SPINNING UNIT, PNEUMATIC SPINNING DEVICE, SPINNING
MACHINE, AND SPINNING METHOD
BACKGROUND OF THE INVENTION
5 1. Field of the Invention
The present invention relates mainly to a spinning
unit that performs spinning using air.
2. Description of the Related Art
10 The spinning unit that performs spinning using air
includes a draft device and a pneumatic spinning device.
The draft device drafts a fiber bundle with roller pairs.
The pneumatic spinning device includes a fiber guiding
member, a nozzle block, and a hollow guide shaft body.
15 The fiber bundle having been delivered from the draft
device is guided by the fiber guiding member. A spinning
nozzle is formed in the nozzle block. By ejection of
compressed air from the spinning nozzle, whirling
airflow is generated. This whirling airflow causes an
20 end of fibers of the fiber bundle to be reversed and
whirled around the hollow guide shaft body. This fiber
bundle advances downstream through a passage inside the
hollow guide shaft body. A spun yarn is formed by
applying twists to the fiber bundle when the fiber bundle
3
passes through the pneumatic spinning device. Japanese
Patent Laid-Open No. H6-41821 (Patent Document 1) and
Japanese Patent Laid-Open No. H6-41822 (Patent Document
2) disclose this type of spinning method.
5 Patent Documents 1 and 2 disclose a spindle (hollow
guide shaft body) and an air turbine. The spindle is
rotatably attached about a shaft center and is configured
to rotate during spinning. By being supplied with
compressed air, the air turbine rotationally drives the
10 spindle. Patent Document 1 describes that the spinning
nozzle is inclined 70° to 90° with respect to the yarn
advancing direction. Patent Document 2 describes that
the spinning nozzle is inclined 30° to 70° with respect
to the yarn advancing direction. Patent Documents 1 and
15 2 describe that a distance from a spindle inlet to a nip
point of the front roller (first distance) is 18.5 mm.
In Patent Document 1, since the inclination angle
of the spinning nozzle with respect to a spinning chamber
is small, the advancing component force is small and the
20 whirling component is large. Therefore, depending on
the raw material of the spun yarn, the end of the fibers
of the fiber bundle may not be sufficiently reversed.
In Patent Document 2, in order to spin wool fibers, the
length of the fiber bundle introduction hole is set to
4
be shorter than the distance between the downstream end
of the fiber bundle introduction hole and the spindle.
This is because wool fibers have a very long fiber length,
and in order to sufficiently reverse the end of the
5 fibers of the fiber bundle in the spinning chamber, the
distance between the downstream end of the fiber bundle
introduction hole and the spindle needs to be long in
Patent Document 2. However, in some cases, according to
the configuration of Patent Document 2, the end of the
10 fibers of the fiber bundle may be excessively reversed,
thereby failing to form a yarn having an acceptable
quality.
An optimum value of the first distance varies
depending on the type of the spinning nozzle, the raw
15 material of the spun yarn, the yarn count of the spun
yarn, and the like. When the first distance is short,
the end of the fibers of the fiber bundle tends not to
be sufficiently reversed.
20 BRIEF SUMMARY OF THE INVENTION
A main object of the present invention is to
provide a spinning unit that can appropriately reverse
and whirl the end of the fibers of the fiber bundle in
the pneumatic spinning device even when a front roller
5
and a hollow guide shaft body are arranged closely.
A spinning unit comprises a draft device
configured to include a front roller pair adapted to nip
and deliver a fiber bundle, the draft device being
5 adapted to draft the fiber bundle; and a pneumatic
spinning device having a fiber guiding member adapted to
guide the fiber bundle delivered by the draft device, a
hollow guide shaft body through which the fiber bundle
guided by the fiber guiding member passes, and a nozzle
10 block in which a spinning nozzle through which air to be
jetted into a spinning chamber passes is formed, the
spinning chamber being formed by including a space
between the fiber guiding member and the hollow guide
shaft body, wherein the hollow guide shaft body is
15 attached such that rotation about a shaft center is
restricted during spinning, a first distance, which is
a distance from a nip point of the front roller pair to
an upstream end of the hollow guide shaft body in a fiber
travelling direction, is equal to or greater than 13 mm
20 and less than 19 mm, a nozzle angle, which is an angle
formed by the shaft center of the hollow guide shaft
body and an extension line of the spinning nozzle, is
equal to or greater than 60° and equal to or less than
80°, and in a direction along the shaft center, a length
6
of the spinning chamber is equal to or less than a length
of the fiber guiding member.
