SPINNING MACHINE, FIBER GUIDE, AND AIR-JET SPINNING
DEVICE
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a spinning machine, a fiber guide, and an air-jet spinning device.
2. Description of the Related Art
Conventionally, a technique related to a spinning machine that produces a yarn from a sliver (fiber bundle) is known. The spinning machine includes a pneumatic spinning device having an inlet for the fiber bundle. In spinning machines described in Japanese Unexamined Patent Publication No. 2019-516026 (Patent Document 1) and Japanese Unexamined Patent Publication No. 2007-510822 (Patent Document 2), a sliver is guided to a swirl chamber via an inlet of a spinning nozzle including a fiber guide element. In one aspect described in Patent Document 1, the fiber guide element is arranged to be rotated about a central axis of the spinning nozzle. Specifically, the fiber guide element is arranged on a top roller side of a draft device, or arranged in a state of being rotated by 90 degrees with respect to a nip line of a front roller of the draft device. In the

spinning machine described in Patent Document 2, a turning section is formed by an inclination between a conveyance direction and the fiber guide element.
In the conventional spinning machine including the fiber guide element having the above-described configuration, there is room for improvement in quality of the yarn to be produced, for example, uniformity of the yarn.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a spinning machine, a fiber guide, and an air-jet spinning device capable of improving uniformity of a yarn.
A spinning machine comprises: a draft device including a pair of front rollers and configured to draft a fiber bundle; and an air-jet spinning device configured to produce a yarn by applying whirling airflow to the fiber bundle drafted by the draft device, wherein the air-jet spinning device has a fiber guide including: a front end face facing a nip line of the pair of front rollers; and an inlet opening formed on the front end face, and in the fiber guide, when definition is made to each of: a line segment (E) defined as a width that is a longest part of the inlet opening; a straight line (A)

passing through a center point (H) of the front end face and a midpoint of the line segment (E); a first inclined line (BL) obtained by inclining the straight line (A) by +45 degrees about the center point (H) along the front end face; a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about the center point (H) along the front end face; a first intersection (B) closer to the center point (H) among intersections of the inlet opening and the first inclined line (BL); a second intersection (C) closer to the center point (H) among intersections of the inlet opening and the second inclined line (CL); and a straight line (D) passing through the first intersection (B) and the second intersection (C) , and the fiber guide is arranged with the straight line (D) being inclined by equal to or greater than +10 degrees and equal to or less than +80 degrees, or equal to or less than -10 degrees and equal to or greater than -80 degrees with respect to the nip line, when viewed in an axial direction of the fiber guide.
A spinning machine comprising: a draft device including a pair of front rollers and configured to draft a fiber bundle; and an air-jet spinning device configured to produce a yarn by applying whirling airflow to the

fiber bundle drafted by the draft device, wherein the air-jet spinning device has a fiber guide, and has a spinning chamber internally formed and having a center line, the fiber guide including: a front end face facing a nip line of the pair of front rollers; and an inlet opening formed on the front end face, and in the fiber guide, when definition is made to each of: a line segment (E) defined as a width that is a longest part of the inlet opening; a straight line (A) passing through an intersection (H) of the center line and the front end face and through a midpoint of the line segment (E); a first inclined line (BL) obtained by inclining the straight line (A) by +45 degrees about the intersection (H) along the front end face; a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about the intersection (H) along the front end face; a first intersection (B) closer to the intersection (H) among intersections of the inlet opening and the first inclined line (BL) ; a second intersection (C) closer to the intersection (H) among intersections of the inlet opening and the second inclined line (CL); and a straight line (D) passing through the first intersection (B) and the second intersection (C) , and the fiber guide is arranged with the straight line (D)

being inclined by equal to or greater than +10 degrees and equal to or less than +80 degrees, or equal to or less than -10 degrees and equal to or greater than -80 degrees with respect to the nip line, when viewed in an axial direction of the fiber guide.
A fiber guide applied to an air-jet spinning device, the fiber guide comprises: a front end face; an inlet opening formed on the front end face; and a chamfered section formed on the front end face, wherein at least a part of a boundary between the front end face and the chamfered section forms a chamfering straight line, and when definition is made to each of: a line segment (E) defined as a width that is a longest part of the inlet opening; a straight line (A) passing through a center point (H) of the front end face and a midpoint of the line segment (E); a first inclined line (BL) obtained by inclining the straight line (A) by +45 degrees about the center point (H) of the front end face along the front end face; a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about the center point (H) of the front end face along the front end face; a first intersection (B) closer to the center point (H) among intersections of the front end face and the first inclined line (BL); a second intersection (C)

closer to the center point (H) among intersections of the front end face and the second inclined line (CL) ; and a straight line (D) passing through the first intersection (B) and the second intersection (C), and the chamfering straight line is arranged by being inclined by equal to or greater than +10 degrees and equal to or less than +80 degrees, or equal to or less than -10 degrees and equal to or greater than -80 degrees with respect to the straight line (D), when viewed in an axial direction of the fiber guide.
An air-jet spinning device comprises: a fiber guide having a front end face on which an inlet opening is formed; and a support block configured to support the fiber guide and detachably attached to a main body, wherein the support block has a reference surface facing the main body, and in the fiber guide, when definition is made to each of: a line segment (E) defined as a width that is a longest part of the inlet opening; a straight line (A) passing through a center point (H) of the front end face and a midpoint of the line segment (E); a first inclined line (BL) obtained by inclining the straight line (A) by +45 degrees about the center point (H) along the front end face; a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about

the center point (H) along the front end face; a first intersection (B) closer to the center point (H) among intersections of the inlet opening and the first inclined line (BL); a second intersection (C) closer to the center point (H) among intersections of the inlet opening and the second inclined line (CL); and a straight line (D) passing through the first intersection (B) and the second intersection (C) , and the fiber guide is arranged with the straight line (D) being inclined by equal to or greater than +10 degrees and equal to or less than +80 degrees, or equal to or less than -10 degrees and equal to or greater than -80 degrees with respect to the reference surface of the support block when viewed in an axial direction of the fiber guide.
An air-jet spinning device comprises: a fiber guide having a front end face on which an inlet opening is formed; a support block configured to support the fiber guide; and a turning shaft configured to turnably support the support block, wherein in the fiber guide, when definition is made to each of: a line segment (E) defined as a width that is a longest part of the inlet opening; a straight line (A) passing through a center point (H) of the front end face and a midpoint of the line segment (E) ; a first inclined line (BL) obtained by inclining

the straight line (A) by +45 degrees about the center point (H) along the front end face; a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about the center point (H) along the front end face; a first intersection (B) closer to the center point (H) among intersections of the inlet opening and the first inclined line (BL); a second intersection (C) closer to the center point (H) among intersections of the inlet opening and the second inclined line (CL); and a straight line (D) passing through the first intersection (B) and the second intersection (C), and the fiber guide is arranged with the straight line (D) being inclined by equal to or greater than +10 degrees and equal to or less than +80 degrees, or equal to or less than -10 degrees and equal to or greater than -80 degrees with respect to a turning axis of the turning shaft when viewed in an axial direction of the fiber guide.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view illustrating a spinning
machine according to a first embodiment of the present
invention;
FIG. 2 is a side view illustrating a spinning unit

of the spinning machine of FIG. 1;
FIG. 3 is a perspective view of the air-jet spinning device illustrated in FIG. 1;
FIG. 4 is a cross-sectional view of the air-jet spinning device illustrated in FIG. 1;
FIG. 5(a) is a front view of a fiber guide in FIG. 4, FIG. 5(b) is a plan view of the fiber guide in FIG. 4, FIG. 5(c) is a right side view of the fiber guide in FIG. 4, and FIG. 5(d) is a rear view of the fiber guide in FIG. 4;
FIG. 6 is a view of the fiber guide viewed from an axial direction of the fiber guide, and is a view illustrating an arrangement of the fiber guide with respect to a nip line of a pair of front rollers according to the first embodiment;
FIG. 7 is a view for explaining a definition of an imaginary straight line D in the fiber guide of FIG. 6;
FIGS. 8(a) to 8(g) are views individually illustrating various modifications of the inlet opening;
FIG. 9 is a view illustrating an arrangement of a fiber guide with respect to a nip line of a pair of front rollers in a second embodiment;
FIG. 10 is a view illustrating an arrangement of the fiber guide illustrated in FIG. 9 as viewed from a

rear side;
FIG. 11 is a view for explaining the arrangement of the fiber guide from another viewpoint; and
FIG. 12 is a view illustrating a fiber guide and an arrangement thereof according to an alternative embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS An embodiment of the present invention will be hereinafter described in detail with reference to the accompanying drawings. The same reference numerals are denoted on the same or corresponding portions throughout the drawings, and redundant description will be omitted. As illustrated in FIG. 1, a spinning machine 1 includes a plurality of spinning units 2, a yarn joining cart 3, a doffing cart (not illustrated) , a first end frame 4, and a second end frame 5. The plurality of the spinning units 2 are arranged in a row. Each of the spinning units 2 is configured to produce a yarn Y and to wind the yarn Y around a package P. The yarn joining cart 3 is configured to perform a yarn joining operation in a spinning unit 2 after the yarn Y is cut, or is broken for some reason in such a spinning unit 2. The doffing cart is configured to doff a package P and to

