of the vibration plates 41, that is, the flat surfaces 44a1, but also from the auxiliary guide surfaces 44a2. Thus, the fiber bundle F advances while maintaining the concentrated state.
(6) Each guide member 31 includes, in addition to the downstream guide passages 44a and the inlet guide passages 44b, which cover almost the entire fiber bundle F, the restricting portions 46a, 46b provided on both sides of the fiber bundle F in the advancing direction at sections downstream of the downstream guide passages 44a and upstream of the inlet guide passages 44b. Therefore, as compared to the configuration in which each guide member 31 is not provided with the restricting portions 46a, 46b, the fiber bundle F fed out from the front bottom roller 12 and the front top roller 21 is smoothly fed to the inlet guide passages 44b, and the fiber bundle F fed out from the downstream guide passages 44a is fed to the final delivery rollers 24 while remaining concentrated.
(7) Since the vibration plates 41 are formed by pressing, manufacturing costs are reduced as compared to a case where the vibration plates 41 are manufactured by cutting.

The embodiment is not limited to the above, but may be modified as follows, for example.
The cross-sectional shape of the inlet guide passages 44b of each guide member 31 is not limited to a rectangular shape as long as the cross-sectional area is increased toward the upstream section. For example, the inlet guide passages 44b may be formed to have a hexagonal cross-section as shown in Fig. 5A, or may be formed to have a circular cross-section as shown in Fig. 5B. In either case, when the guide members 31 are vibrated by the excitation device 32, sound wave is generated so that sound pressure acts on the fiber bundle F that passes through the inlet guide passages 44b from the sides corresponding to the opposing surfaces of the pair of vibration plates 41 and from the sides corresponding to the surfaces intersecting the opposing surfaces so as to concentrate the fiber bundle. As a result, the fiber bundle is sufficiently concentrated and the quality of the spun yarn is improved. Also, the cross-sectional shape of the inlet guide passages 44b may be any polygonal shape other than a rectangular shape and a hexagonal shape, and may be, for example, a triangular shape or an octagonal shape. Furthermore, the cross-sectional shape of the inlet guide passages 44b may be an elliptical shape instead of a circular shape.
When forming the guide members 31 to be symmetrical, the inlet guide passages 44b formed by the pair of guide portions 41c do not need to be formed into a shape that surrounds the entire circumference of the fiber bundle F. For example, as shown in Fig. 5C, the pair of guide portions 41c the cross-section of which is L-shaped may form a passage the top of which is open. A cover plate 47 may cover the open section to form the inlet guide passages 44b having a rectangular cross section. The cover plate 47 is secured to, for example, the weighting arm 20 (refer to Fig. 1A), and when the weighting arm 20 is at the pressurizing position, the cover plate 47 is arranged to cover the upper open section of the inlet guide passages 44b. With this configuration, the cover plate 47 is not vibrated. When the pair of vibration plates 41 are vibrated by the excitation device 32, sound pressure acts on the fiber bundle F that passes through the inlet guide passages 44b from left and right sides and below. Sound pressure is not applied to the fiber bundle F from the upper side of the inlet guide passages 44b, but the cover plate 47 suppresses the fiber bundle F from spreading in a direction perpendicular to the advancing direction of the fiber bundle F along the opposing surfaces of the pair of vibration plates 41. Therefore, the fiber bundle F that passes through the inlet guide passages 44b moves to the downstream guide passages 44a in a concentrated state, and passes through the downstream guide passages 44a while maintaining the concentrated state. As a result, the quality of spun yarn is improved as compared to the conventional art.
Each guide member 31 does not need to be formed by two symmetrical vibration plates 41, but may be configured by two vibration plates that are asymmetrical. For example, as shown in Fig. 5D, the guide member 31 may be configured by two asymmetrical vibration plates 48a, 48b. In this case, by vibrating the two vibration plates 48a, 48b using different excitation devices, the pair of guide portions 41c are vibrated with appropriate amplitude.
Each guide member 31 includes two vibration plates that are arranged to face each other. The vibration plates may be formed into any shape as long as the vibration plates configure the guide passage the cross-sectional area of which is reduced toward the downstream section compared to the upstream section, and sound pressure is applied to the fiber bundle F that passes through at least the inlet guide passages 44b of the guide passage from the sides corresponding to the opposing surfaces of the vibration plates and from the sides that intersect the opposing surfaces. For example, the downstream guide passage 44a formed in each guide portion 41c does not need to have two opposing auxiliary guide surfaces 44a2 but may include only the flat surface 44a1. Alternatively, the downstream guide passage 44a may include the flat surface 44a1 and only one of the two auxiliary guide surfaces 44a2. In these cases also, the fiber bundle F is concentrated in an appropriate manner at least when passing through the inlet guide passages 44b. As a result, the quality of spun yarn is improved as compared to the conventional art.
The restricting portions 46a, 46b may be omitted.
The distal ends of the coupling members 35, 36 may be displaced from the antinodes of the longitudinal vibration. However, the drive energy required for vibrating the guide members 31 in a desired vibration state is smaller when the distal ends of the coupling members 35, 36 are located at positions corresponding to the antinodes of the longitudinal vibration. When displacing the distal ends of the coupling members 35, 36 from the antinodes of the longitudinal vibration, the displacement is preferably within 20% of the distance between an adjacent antinode and node of the vibration.
Instead of manufacturing the vibration plates 41, 48a, 48b by pressing, the vibration plates 41, 48a, 48b may be manufactured by, for example, cutting or combination of pressing and cutting.
The vibration plates 41, 48a, 48b do not need to be formed of aluminum-based metal, but may be formed of other metals.
The middle portions 41b may be bent or curved in the middle.
Instead of tightening the guide members 31 to the coupling members 35, 36 with bolts, the guide members 31 may be secured to the coupling members 35, 36 by brazing, soldering, or using an adhesive.
Instead of the transducer 37, which is configured using a piezoelectric element, the excitation device 32 may be provided with the transducer 37, which is configured by a magnetostrictive element or a super-magnetostrictive element.
The fiber bundle concentrating apparatus 30 does not need to be the one used at a position between the final delivery rollers 24 and the front rollers 12, 21, which are located upstream of the final delivery rollers 24, in order to spin high-quality yarn called compact yarn. For example, in the draft machine of the spinning frame, the fiber bundle concentrating apparatus 30 may be used at a position between the back rollers and the middle rollers around which the apron is wound. In the spinning frame, there is a demand for spinning at a draft ratio higher than the current draft ratio. However, in the current draft machine, when the draft ratio between the back rollers and the middle rollers is increased, the width of the fiber bundle is spread between the back rollers and the middle rollers, and the fiber bundle enters the middle rollers in the spread state. Thus, the fiber bundle is not drafted in a suitable manner. However, by arranging the fiber bundle concentrating apparatus 30 configured as described above between the back rollers and the middle rollers, the width of the fiber bundle is reduced to a desired width before the fiber bundle enters the middle rollers around which the apron is wound. Therefore, as compared to the conventional art, although the draft machine is driven to increase the draft ratio at the back zone to increase the entire draft ratio, drafting is performed in a suitable manner at the apron zone.
A fiber bundle concentrating apparatus 30 includes a guide member 31, which guides a fiber bundle such that the width of the fiber bundle is reduced toward an advancing direction of the fiber bundle, and an excitation device 32, which vibrates the guide member 31 so as to generate sound pressure that acts on the fiber bundle in a direction to reduce the width of the fiber bundle. The guide member 31 includes two vibration plates 41 arranged to face each other. Each vibration plate 41 includes a guide portion 41c, which forms a guide passage 44 the cross-sectional area of which is smaller at the outlet than at the inlet, and a support plate portion 41a, 41b, which has a proximal end coupled to a transducer 37 of the excitation device 32 and a distal end at which the guide portion 41c is integrally formed. Each guide portion 41c is formed into a shape that permits the sound pressure to act on the fiber bundle that pass at least the inlet guide passage 44b of the guide passage 44 from a side corresponding to an opposing surface 45a that faces the other guide portion and from a side corresponding to a surface 45b that intersects the opposing surface.