A pneumatic spinning device comprises a fiber
guiding member adapted to guide a fiber bundle; a hollow
5 guide shaft body through which the fiber bundle guided
by the fiber guiding member passes inside; and a nozzle
block in which a spinning nozzle through which air to be
jetted into a spinning chamber passes is formed, the
spinning chamber being formed between the fiber guiding
10 member and the hollow guide shaft body, wherein the
hollow guide shaft body is attached such that rotation
about a shaft center is restricted during spinning, a
nozzle angle, which is an angle formed by the shaft
center of the hollow guide shaft body and an extension
15 line of the spinning nozzle, is equal to or greater than
60° and equal to or less than 80°, and a second distance,
which is a component in a direction parallel to the shaft
center of the hollow guide shaft body of a distance from
an upstream end of the fiber guiding member to a center
20 of an inlet of the spinning nozzle in a fiber travelling
direction, is equal to or greater than 3 mm and equal to
or less than 7 mm.
A spinning unit comprises the pneumatic spinning
device, wherein in a direction along the shaft center,
7
a length of the spinning chamber is equal to or less
than a length of the fiber guiding member.
A spinning machine comprises the spinning unit; a
first catching section adapted to catch a spun yarn on
5 the pneumatic spinning device side when the spun yarn is
brought into a disconnected state; a second catching
section adapted to catch a spun yarn on the package side
when the spun yarn is brought into the disconnected
state; and a yarn joining device adapted to join the
10 spun yarn caught by the first catching section and the
spun yarn caught by the second catching section.
A spinning method for forming a yarn using the
spinning unit, wherein spinning is performed using a
fiber bundle having an average fiber length of equal to
15 or less than 2 inches.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view illustrating an overall
configuration of a spinning machine including a spinning
20 unit according to an embodiment of the present invention;
FIG. 2 is a side view of the spinning unit;
FIG. 3 is a cross-sectional view illustrating a
configuration of a pneumatic spinning device;
FIG. 4 is a perspective view illustrating a
8
recessed portion formed in a nozzle block;
FIG. 5 is a cross-sectional view illustrating a
configuration of a pneumatic spinning device of a first
alternative embodiment;
5 FIG. 6 is a perspective view of a nozzle block, a
protection ring, and a third O-ring of the first
alternative embodiment;
FIG. 7 is a perspective view illustrating a
recessed portion and a reduced diameter portion formed
10 in a nozzle block of a second alternative embodiment;
FIG. 8 is a perspective view illustrating a reduced
diameter portion formed in a nozzle block of a third
alternative embodiment; and
FIG. 9 is a cross-sectional view illustrating a
15 configuration of a pneumatic spinning device of a fourth
alternative embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Next, a spinning machine 1 including a spinning
20 unit 2 according to an embodiment of the present
invention will be described with reference to the
drawings. The spinning machine 1 illustrated in FIG. 1
includes a multitude of the spinning units 2 arranged
side-by-side, a yarn joining cart 3, a motor box 4, and
9
a machine control device 90.
The machine control device 90, which is a device
that intensively manages each component of the spinning
machine 1, includes a monitor 91 and an input key 92.
5 The operator performs an appropriate operation using the
input key 92, whereby it is possible to perform setting
of a specific spinning unit 2 or all the spinning units
2 and to display the setting and the status of the
specific spinning unit 2 or all the spinning units 2 on
10 the monitor 91.