supply a new bobbin 20 to a spinning unit 2 after the package P is fully-wound in such a spinning unit 2. The first end frame 4 accommodates, for example, a collecting device configured to collect a fiber waste, a yarn waste, and the like generated in the spinning units 2.
The second end frame 5 accommodates an air supplying section configured to adjust air pressure of compressed air (air) to be supplied to each section of the spinning machine 1 and to supply the air to each section, a drive motor configured to supply power to each section of the spinning units 2, and the like. The second end frame 5 is provided with a machine control device 100, a touch panel screen 102, and an input key 104. The machine control device 100 is configured to intensively manage and control each section of the spinning machine 1. The touch panel screen 102 can display information relating to set contents and/or a status, or the like of the spinning units 2. An operator can perform a setting operation of the spinning unit 2 by performing an appropriate operation with a button, the input key 104, or the like displayed on the touch panel screen 102.
As illustrated in FIGS. 1 and 2, each spinning unit 2 includes a draft device 6, an air-jet spinning device

(a pneumatic spinning device) 7, a yarn monitoring device 8, a tension sensor 9, a yarn accumulating device 11, a waxing device 12, and a winding device 13 in this order from upstream in a travelling direction of the yarn Y. A unit controller 10 is provided for every predetermined number of the spinning units 2 and is configured to control operations of the spinning units 2.
The draft device 6 is configured to draft a fiber bundle (sliver) S. The draft device 6 includes a pair of back rollers 14, a pair of third rollers 15, a pair of middle rollers 16, and a pair of front rollers 17 in this order from upstream in a travelling direction of the fiber bundle S.
The pair of back rollers 14 include a back bottom roller 14a on a driving side and a back top roller 14b on driven side. The back bottom roller 14a and the back top roller 14b are opposed to each other with a travelling path, on which the fiber bundle S travels, interposed in between. The pair of third rollers 15 include a third bottom roller 15a on a driving side and a third top roller 15b on a driven side. The third bottom roller 15a and the third top roller 15b are opposed to each other with the travelling path, on which the fiber bundle S travels, interposed in between. The

pair of middle rollers 16 include a middle bottom roller 16a on a driving side and a middle top roller 16b on a driven side. The middle bottom roller 16a and the middle top roller 16b are opposed to each other with the travelling path, on which the fiber bundle S travels, interposed in between. The pair of front rollers 17 include a front bottom roller 17a on a driving side and a front top roller 17b on a driven side. The front bottom roller 17a and the front top roller 17b are opposed to each other with the travelling path, on which the fiber bundle S travels, interposed in between.
The back bottom roller 14a, the third bottom roller 15a, the middle bottom roller 16a, and the front bottom roller 17a are rotated by drive motors provided in the spinning unit 2, at mutually different rotational speeds so as to be faster in the downstream side rollers. An apron belt 18a is provided for the middle bottom roller 16a. An apron belt 18b is provided for the middle top roller 16b. The front bottom roller 17a may be driven by a drive motor in the second end frame 5 provided in common for the plurality of spinning units 2.
The back top roller 14b, the third top roller 15b, the middle top roller 16b, and the front top roller 17b are rotatably supported by a draft cradle (not

illustrated) . The back top roller 14b, the third top roller 15b, the middle top roller 16b, and the front top roller 17b are respectively brought into contact with the back bottom roller 14a, the third bottom roller 15a, the middle bottom roller 16a, and the front bottom roller 17a at a predetermined pressure, to be driven and rotated
The air-jet spinning device 7 produces the yarn Y by twisting a fiber bundle F drafted by the draft device 6, with whirling airflow. Details of the air-jet spinning device 7 will be described later.
The yarn monitoring device 8 is configured to monitor information on the travelling yarn Y between the air-jet spinning device 7 and the yarn accumulating device 11, and to detect presence or absence of a yarn defect based on the information acquired by the monitoring. When detecting the yarn defect, the yarn monitoring device 8 transmits a yarn defect detection signal to the unit controller 10. The yarn monitoring device 8 detects a thickness abnormality of the yarn Y and/or a foreign substance included in the yarn Y, for example, as the yarn defect. The yarn monitoring device 8 also detects a yarn breakage or the like. The tension sensor 9 is configured to measure tension of the travelling yarn Y between the air-jet spinning device 7

and the yarn accumulating device 11, and to transmit a tension measurement signal to the unit controller 10. When the unit controller 10 determines a presence of an abnormality based on a detection result of the yarn monitoring device 8 and/or the tension sensor 9, the yarn Y is cut in the spinning unit 2. Specifically, by stopping air supply to the air-jet spinning device 7 to interrupt the production of the yarn Y, the yarn Y is cut. Alternatively, the yarn Y may be cut with a cutter separately provided.
The waxing device 12 is configured to apply wax to the yarn Y between the yarn accumulating device 11 and the winding device 13.
The yarn accumulating device 11 accumulates the yarn Y between the air-jet spinning device 7 and the winding device 13. The yarn accumulating device 11 includes a yarn accumulating roller configured to accumulate the yarn Y by winding the yarn Y around an outer peripheral surface. The yarn accumulating device 11 has a function of stably withdrawing the yarn Y from the air-jet spinning device 7, a function of preventing the yarn Y from slackening by accumulating the yarn Y fed from the air-jet spinning device 7 at the time of the yarn joining operation or the like by the yarn

joining cart 3, and a function of preventing variation in the tension of the yarn Y at downstream of the yarn accumulating device 11 from being propagated to the air-jet spinning device 7.
The winding device 13 is configured to wind the yarn Y around the bobbin 20 to form the package P. The winding device 13 includes a cradle arm 21, a winding drum 22 and a traverse guide 23. The cradle arm 21 is configured to rotatably support the bobbin 20. The cradle arm 21 is swingably supported by a supporting shaft 24 and is configured to bring a surface of the bobbin 20 or a surface of the package P into contact with a surface of the winding drum 22 under appropriate pressure. A drive motor (not illustrated) provided in the second end frame 5 is configured to simultaneously drive the winding drums 22 each provided in the plurality of the spinning units 2. Accordingly, in each spinning unit 2, the bobbin 20 or the package P is rotated in a winding direction. The traverse guide 23 of each spinning unit 2 is provided on a shaft 25 shared by the plurality of the spinning units 2. By the drive motor in the second end frame 5 driving the shaft 25 to reciprocate in a rotational axis direction of the winding drum 22, the traverse guide 23 traverses the yarn Y in a predetermined width with

respect to the rotating bobbin 20 or package P.
After the yarn Y is cut, or is broken for some reason in a spinning unit 2, the yarn joining cart 3 travels to such a spinning unit 2 to perform the yarn joining operation. The yarn joining cart 3 includes a yarn joining device 26, a suction pipe 27 and a suction mouth 28. The suction pipe 27 is swingably supported by a supporting shaft 27a, and is configured to catch the yarn Y from the air-jet spinning device 7 and to guide the caught yarn Y to the yarn joining device 26. The suction mouth 28 is swingably supported by a supporting shaft 27b, and is configured to catch the yarn Y from the winding device 13 and to guide the caught yarn Y to the yarn joining device 26. The yarn joining device 26 joins the guided yarns Y together. The yarn joining device 26 is a splicer using compressed air, a knotter that joins the yarns Y together in a mechanical manner, or the like.
When the yarn joining cart 3 performs the yarn joining operation, the package P is rotated in an unwinding direction (reversely rotated). At this time, the cradle arm 21 is moved by an air cylinder (not illustrated) such that the package P is located away from the winding drum 22, and the package P is reversely

rotated by a reversely-rotating roller (not illustrated) provided in the yarn joining cart 3.
Next, the air-jet spinning device 7 will be described in detail with reference to FIGS. 3 and 4. In FIGS. 3 and 4 and some subsequent drawings, an xyz orthogonal coordinate system is also illustrated for reference of a position or an arrangement of members or components. The xyz orthogonal coordinate system illustrated in FIG. 3 is illustrated with a nozzle house 30 as a reference instead of a hollow guide shaft body 34.
As illustrated in FIGS. 3 and 4, the air-jet spinning device 7 includes the nozzle house 30 and the hollow guide shaft body 34. The nozzle house 30 includes a nozzle holder (supporting block) 37, a fiber guide 31, a spinning chamber 32, and a nozzle block 38. The hollow guide shaft body 34 includes a yarn passage 35 and a second nozzle 36. An operation of the air-jet spinning device 7 is controlled by the unit controller 10. The second nozzle 36 may not be provided.
The fiber guide 31 and the nozzle block 38 are fixed to the nozzle holder 37, which is a main body of the nozzle house 30. The fiber guide 31 and the nozzle block 38 are fixed to the nozzle holder 37 by, for