Claims

A fiber bundle concentrating apparatus (30) in a spinning machine, the fiber bundle concentrating apparatus comprising a guide member (31), which guides a fiber bundle (F) such that the width of the fiber bundle is reduced toward an advancing direction of the fiber bundle, and an excitation device (32), which vibrates the guide member so as to generate sound pressure that acts on the fiber bundle in a direction to reduce the width of the fiber bundle,
wherein the guide member includes two vibration plates (41) arranged to face each other, each vibration plate including a guide portion (41c), which forms a guide passage (44) the cross-sectional area of which is smaller at the outlet than at the inlet, and a support plate portion (41a, 41b), which includes a proximal end coupled to a transducer (37) of the excitation device and a distal end at which the guide portion is integrally formed, the guide passage including an inlet guide passage (44b), each guide portion is formed into a shape that permits the sound pressure to act on the fiber bundle that passes at least the inlet guide passage of the guide passage from a side corresponding to an opposing surface (45a) that faces the other guide portion and from a side corresponding to a surface (45b) that intersects the opposing surface.
The fiber bundle concentrating apparatus according to claim 1, wherein each guide portion includes a guide surface, which forms the inlet guide passage, the guide surface including the opposing surface and upper and lower surfaces (45b) that intersect the opposing surface and face each other, the guide portion is formed to permit the sound pressure to be applied to the fiber bundle that pass through the inlet guide passage from the side corresponding to the opposing surface and from the sides corresponding to the upper and lower surfaces.
The fiber bundle concentrating apparatus according to claim 1 or 2, wherein each guide portion is formed such that the cross-sectional area of the inlet guide passage is increased toward the inlet section, the guide passage including an outlet guide passage (44a), which is connected to the inlet guide passage, each guide portion including a guide surface, which forms the outlet guide passage, the guide surface including a flat surface (44a1), which extends parallel to the advancing direction of the fiber bundle.
The fiber bundle concentrating apparatus according to claim 3, wherein each guide portion includes an inlet guide passage forming portion (45) having a channel-like cross section, and the width (W) of the inlet guide passage forming portion is greater than the thickness (D) of the support plate portion.
The fiber bundle concentrating apparatus according to claim 3 or 4, wherein each guide portion includes an auxiliary guide surface (44a2), which restricts the fiber bundle passing through the outlet guide passage from moving along the flat surface in a direction perpendicular to the advancing direction of the fiber bundle.
The fiber bundle concentrating apparatus according to any one of claims 1 to 5, wherein the guide member is formed to be symmetrical as viewed from the advancing direction of the fiber bundle.
The fiber bundle concentrating apparatus according to any one of claims 1 to 6, wherein the vibration plate is formed by pressing.