example, a nozzle cap 39. In the nozzle house 30, the fiber guide 31 and the nozzle block 38 are configured as separate members, but the fiber guide 31 and the nozzle block 38 may be configured integrally or from one member. As illustrated in FIG. 4, the fiber guide 31 is a member configured to guide the drafted fiber bundle F toward inside of the air-jet spinning device 7. The fiber guide 31 includes a fiber introduction path 31a formed internally, a needle-shaped member 31b, a front end face 31c, and a rear end face 31d. The fiber guide 31 has an inlet opening 31e (see FIG. 5(a)) of the fiber introduction path 31a and an outlet opening 31f (see FIG. 5(d)) of the fiber introduction path 31a. The inlet opening 31e is formed on the front end face 31c, and the outlet opening 31f is formed on the rear end face 31d. The inlet opening 31e is an intersection line between the fiber introduction path 31a and the front end face 31c. The outlet opening 31f is an intersection line between the fiber introduction path 31a and the rear end face 31d. The "intersection line" is a connection line connecting a certain face (the front end face 31c or the rear end face 31d) and a wall surface forming a certain space (the fiber introduction path 31a). The fiber guide 31 guides the fiber bundle F into the spinning chamber

32 by the fiber introduction path 31a that is connected to the spinning chamber 32 . When the needle-shaped member 31b is provided, the fiber bundle F is guided into the spinning chamber 32 through the needle-shaped member 31b.
The nozzle block 38 includes first nozzles 33. The nozzle block 38 and the rear end face 31d of the fiber guide 31 form the spinning chamber 32. That is, the spinning chamber 32 is formed inside the air-jet spinning device 7. The first nozzles 33 are arranged around the spinning chamber 32 (a path where the fiber bundle F travels). The air-jet spinning device 7 injects air from the first nozzles 33 into the spinning chamber 32, and applies whirling airflow on the fiber bundle F in the spinning chamber 32 . With the whirling airflow, each fiber end of a plurality of fibers that form the fiber bundle F is reversed and whirled.
The hollow guide shaft body 34 is a cylindrical shaped member, and the yarn passage 35 is formed inside thereof. The hollow guide shaft body 34 guides the produced yarn Y toward outside of the air-jet spinning device 7.
When performing the yarn discharge spinning for starting the spinning operation, the air-jet spinning

device 7 injects air from the second nozzle 36 into the yarn passage 35 to generate whirling airflow in the yarn passage 35. A direction of the whirling airflow generated in the yarn passage 35 is opposite to a direction of whirling airflow in the spinning chamber 32. This causes the fiber bundle F to be introduced from the draft device 6 to the air-jet spinning device 7, and the production of the yarn Y is started.
The needle-shaped member 31b may be omitted, and a downstream end of the fiber guide 31 may have the function of the needle-shaped member 31b.
When the yarn Y is connected by piecing, air is injected from the second nozzle 36 to reversely feed the yarn Y from the package P into the air-jet spinning device 7.
As illustrated in FIG. 3, in the air-jet spinning device 7, the nozzle house 30 is detachably attached to a main body 40. The air-jet spinning device 7 includes the nozzle block 38 configured to support the fiber guide 31, the nozzle holder 37 configured to support the fiber guide 31 and the nozzle block 38, and the nozzle house 30 detachably attached to the main body 40. The nozzle house 30 is connected to and fixed to the main body 40 with a bolt Bl or the like. The main body 40 is provided

to be swingable with a base end section 41 as a fulcrum. The air-jet spinning device 7 includes a support section 50 configured to support the hollow guide shaft body 34. The support section 50 is provided to be swingable with a base end section 51 as a fulcrum. The base end section 41 of the main body 40 and the base end section 51 of the support section 50 are turnably attached with each other with a turning shaft 43 as a fulcrum. The turning shaft 43 is fixed to a machine frame la (see FIG. 1). The support section 50 swings in a direction approaching the main body 40 and a direction away from the main body 40 with the turning shaft 43 as a fulcrum, by a driving section such as an air cylinder (not illustrated). The support section 50 is fixed to the machine frame la via a spring member 44, to be urged in a direction approaching the main body 40.
A configuration of the fiber guide 31 and an arrangement thereof will be described in detail with reference to FIGS. 5 and 6. As illustrated in FIGS. 5(a) and 6, the fiber guide 31 has, for example, a circular front end face 31c. For example, the fiber guide 31 having a cylindrical shape as a whole has an axis 31L. The axis 31L is a center line of the spinning chamber 32. The axis 31L of the fiber guide 31 passes

through a center point H of the front end face 31c. A y-direction illustrated in FIG. 6 is parallel to the axis 31L. As illustrated in FIG. 5(c), on an outer peripheral surface of the fiber guide 31 having a cylindrical shape as a whole, a groove may be formed in a circumferential direction.
The fiber guide 31 includes, for example, a first chamfered section 61 and a second chamfered section 62 formed on the front end face 31c. Positions and sizes of the first chamfered section 61 and the second chamfered section 62 are not particularly limited, but in the present embodiment, the first chamfered section 61 and the second chamfered section 62 are formed at different positions and are located away from each other. Between the first chamfered section 61 and the second chamfered section 62, the inlet opening 31e is arranged. A boundary between the front end face 31c and the first chamfered section 61 forms a first chamfering straight line J. The front end face 31c and the first chamfered section 61 are connected by the first chamfering straight line J. The first chamfering straight line J is formed from one peripheral edge (first peripheral edge) 71a to another peripheral edge (second peripheral edge) 71b of the front end face 31c. A boundary between the front

end face 31c and the second chamfered section 62 forms a second chamfering straight line Jl. The front end face 31c and the second chamfered section 62 are connected by the second chamfering straight line Jl. The second chamfering straight line Jl is formed from one peripheral edge (first peripheral edge) 72a to another peripheral edge (second peripheral edge) 72b of the front end face 31c.
The first chamfering straight line J and the second chamfering straight line Jl are chords on the front end face 31c. The first chamfering straight line J corresponding to the boundary between the front end face 31c and the first chamfered section 61 is, for example, parallel to the second chamfering straight line Jl corresponding to the boundary between the front end face 31c and the second chamfered section 62. As illustrated in FIGS. 5(b) and 5(c), the first chamfered section 61 and the second chamfered section 62 may have the same size, or may have different sizes. The first chamfered section 61 arranged closer to the inlet opening 31e may be smaller than the second chamfered section 62.
The inlet opening 31e of the fiber guide 31 is, for example, a long hole extending long in a certain direction. The inlet opening 31e extends, for example,

along the first chamfering straight line J. The inlet opening 31e may be parallel to the first chamfering straight line J and/or the second chamfering straight line Jl. That is, either the first chamfering straight line J or the second chamfering straight line Jl may not be parallel to the inlet opening 31e.
FIG. 6 illustrates an arrangement of the draft device 6 and the fiber guide 31 in the air-jet spinning device 7. In FIG. 6, a nip line L where the front top roller 17b and the front bottom roller 17a are in contact with each other is indicated by an imaginary line. An x-direction illustrated in FIG. 6 is parallel to the nip line L. The front end face 31c of the fiber guide 31 faces the nip line L. As illustrated in FIG. 6, when viewed from the axis 31L of the fiber guide 31, the inlet opening 31e is inclined clockwise with respect to the nip line L. An inclination angle 9 is an acute angle. Although not illustrated, a plurality of grooves parallel to a roller shaft may be formed on the front bottom roller 17a.
In order to clearly describe an arrangement
(layout) of the fiber guide 31, imaginary straight lines
and imaginary points in the fiber guide 31 are defined.
As illustrated in FIG. 7, a line segment E is defined as

a width that is a longest part of the inlet opening 31e. A straight line A is defined as a straight line passing through the center point H of the front end face 31c and a midpoint of the line segment E. A first inclined line BL is defined as a line obtained by inclining the straight line A by +45 degrees about the center point H of the front end face 31c along the front end face 31c. A second inclined line CL is defined as a line obtained by inclining the straight line A by -45 degrees about the center point H of the front end face 31c along the front end face 31c. A first intersection B is defined as a point closer to the center point H among intersections of the inlet opening 31e and the first inclined line BL. A second intersection C is defined as a point closer to the center point H among intersections of the inlet opening 31e and the second inclined line CL. A reference straight line D is defined as a straight line passing through the first intersection B and the second intersection C. These straight lines and points can be defined in the fiber guide of any aspect, without limiting to the inlet opening 31e of the fiber guide 31 of the present embodiment.
As illustrated in FIG. 6, the fiber guide 31 is arranged such that the reference straight line D is

inclined at the inclination angle 9 of equal to or greater than +10 degrees and equal to or less than +80 degrees with respect to the nip line L, when the front end face 31c is viewed from the axis 31L direction. In the present specification, the inclination angle 9 is defined as an angle formed between the nip line L and the reference straight line D and having an absolute value of equal to or less than 180 degrees. The inclination angle 9 is set such that a clockwise inclination has a positive angle and a counterclockwise inclination has a negative angle, when the front end face 31c is viewed from the axis 31L direction. For example, a reference direction (orientation) of the fiber guide 31 may be defined by a direction (orientation) of virtually, when all or half or more than half of the inlet opening 31e is arranged closer to the front top roller 17b side (the driven roller side of the pair of front rollers 17) than the nip line L, and the reference straight line D is parallel to the nip line L. In FIG. 6, the inlet opening 31e of the fiber guide 31 located in the reference direction and the reference straight line D are indicated by imaginary lines. The actual direction of the fiber guide 31 attached to the nozzle cap 39 is rotated from the

reference direction in the same direction as the above-described inclination angle 9.
The straight line A may not be defined with the center point H of the front end face 31c as a reference. In another viewpoint, the straight line A may be defined as a straight line passing through an intersection of the axis 31L, which is the center line of the spinning chamber 32, and the front end face 31c, and through a midpoint of the line segment E. In the present embodiment, the intersection of the axis 31L and the front end face 31c coincides with the center point H of the front end face 31c. However, when the front end face 31c is not a perfect circle (in an outer shape when the chamfered section is not considered) and a center thereof is not able to be defined, the straight line A may be defined with the intersection of the axis 31L and the front end face 31c as a reference.
Preferably, the fiber guide 31 is arranged such that the reference straight line D is inclined at an inclination angle 9 of equal to or greater than +15 degrees and equal to or less than +60 degrees with respect to the nip line L when viewed in the axis 31L direction. Still more preferably, the fiber guide 31 is arranged such that the reference straight line D is

inclined at an inclination angle 9 of equal to or greater than + 20 degrees and equal to or less than +50 degrees with respect to the nip line L when viewed in the axis 31L direction.
When viewed in the axis 31L direction, the reference straight line D is inclined inversely (oppositely) with respect to a whirling direction of whirling airflow generated in the spinning chamber 32 . For example, the whirling airflow is directed counterclockwise when viewed in the axis 31L direction, but the reference straight line D of the inlet opening 31e is inclined clockwise with respect to the nip line L.
At the inlet opening 31e, a length of the line segment E (that is, a maximum width) is equal to or greater than 2 mm and equal to or less than 14 mm, and a maximum height Z is equal to or greater than 0.3 mm and equal to or less than 6 mm. The maximum height Z can be defined at a position having a maximum height, the position being located in a width direction of the inlet opening 31e. The height of the inlet opening 31e is a length in a direction of the straight line A. As illustrated in FIG. 7, when the inlet opening 31e has a uniform height, the maximum height Z may be a height

(constant and unchanged) at any position. Preferably, the length of the line segment E is equal to or greater than 4 mm and equal to or less than 10 mm, and the maximum height Z is equal to or greater than 0.5 mm and equal to or less than 4 mm.
At the inlet opening 31e, a length G from the center point H of the front end face 31c to the reference straight line D is equal to or greater than 0.5 mm and equal to or less than 4.0 mm. Preferably, the length G is equal to or greater than 0.5 mm and equal to or less than 2.5 mm. The length G may not be defined with the center point H of the front end face 31c as a reference. In another viewpoint, the length G may be defined as a length from the intersection of the axis 31L and the front end face 31c to the reference straight line D.
As illustrated in FIG. 5(d), the outlet opening 31f of the fiber guide 31 includes a linear base 31k. The base 31k of the outlet opening 31f is, for example, parallel to the reference straight line D of the inlet opening 31e. Therefore, when viewed in the axis 31L direction, the base 31k of the outlet opening 31f is also inclined with respect to the nip line L. An inclination angle of the base 31k with respect to the nip line L may be the same as or different from the

above-described inclination angle 9.
In the spinning machine 1 including the air-jet spinning device 7 according to the present embodiment, since the reference straight line D at the inlet opening 31e of the fiber guide 31 is provided to be inclined at the above-described inclination angle 9 with respect to the nip line L of the pair of front rollers 17, the fiber bundle F can be converged with the fiber bundle F being appropriately bent in the fiber guide 31. As a result, uniformity of the yarn Y can be improved.
According to the air-jet spinning device 7 of the spinning machine 1, the fiber bundle F can be successfully converged, and an inter-fiber binding property can be enhanced. Enhancing the inter-fiber binding property also makes it possible to reduce loss of fibers in a section between the pair of front rollers 17 and a distal end of the hollow guide shaft body 34. Conventionally, in order to enhance the inter-fiber binding property, it is conceivable as a solution to increase bending given to the fiber bundle or to converge the fiber bundle. Increasing the bending given to the fiber bundle can be realized by increasing a height of (separating from the axis) a position of the inlet opening of the fiber guide. Furthermore, in order to

enhance the convergence of the fiber bundle, two types of solutions can be assumed: converging the fiber bundle S in the draft device 6, or converging the fiber bundle F with the fiber guide. However, when the fiber bundle S is converged by the draft device 6, poor drafting and/or slippage of the draft roller may occur when a fiber amount is large. Further, in order to converge the fiber bundle F with the fiber guide, it is necessary to greatly reduce a cross-sectional area of the inlet opening. Greatly reducing the cross-sectional area of the inlet opening of the fiber guide may deteriorate a fiber bundle suction performance of the air-jet spinning device. Therefore, it has been difficult to increase the convergence of the fiber bundle F entering the fiber guide without deteriorating the performance of the fiber guide. However, according to the present embodiment, the convergence of the fiber bundle F entering the fiber guide 31 is improved without deterioration in the performance of the fiber guide 31.
With the inclination of the reference straight line D as in the fiber guide 31 of the present embodiment, the fiber bundle F can be converged near the inlet opening 31e. This has an advantageous effect described below than converging the fiber bundle F near the outlet.

That is, the convergence section becomes long, and the fiber guide 31 can have a simple shape. Therefore, the fiber guide 31 is easily manufactured. According to the fiber guide 31 of the present embodiment, the fiber bundle F can be easily converged without a great change (for example, without narrowing down) in the cross-sectional area of the fiber introduction path 31a.
In the fiber guide 31 of the present embodiment, the length G from the center point H of the front end face 31c to the reference straight line D, or the length G from the intersection of the axis 31L and the front end face 31c to the reference straight line D is equal to or greater than 0.5 mm and equal to or less than 4.0 mm, preferably equal to or greater than 0.5 mm and equal to or less than 2.5 mm. The length G from the center point H of the front end face 31c to the reference straight line D is a distance between the center point H and the reference straight line D. The length G from the intersection of the axis 31L and the front end face 31c to the reference straight line D is a distance between the intersection of the axis 31L and the front end face 31c and the reference straight line D. The distance between a point and a straight line means a shortest distance. For example, a length from the center

point H to the first intersection B or the second intersection C is not the length G (obviously longer than the length G) . According to the above-described configuration, the fiber bundle F can be spun after an appropriate tension is applied to the fiber bundle F, and the quality of the yarn Y is stabilized. A situation may have conventionally occurred in which a tension is not able to be applied to the fiber bundle F and the fiber falls off, or in which the tension is excessively applied and the fiber is difficult to be reversed, but such a situation is avoided.
When viewed in the axis 31L direction of the fiber guide 31, the reference straight line D is inclined at an inclination angle 9 of equal to or greater than +15 degrees and equal to or less than +60 degrees with respect to the nip line L. Thus, the improvement of the uniformity of the yarn Y can be more suitably achieved.
When viewed in the axis 31L direction of the fiber guide 31, if the reference straight line D is inclined at an inclination angle 9 of equal to or greater than +20 degrees and equal to or less than +50 degrees with respect to the nip line L, the improvement of the uniformity of the yarn Y can be even more suitably achieved.

The reference straight line D is inclined oppositely with respect to the whirling direction of the whirling airflow in the spinning chamber 32. This causes the whirling airflow to act on the fiber bundle F in a direction of running up a wall surface of the fiber guide 31. Therefore, tension can be easily applied to the fiber bundle F.
At the inlet opening 31e of the fiber guide 31, the length of the line segment E is equal to or greater than 2 mm and equal to or less than 14 mm, preferably equal to or greater than 4 mm and equal to or less than 10 mm, and the maximum height Z is equal to or greater than 0.3 mm and equal to or less than 6 mm, preferably equal to or greater than 0.5 mm and equal to or less than 4 mm. According to the above-described configuration, a size and a cross-sectional area of the inlet opening 31e are appropriately set, and the fiber bundle F can be appropriately converged while a suction flow rate is sufficiently maintained.
The first chamfering straight line J is formed from the peripheral edge 71a to the peripheral edge 71b of the front end face 31c. The second chamfering straight line Jl is formed from the peripheral edge 72a to the peripheral edge 72b of the front end face 31c. According

to the configuration in which the straight part is long, visibility of the fiber guide 31 for a worker is enhanced This may improve positioning accuracy of the fiber guide 31 with respect to the nip line L of the pair of front rollers 17.
The first chamfered section 61 and the second chamfered section 62 are formed on the front end face 31c, and the first chamfering straight line J and the second chamfering straight line Jl are parallel to each other. This allows the fiber guide 31 to be arranged close to the pair of front rollers 17.
One embodiment of the present invention has been described, but the present invention is not limited to the above-described embodiment. The above-described embodiment and the following alternative embodiments may be appropriately combined.
In the above-described embodiment, the fiber guide 31 has been arranged such that the reference straight line D is inclined at the inclination angle 9 of equal to or greater than +10 degrees and equal to or less than +80 degrees with respect to the nip line L when viewed from the axis 31L direction. However, the fiber guide 31 may be arranged such that the reference straight line D is inclined at an inclination angle 9 of equal to or

less than -10 degrees and equal to or greater than -80 degrees with respect to the nip line L when viewed in the axis 31L direction. In this case, preferably, the fiber guide 31 is arranged such that the reference straight line D is inclined at an inclination angle 9 of equal to or less than -15 degrees and equal to or greater than -60 degrees with respect to the nip line L when viewed in the axis 31L direction. Still more preferably, the fiber guide 31 is arranged such that the reference straight line D is inclined at an inclination angle 9 of equal to or less than -20 degrees and equal to or greater than -50 degrees with respect to the nip line L when viewed in the axis 31L direction. Even with such a configuration, the fiber bundle F can be converged with the fiber bundle F being appropriately bent in the fiber guide 31. As a result, uniformity of the yarn Y can be improved.
The shape of the inlet opening 31e is not limited to the long hole shape described in the above-described embodiment. For example, the inlet opening 31e may have various shapes illustrated in FIGS. 8(b) to 8(g) . As illustrated in FIG. 8(b), the fiber guide may have an inlet opening 80B that is a rectangular long hole extending in the x-direction. As illustrated in FIG.

8(c), the fiber guide may have an inlet opening 80C that is an elliptical elongated hole extending in the x-direction. As illustrated in FIG. 8(d), the fiber guide may have an inlet opening 80D that is a long hole extending in the x-direction and including a linear base and a top having a partial arc shape. As illustrated in FIG. 8(e), the fiber guide may have an inlet opening 80E that is a rectangular long hole similarly to the inlet opening 80B but includes, for example, a semicircular protrusion (recess on the front end face 31c) on a base. As illustrated in FIG. 8(f), the fiber guide may have an inlet opening 80F that is a rectangular long hole similarly to the inlet opening 80B but includes, for example, a semicircular recess (protrusion on the front end face 31c) on a base. As illustrated in FIG. 8(g), the fiber guide may have an inlet opening 80G that is a pentagonal long hole extending in the x-direction and including a linear top and a base including two sides intersecting at a predetermined angle of equal to or greater than 90 degrees and less than 180 degrees. In any of these shapes, the straight line D is defined in a similar manner as in the above-described embodiment, and the straight line D is arranged to be inclined within a similar range as in the above-described embodiment.

In the above-described embodiment, the inlet opening 31e (more specifically, the reference straight line D) has been parallel to the first chamfering straight line J and/or the second chamfering straight line Jl. However, as illustrated in FIG. 9, when viewed in the axis 31L direction of the fiber guide 31, the first chamfering straight line J and/or the second chamfering straight line Jl may be arranged so as to be inclined at an inclination angle of equal to or greater than +10 degrees and equal to or less than +80 degrees with respect to the reference straight line D. Even in this case, the reference straight line D is inclined at an inclination angle 9 of equal to or greater than +10 degrees and equal to or less than +80 degrees with respect to the nip line L when viewed in the axis 31L direction. When viewed in the axis 31L direction of the fiber guide 31, the first chamfering straight line J and/or the second chamfering straight line Jl may be arranged so as to be inclined at an inclination angle of equal to or less than -10 degrees and equal to or greater than -80 degrees with respect to the reference straight line D.
This fiber guide 31 can also converge the fiber bundle F while bending the fiber bundle F. As a result,

uniformity of the yarn Y can be improved.
Further, as illustrated in FIG. 10, the fiber guide 31 may include the outlet opening 31f formed on the rear end face 31d, and the outlet opening 31f may include the linear base 31k. The base 31k of the outlet opening 31f may be provided to be inclined with respect to the reference straight line D of the inlet opening 31e. In this case, the fiber bundle F can be guided while being further converged.
When viewed in the axis 31L direction, the reference straight line D of the inlet opening 31e and the base 31k of the outlet opening 31f are not parallel to each other, and respective extension lines intersect each other. An angle formed by the reference straight line D and the base 31k is equal to or greater than 0 degrees. In this case, further convergence of the fiber bundle F described above is achieved in a more preferable state.
The reference indicating the inclination angle 9 of the reference straight line D does not need to be the nip line L described above. As illustrated in FIG. 11, a reference surface R of the nozzle house 30 detachably attached to the main body 40 may be a reference surface (reference line) of the inclination angle 9, instead of

the nip line L. The reference surface R faces the main body 40. Alternatively, the nozzle house 30 may not be detachably attached to the main body 40 but may be integrally formed. In this case, a turning axis 43L (see also FIG. 3) of the turning shaft 43 turnably supporting the nozzle house 30 may be set as the reference line of the inclination angle 9, instead of the nip line L.
As illustrated in FIG. 12, the first chamfered section 61, the second chamfered section 62, and a third chamfered section 63 may be formed on the front end face 31c, and the second chamfering straight line Jl and the third chamfering straight line J2 may be connected at a connection point PJ located within a plane excluding a peripheral edge of the front end face 31c. The second chamfering straight line Jl is formed from the peripheral edge 72a of the front end face 31c to the connection point PJ. The third chamfering straight line J2 is formed from a peripheral edge 73a of the front end face 31c to the connection point PJ.
The third chamfering straight line J2 is arranged parallel to the reference straight line D. Since the front end face 31c of the fiber guide 31 has a partial line parallel to the reference straight line D, it is easy to position the fiber guide 31 with respect to the

nip line L. Note that the second chamfering straight line Jl may correspond to a "chamfering straight line" described in the claims, and the third chamfering straight line J2 may correspond to a "third chamfering straight line" described in the claims. In the aspect illustrated in FIG. 12, the first chamfered section 61 may be omitted, and the first chamfering straight line J may not be formed.
A number and/or a shape of the chamfered sections are not particularly limited to the above-described embodiment and alternative embodiments. The front end face 31c may not be provided with any chamfered section, and may be provided with four or more chamfered sections. When four or more chamfered sections are provided, the number of chamfered sections (including 0) may be different on each side with respect to the center point H of the front end face 31c.
The inlet opening 31e may be formed to include at least one chamfered section.
A connecting part between the inlet opening 31e and the front end face 31c does not need to be at a right angle when viewed in a direction parallel to the axis 31L, and chamfering and/or an R may be formed on at least a part of the connecting part.

A shape of the fiber introduction path 31a following the inlet opening 31e is not particularly limited. A fiber guiding surface of the fiber introduction path 31a may include any one or more of a flat surface, at least one twisted surface, and a bent portion.
In the above-described embodiment, a mode in which the draft device 6 includes the pair of back rollers 14, the pair of third rollers 15, the pair of middle rollers 16, and the pair of front rollers 17 has been described by way of example. However, one or more pairs of rollers may be provided on an upstream side of the pair of back rollers 14. Further, the pair of front rollers (pair of rollers arranged at a position closest to the air-jet spinning device 7 in a conveyance path of the fiber bundle F) may be configured as a part of another device. For example, the spinning unit 2 may include a supplying device configured to supply the fiber bundle F drafted by the draft device 6 to the air-jet spinning device 7, and the pair of front rollers 17 may be included in a part of the supplying device. The pair of front rollers 17 may be included in the draft device 6 configured to draft the fiber bundle S or the supply device configured to supply the fiber bundle F to the air-jet spinning

device 7, or may be provided alone without being included in other devices.
The air-jet spinning device 7 may not be turnably attached with the turning shaft 43 as a fulcrum.
In the spinning unit 2, the yarn accumulating device 11 has a function of withdrawing the yarn Y from the air-jet spinning device 7, but the yarn Y may be withdrawn from the air-jet spinning device 7 with a delivery roller and a nip roller. In a case of withdrawing the yarn Y from the air-jet spinning device 7 with the delivery roller and the nip roller, a slack tube using suction airflow or a mechanic compensator, or the like may be provided instead of the yarn accumulating device 11 or in addition to the yarn accumulating device 11.
In the spinning unit 2, instead of the configuration in which two yarn ends are connected by the yarn joining device 26, the yarn Y from the air-jet spinning device 7 and the yarn Y of the package P may be connected (subjected to piecing) by inserting the yarn Y from the package P into the air-jet spinning device 7 and starting a draft operation of the draft device 6 and a spinning operation of the air-jet spinning device 7.
In the spinning machine 1, each device is arranged

such that the yarn Y supplied at an upper side is wound at a lower side in a direction of a machine height. However, each device may be arranged such that the yarn supplied at the lower side is wound at the upper side.
In the spinning machine 1, at least one of the bottom rollers in the draft device 6, and the traverse guide 23 are driven by power from the second end frame 5 (that is, in common with the plurality of spinning units 2) . However, each section (for example, a draft device, a spinning device, a winding device, or the like) of the spinning unit 2 may be driven independently for each spinning unit 2.
In the travelling direction of the yarn Y, the tension sensor 9 may be arranged upstream of the yarn monitoring device 8. The unit controller 10 may be provided for every spinning unit 2. In the spinning unit 2, the waxing device 12, the tension sensor 9, and the yarn monitoring device 8 may be omitted. When the wax is not applied to the yarn Y, the wax alone may be removed from the waxing device 12 without omitting the waxing device 12.
FIG. 1 illustrates that the spinning machine 1 winds a cheese package P, but the spinning machine 1 can also wind a conical package P. In a case of the conical

package, slackening of the yarn Y occurs by traversing of the yarn Y, but the slackening can be absorbed with the yarn accumulating device 11. A material and a shape of each component are not limited to the above-described material and shape, and various materials and shapes can be adopted.
A spinning machine according to one aspect of the present invention includes: a draft device including a pair of front rollers and configured to draft a fiber bundle; and an air-jet spinning device configured to produce a yarn by applying whirling airflow to the fiber bundle drafted by the draft device. The air-jet spinning device has a fiber guide including: a front end face facing a nip line of the pair of front rollers; and an inlet opening formed on the front end face. In the fiber guide, when definition is made to each of: a line segment (E) defined as a width that is a longest part of the inlet opening; a straight line (A) passing through a center point (H) of the front end face and a midpoint of the line segment (E); a first inclined line (BL) obtained by inclining the straight line (A) by +45 degrees about the center point (H) along the front end face; a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about the center point (H) along

the front end face; a first intersection (B) closer to the center point (H) among intersections of the inlet opening and the first inclined line (BL) ; a second intersection (C) closer to the center point (H) among intersections of the inlet opening and the second inclined line (CL) ; and a straight line (D) passing through the first intersection (B) and the second intersection (C), the fiber guide is arranged such that the straight line (D) is inclined by equal to or greater than +10 degrees and equal to or less than +80 degrees, or equal to or less than -10 degrees and equal to or greater than -80 degrees with respect to the nip line, when viewed in an axial direction of the fiber guide.
A spinning machine according to another aspect of the present invention includes: a draft device including a pair of front rollers and configured to draft a fiber bundle; and an air-jet spinning device configured to produce a yarn by applying whirling airflow to the fiber bundle drafted by the draft device. The air-jet spinning device has a fiber guide including: a front end face facing a nip line of the pair of front rollers; and an inlet opening formed on the front end face, and has a spinning chamber internally formed and having a center line. In the fiber guide, when definition is made to

each of: a line segment (E) defined as a width that is a longest part of the inlet opening; a straight line (A) passing through an intersection (H) of the center line and the front end face and through a midpoint of the line segment (E); a first inclined line (BL) obtained by inclining the straight line (A) by +45 degrees about the intersection (H) along the front end face; a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about the intersection (H) along the front end face; a first intersection (B) closer to the intersection (H) among intersections of the inlet opening and the first inclined line (BL) ; a second intersection (C) closer to the intersection (H) among intersections of the inlet opening and the second inclined line (CL) ; and a straight line (D) passing through the first intersection (B) and the second intersection (C), the fiber guide is arranged such that the straight line (D) is inclined by equal to or greater than +10 degrees and equal to or less than +80 degrees, or equal to or less than -10 degrees and equal to or greater than -80 degrees with respect to the nip line, when viewed in an axial direction of the fiber guide.
In these spinning machines, the straight line (D) at the inlet opening of the fiber guide is arranged to

be inclined at the above-described inclination angle with respect to the nip line of the pair of front rollers Therefore, the fiber bundle can be converged with the fiber bundle being bent at the inlet opening of the fiber guide. As a result, uniformity of the yarn can be improved.
A length (G) from the center point (H) of the front end face to the straight line (D) may be equal to or greater than 0.5 mm and equal to or less than 4.0 mm, and preferably equal to or greater than 0.5 mm and equal to or less than 2.5 mm. In this case, the fiber bundle can be spun after an appropriate tension is applied to the fiber bundle, and the quality of the yarn is stabilized.
A length (G) from the intersection (H) of the center line and the front end face to the straight line (D) may be equal to or greater than 0.5 mm and equal to or less than 4.0 mm, and preferably equal to or greater than 0.5 mm and equal to or less than 2.5 mm. In this case, the fiber bundle can be spun after an appropriate tension is applied to the fiber bundle, and the quality of the yarn is stabilized.
The fiber guide may be arranged such that the straight line (D) is inclined by equal to or greater

than +15 degrees and equal to or less than +60 degree, or equal to or less than -15 degrees and equal to or greater than -60 degrees with respect to the nip line when viewed in the axial direction of the fiber guide. In this case, the improvement of the uniformity of the yarn can be more suitably achieved.
The fiber guide may be arranged such that the straight line (D) is inclined by equal to or greater than +20 degrees and equal to or less than +50 degrees, or equal to or less than -20 degrees and equal to or greater than -50 degrees with respect to the nip line when viewed in the axial direction of the fiber guide. In this case, the improvement of the uniformity of the yarn can be even more suitably achieved.
The straight line (D) may be inclined inversely with respect to a whirling direction of the whirling airflow. In this case, the whirling airflow acts on the fiber bundle in a direction of running up a wall surface of the fiber guide. Tension can be easily applied to the fiber bundle.
At the inlet opening of the fiber guide, a length of the line segment (E) may be equal to or greater than 2 mm and equal to or less than 14 mm, preferably equal to or greater than 4 mm and equal to or less than 10 mm,

and a maximum height (Z) may be equal to or greater than 0.3 mm and equal to or less than 6 mm, preferably equal to or greater than 0.5 mm and equal to or less than 4 mm. According to the above-described configuration, a size and a cross-sectional area of the inlet opening are appropriately set, and the fiber bundle can be appropriately converged while a suction flow rate in the fiber guide is sufficiently maintained.
The fiber guide may include an outlet opening formed on a rear end face, the outlet opening may include a linear base, and the base of the outlet opening may be provided to be inclined with respect to the straight line (D) of the inlet opening. In this case, the fiber bundle can be guided while being further converged.
When viewed in the axial direction of the fiber guide, an extension line of the base of the outlet opening and the reference straight line (D) of the inlet opening may intersect each other. In this case, further convergence of the fiber bundle described above is achieved in a more desirable state.
As still another aspect of the present invention, a fiber guide applied to an air-jet spinning device includes a front end face, an inlet opening formed on the front end face, and a chamfered section formed on

the front end face. At least a part of a boundary between the front end face and the chamfered section forms a chamfering straight line. In the fiber guide, when definition is made to each of: a line segment (E) defined as a width that is a longest part of the inlet opening; a straight line (A) passing through a center point (H) of the front end face and a midpoint of the line segment (E); a first inclined line (BL) obtained by inclining the straight line (A) by +45 degrees about the center point (H) of the front end face along the front end face; a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about the center point (H) of the front end face along the front end face; a first intersection (B) closer to the center point (H) among intersections of the front end face and the first inclined line (BL); a second intersection (C) closer to the center point (H) among intersections of the front end face and the second inclined line (CL) ; and a straight line (D) passing through the first intersection (B) and the second intersection (C), the fiber guide is arranged such that the chamfering straight line is inclined by equal to or greater than +10 degrees and equal to or less than +80 degrees, or equal to or less than -10 degrees and equal to or greater than -80

degrees with respect to the straight line (D) , when viewed in an axial direction of the fiber guide.
In this fiber guide, since the chamfering straight line is arranged to be inclined at the above-described inclination angle with respect to the straight line (D) at the inlet opening, the fiber bundle can be converged with the fiber bundle being bent in the fiber guide. As a result, uniformity of the yarn can be improved.
When viewed in the axial direction of the fiber guide, the chamfering straight line may be arranged so as to be inclined by equal to or greater than +15 degrees and equal to or less than +60 degree, or equal to or less than -15 degrees and equal to or greater than -60 degrees with respect to the straight line (D) . In this case, the improvement of the uniformity of the yarn can be more suitably achieved.
When viewed in the axial direction of the fiber guide, the chamfering straight line may be arranged so as to be inclined by equal to or greater than +20 degrees and equal to or less than +50 degrees, or equal to or less than -20 degrees and equal to or greater than -50 degrees with respect to the straight line (D) . In this case, the improvement of the uniformity of the yarn can be even more suitably achieved.

The chamfering straight line may be formed from a first peripheral edge to a second peripheral edge of the front end face. According to the configuration in which a straight part is long, visibility for a worker is enhanced. This may improve positioning accuracy of the fiber guide with respect to the nip line of the pair of front rollers.
The front end face may be formed with the chamfered section and a second chamfered section, and the chamfering straight line corresponding to at least a part of a boundary between the front end face and the chamfered section may be parallel to a second chamfering straight line corresponding to at least a part of a boundary between the front end face and the second chamfered section. In this case, the fiber guide can be arranged close to the pair of front rollers
The front end face may be formed with the chamfered section and a third chamfered section, and the chamfering straight line corresponding to at least a part of a boundary between the front end face and the chamfered section may be connected to a third chamfering straight line corresponding to at least a part of a boundary between the front end face and the third chamfered section, at a connection point located within a plane

excluding a peripheral edge of the front end face.
Either one of the chamfering straight line and the third chamfering straight line may be arranged parallel to the straight line (D). In this case, positioning of the fiber guide with respect to the nip line is easy.
At the inlet opening, the length of the line segment (E) may be equal to or greater than 2 mm and equal to or less than 14 mm, preferably equal to or greater than 4 mm and equal to or less than 10 mm, and the maximum height (Z) may be equal to or greater than 0.3 mm and equal to or less than 6 mm, preferably equal to or greater than 0.5 mm and equal to or less than 4 mm. According to the above-described configuration, a size and a cross-sectional area of the inlet opening are appropriately set, and the fiber bundle can be appropriately converged while a suction flow rate is sufficiently maintained.
A length (G) from the center point (H) of the front end face to the straight line (D) may be equal to or greater than 0.5 mm and equal to or less than 4.0 mm, and preferably equal to or greater than 0.5 mm and equal to or less than 2.5 mm. In this case, the fiber bundle can be spun after an appropriate tension is applied to the fiber bundle, and the quality of the yarn is

stabilized.
The fiber guide may include an outlet opening formed on a rear end face on an opposite side of the front end face, the outlet opening may include a linear base, and the base of the outlet opening may be provided to be inclined with respect to the straight line (D) of the inlet opening. In this case, the fiber bundle can be guided while being further converged.
An air-jet spinning device according to still another aspect of the present invention includes: a fiber guide having a front end face on which an inlet opening is formed; and a support block configured to support the fiber guide and detachably attached to a main body. The support block has a reference surface facing the main body. In the fiber guide, when definition is made to each of: a line segment (E) defined as a width that is a longest part of the inlet opening; a straight line (A) passing through a center point (H) of the front end face and a midpoint of the line segment (E); a first inclined line (BL) obtained by inclining the straight line (A) by +45 degrees about the center point (H) along the front end face; a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about the center point (H) along the front end face; a first

intersection (B) closer to the center point (H) among intersections of the inlet opening and the first inclined line (BL); a second intersection (C) closer to the center point (H) among intersections of the inlet opening and the second inclined line (CL); and a straight line (D) passing through the first intersection (B) and the second intersection (C), the fiber guide is arranged such that the straight line (D) is inclined by equal to or greater than +10 degrees and equal to or less than +80 degrees, or equal to or less than -10 degrees and equal to or greater than -80 degrees with respect to the reference surface of the support block when viewed in an axial direction of the fiber guide.
An air-jet spinning device according to still another aspect of the present invention includes: a fiber guide having a front end face on which an inlet opening is formed; a support block configured to support the fiber guide; and a turning shaft configured to turnably support the support block. In the fiber guide, when definition is made to each of: a line segment (E) defined as a width that is a longest part of the inlet opening; a straight line (A) passing through a center point (H) of the front end face and a midpoint of the line segment (E) ; a first inclined line (BL) obtained by inclining

the straight line (A) by +45 degrees about the center point (H) along the front end face; a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about the center point (H) along the front end face; a first intersection (B) closer to the center point (H) among intersections of the inlet opening and the first inclined line (BL); a second intersection (C) closer to the center point (H) among intersections of the inlet opening and the second inclined line (CL); and a straight line (D) passing through the first intersection (B) and the second intersection (C), the fiber guide is arranged such that the straight line (D) is inclined by equal to or greater than +10 degrees and equal to or less than +80 degrees, or equal to or less than -10 degrees and equal to or greater than -80 degrees with respect to a turning axis of the turning shaft when viewed in an axial direction of the fiber guide.
In the air-jet spinning device, the reference surface of the supporting block is often parallel or close to parallel to the nip line of the pair of front rollers. Even in a configuration in which the support block and the main body are integrally formed (that is, a configuration in which the support block is not able to be detached from the main body), the turning axis of

the support block is often parallel or close to parallel to the nip line of the pair of front rollers. In the above air-jet spinning device, the straight line (D) at the inlet opening of the fiber guide can be arranged to be inclined with respect to the nip line of the pair of front rollers. The fiber bundle can be converged with the fiber bundle being bent in the fiber guide. As a result, uniformity of the yarn can be improved.

WE CLAIM
1. A spinning machine (1) comprising:
a draft device (6) including a pair of front rollers (17) and configured to draft a fiber bundle (F); and
an air-jet spinning device (7) configured to produce a yarn (Y) by applying whirling airflow to the fiber bundle (F) drafted by the draft device (6), wherein
the air-jet spinning device (7) has a fiber guide (31) including: a front end face (31c) facing a nip line (L) of the pair of front rollers (17); and an inlet opening (31e) formed on the front end face (31c), and
in the fiber guide (31), when definition is made to each of:
a line segment (E) defined as a width that is a longest part of the inlet opening (31e);
a straight line (A) passing through a center point (H) of the front end face (31c) and a midpoint of the line segment (E) ;
a first inclined line (BL) obtained by inclining the straight line (A) by +45 degrees about the center point (H) along the front end face (31c);
a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about the center

point (H) along the front end face (31c);
a first intersection (B) closer to the center point (H) among intersections of the inlet opening (31e) and the first inclined line (BL);
a second intersection (C) closer to the center point (H) among intersections of the inlet opening (31e) and the second inclined line (CL); and
a straight line (D) passing through the first intersection (B) and the second intersection (C), and
the fiber guide (31) is arranged with the straight line (D) being inclined by equal to or greater than +10 degrees and equal to or less than +80 degrees, or equal to or less than -10 degrees and equal to or greater than -80 degrees with respect to the nip line (L), when viewed in an axial direction of the fiber guide (31).
2. A spinning machine (1) comprising:
a draft device (6) including a pair of front rollers (17) and configured to draft a fiber bundle (F); and
an air-jet spinning device (7) configured to produce a yarn (Y) by applying whirling airflow to the fiber bundle (F) drafted by the draft device (6), wherein
the air-jet spinning device (7) has a fiber guide

(31), and has a spinning chamber (32) internally formed and having a center line, the fiber guide (31) including: a front end face (31c) facing a nip line (L) of the pair of front rollers (17); and an inlet opening (31e) formed on the front end face (31c), and
in the fiber guide (31), when definition is made to each of:
a line segment (E) defined as a width that is a longest part of the inlet opening (31e);
a straight line (A) passing through an intersection (H) of the center line and the front end face (31c) and through a midpoint of the line segment (E);
a first inclined line (BL) obtained by inclining the straight line (A) by +45 degrees about the intersection (H) along the front end face (31c);
a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about the intersection (H) along the front end face (31c);
a first intersection (B) closer to the intersection (H) among intersections of the inlet opening (31e) and the first inclined line (BL);
a second intersection (C) closer to the intersection (H) among intersections of the inlet opening (31e) and the second inclined line (CL); and

a straight line (D) passing through the first intersection (B) and the second intersection (C), and
the fiber guide (31) is arranged with the straight line (D) being inclined by equal to or greater than +10 degrees and equal to or less than +80 degrees, or equal to or less than -10 degrees and equal to or greater than -80 degrees with respect to the nip line (L), when viewed in an axial direction of the fiber guide (31).
3. The spinning machine (1) as claimed in claim
1, wherein a length (G) from the center point (H) of the
front end face (31c) to the straight line (D) is equal
to or greater than 0.5 mm and equal to or less than 4.0
mm, and preferably equal to or greater than 0.5 mm and
equal to or less than 2.5 mm.
4. The spinning machine (1) as claimed in claim
2, wherein a length (G) from the intersection (H) of the
center line and the front end face (31c) to the straight
line (D) is equal to or greater than 0.5 mm and equal to
or less than 4.0 mm, and preferably equal to or greater
than 0.5 mm and equal to or less than 2.5 mm.
5. The spinning machine (1) as claimed in any one

of claims 1 to 4, wherein the fiber guide (31) is arranged with the straight line (D) being inclined by equal to or greater than +15 degrees and equal to or less than +60 degree, or equal to or less than -15 degrees and equal to or greater than -60 degrees with respect to the nip line (L) , when viewed in an axial direction of the fiber guide (31).
6. The spinning machine (1) as claimed in any one of claims 1 to 4, wherein the fiber guide (31) is arranged with the straight line (D) being inclined by equal to or greater than +20 degrees and equal to or less than +50 degrees, or equal to or less than -20 degrees and equal to or greater than -50 degrees with respect to the nip line (L) , when viewed in an axial direction of the fiber guide (31).
7. The spinning machine (1) as claimed in any one of claims 1 to 6, wherein the straight line (D) is inclined inversely with respect to a whirling direction of the whirling airflow.
8. The spinning machine (1) as claimed in any one of claims 1 to 7, wherein

at the inlet opening (31e) of the fiber guide (31),
a length of the line segment (E) is equal to or
greater than 2 mm and equal to or less than 14 mm,
preferably equal to or greater than 4 mm and equal to or
less than 10 mm, and
a maximum height (Z) is equal to or greater than 0.3 mm and equal to or less than 6 mm, and preferably equal to or greater than 0.5 mm and equal to or less than 4 mm.
9. The spinning machine (1) as claimed in any one
of claims 1 to 8, wherein
the fiber guide (31) includes an outlet opening (31f) formed on a rear end face (31d), and the outlet opening (31f) includes a linear base (31k), and
the base (31k) of the outlet opening (31f) is provided to be inclined with respect to the straight line (D) of the inlet opening (31e).
10. The spinning machine (1) as claimed in claim
9, wherein an imaginary extension line of the base (31k)
of the outlet opening (31f) and a reference straight
line (D) of the inlet opening (31e) intersect each other
when viewed in an axial direction of the fiber guide

(31) .
11. A fiber guide (31) applied to an air-jet spinning device (7), the fiber guide (31) comprising:
a front end face (31c);
an inlet opening (31e) formed on the front end face (31c); and
a chamfered section (61; 62: 63) formed on the front end face (31c), wherein
at least a part of a boundary between the front end face (31c) and the chamfered section (61; 62; 63) forms a chamfering straight line (J; Jl; J2), and
when definition is made to each of:
a line segment (E) defined as a width that is a longest part of the inlet opening (31e);
a straight line (A) passing through a center point (H) of the front end face (31c) and a midpoint of the line segment (E) ;
a first inclined line (BL) obtained by inclining the straight line (A) by +45 degrees about the center point (H) of the front end face (31c) along the front end face (31c);
a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about the center

point (H) of the front end face (31c) along the front end face (31c);
a first intersection (B) closer to the center point (H) among intersections of the front end face (31c) and the first inclined line (BL);
a second intersection (C) closer to the center point (H) among intersections of the front end face (31c) and the second inclined line (CL); and
a straight line (D) passing through the first intersection (B) and the second intersection (C), and
the chamfering straight line (J; Jl; J2) is arranged by being inclined by equal to or greater than + 10 degrees and equal to or less than +80 degrees, or equal to or less than -10 degrees and equal to or greater than -80 degrees with respect to the straight line (D), when viewed in an axial direction of the fiber guide (31) .
12. The fiber guide (31) as claimed in claim 11, wherein the chamfering straight line (J; Jl; J2) is arranged by being inclined by equal to or greater than + 15 degrees and equal to or less than +60 degree, or equal to or less than -15 degrees and equal to or greater than -60 degrees with respect to the straight line (D),

when viewed in an axial direction of the fiber guide (31) .
13. The fiber guide (31) as claimed in claim 11,
wherein the chamfering straight line (J; Jl; J2) is
arranged by being inclined by equal to or greater than
+ 20 degrees and equal to or less than +50 degrees, or
equal to or less than -20 degrees and equal to or greater
than -50 degrees with respect to the straight line (D),
when viewed in an axial direction of the fiber guide
(31) .
14. The fiber guide (31) as claimed in any one of claims 11 to 13, wherein the chamfering straight line (J; Jl) is formed from a first peripheral edge (71a; 72a) to a second peripheral edge (72a; 72b) of the front end face (31c).
15. The fiber guide (31) as claimed in any one of claims 11 to 14, wherein
the chamfered section (61) and a second chamfered section (62) are formed on the front end face (31c), and
the chamfering straight line (J) corresponding to at least a part of a boundary between the front end face

(31c) and the chamfered section(61) is parallel to a second chamfering straight line (Jl) corresponding to at least a part of a boundary between the front end face
(31c) and the second chamfered section (62).
16. The fiber guide (31) as claimed in any one of
claims 11 to 14, wherein
the chamfered section (62) and a third chamfered
section (63) are formed on the front end face (31c), and
the chamfering straight line (Jl) corresponding to
at least a part of a boundary between the front end face
(31c) and the chamfered section (62) is connected to a third chamfering straight line (J2) corresponding to at least a part of a boundary between the front end face
(31c) and the third chamfered section (63), at a connection point (PJ) located within a plane excluding a peripheral edge of the front end face (31c).
17. The fiber guide (31) as claimed in claim 16, wherein either one of the chamfering straight line (J, Jl) and the third chamfering straight line (J2) is arranged parallel to the straight line (D).
18. The fiber guide (31) as claimed in any one of

claims 11 to 17, wherein
at the inlet opening (31e),
a length of the line segment (E) is equal to or greater than 2 mm and equal to or less than 14 mm, preferably equal to or greater than 4 mm and equal to or less than 10 mm, and
a maximum height (Z) is equal to or greater than 0.3 mm and equal to or less than 6 mm, and preferably equal to or greater than 0.5 mm and equal to or less than 4 mm.
19. The fiber guide (31) as claimed in any one of claims 11 to 18, wherein a length (G) from the center point (H) of the front end face (31c) to the straight line (D) is equal to or greater than 0.5 mm and equal to or less than 4.0 mm, and preferably equal to or greater than 0.5 mm and equal to or less than 2.5 mm.
20. The fiber guide (31) as claimed in any one of claims 11 to 19, comprising
an outlet opening (31f) formed on a rear end face (31d) formed on an opposite side of the front end face (31c), the outlet opening (31f) including a linear base (31k), wherein

the base (31k) of the outlet opening (31f) is provided to be inclined with respect to the straight line (D) of the inlet opening (31e).
21. An air-jet spinning device (7) comprising:
a fiber guide (31) having a front end face (31c) on which an inlet opening (31e) is formed; and
a support block (37) configured to support the fiber guide (31) and detachably attached to a main body (40), wherein
the support block (37) has a reference surface (R) facing the main body (40), and
in the fiber guide (31), when definition is made to each of:
a line segment (E) defined as a width that is a longest part of the inlet opening (31e);
a straight line (A) passing through a center point (H) of the front end face (31c) and a midpoint of the line segment (E) ;
a first inclined line (BL) obtained by inclining the straight line (A) by +45 degrees about the center point (H) along the front end face (31c);
a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about the center

point (H) along the front end face (31c);
a first intersection (B) closer to the center point (H) among intersections of the inlet opening (31e) and the first inclined line (BL);
a second intersection (C) closer to the center point (H) among intersections of the inlet opening (31e) and the second inclined line (CL); and
a straight line (D) passing through the first intersection (B) and the second intersection (C), and
the fiber guide (31) is arranged with the straight line (D) being inclined by equal to or greater than +10 degrees and equal to or less than +80 degrees, or equal to or less than -10 degrees and equal to or greater than -80 degrees with respect to the reference surface (R) of the support block (37) when viewed in an axial direction of the fiber guide (31).
22. An air-jet spinning device (7) comprising:
a fiber guide (31) having a front end face (31c) on which an inlet opening (31e) is formed;
a support block (37) configured to support the fiber guide (31); and
a turning shaft (43) configured to turnably support the support block (37), wherein

in the fiber guide (31), when definition is made to each of:
a line segment (E) defined as a width that is a longest part of the inlet opening (31e);
a straight line (A) passing through a center point (H) of the front end face (31c) and a midpoint of the line segment (E) ;
a first inclined line (BL) obtained by inclining the straight line (A) by +45 degrees about the center point (H) along the front end face (31c);
a second inclined line (CL) obtained by inclining the straight line (A) by -45 degrees about the center point (H) along the front end face (31c);
a first intersection (B) closer to the center point (H) among intersections of the inlet opening (31e) and the first inclined line (BL);
a second intersection (C) closer to the center point (H) among intersections of the inlet opening (31e) and the second inclined line (CL); and
a straight line (D) passing through the first intersection (B) and the second intersection (C), and
the fiber guide (31) is arranged with the straight line (D) being inclined by equal to or greater than +10 degrees and equal to or less than +80 degrees, or equal

to or less than -10 degrees and equal to or greater than -80 degrees with respect to a turning axis of the turning shaft (43) when viewed in an axial direction of the fiber guide (31) .