As illustrated in FIG. 2, each spinning unit 2
includes a draft device 7, a pneumatic spinning device
9, a yarn accumulating device 14, and a winding device
96 arranged in order from upstream to downstream. In
15 the present description, “upstream” and “downstream”
mean upstream and downstream in the travelling (passing)
direction of a fiber bundle 8 and a spun yarn 10 at the
time of spinning, or in a flow direction of compressed
air to be delivered. Each spinning unit 2 spins, with
20 the pneumatic spinning device 9, the fiber bundle 8 sent
from the draft device 7, thereby forming the spun yarn
10, and winds, with the winding device 96, the spun yarn
10, thereby forming a package 28. The spun yarn 10 is a
yarn thinner than a roving yarn. The roving yarn is
10
processed into the spun yarn 10 by being further drafted
(finely spun).
The draft device 7 is provided in a vicinity of an
upper end of a housing 5 of the spinning machine 1. The
5 draft device 7 includes four roller pairs, i.e., a back
roller pair 21, a third roller pair 22, a middle roller
pair 24 provided with an apron belt 23, and a front
roller pair 25 in order from upstream. The draft device
7 nips (sandwiches), with each roller pair, the fiber
10 bundle 8 (sliver) supplied from a sliver case not
illustrated via a sliver guide 20, and rotates the roller
pairs, thereby drafting the fiber bundle 8 (stretching
the fiber bundle 8) to a predetermined thickness. The
fiber bundle 8 drafted by the draft device 7 is supplied
15 to the pneumatic spinning device 9. Hereinafter, a
portion where the front roller pair 25 nips the fiber
bundle 8 is referred to as a nip point.
The pneumatic spinning device 9 uses whirling
airflow to apply twists to the fiber bundle 8 supplied
20 from the draft device 7, thereby forming the spun yarn
10. A specific configuration of the pneumatic spinning
device 9 will be described later.
The fiber bundle 8, which is the raw material of
the spun yarn 10 to be formed by the pneumatic spinning
11
device 9 in the present embodiment, preferably has an
average fiber length of equal to or less than 2 inches
(50.8 mm), for example.
The fiber bundle 8 preferably has a cotton blend
5 rate of equal to or greater than 50% and equal to or
less than 100%, for example.
A yarn quality measuring instrument 12 and a
spinning sensor 13 are provided downstream of the
pneumatic spinning device 9. The spun yarn 10 spun from
10 the pneumatic spinning device 9 passes through the yarn
quality measuring instrument 12 and the spinning sensor
13.
The yarn quality measuring instrument 12 monitors
the thickness of the traveling spun yarn 10 by an optical
15 sensor not illustrated. When detecting a yarn defect of
the spun yarn 10 (where abnormality is present in
thickness or the like of the spun yarn 10), the yarn
quality measuring instrument 12 transmits a yarn defect
detection signal to a unit controller not illustrated.
20 The yarn quality measuring instrument 12 is not limited
to an optical sensor, and may be configured to monitor
the thickness of the spun yarn 10 by using a capacitance
sensor, for example. The yarn quality measuring
instrument 12 may detect a foreign substance included in
12
the spun yarn 10 as a yarn defect.
The spinning sensor 13 is arranged immediately
downstream of the yarn quality measuring instrument 12.
The spinning sensor 13 can detect tension of the spun
5 yarn 10 between the pneumatic spinning device 9 and the
yarn accumulating device 14. The spinning sensor 13
transmits a detection signal of the detected tension to
the unit controller. The unit controller detects an
abnormal portion such as a weak yarn by monitoring the
10 tension detected by the spinning sensor 13. The spinning
unit 2 does not have to include the spinning sensor 13.
The yarn accumulating device 14 is provided
downstream of the yarn quality measuring instrument 12
and the spinning sensor 13. As illustrated in FIG. 2,
15 the yarn accumulating device 14 includes a yarn
accumulating roller 15 and a motor 16 that rotationally
drives the yarn accumulating roller 15.
The yarn accumulating roller 15 can wind a certain
amount of the spun yarn 10 around its outer peripheral
20 surface and temporarily accumulate the spun yarn 10. By
rotating the yarn accumulating roller 15 at a
predetermined rotation speed with the spun yarn 10 wound
around the outer peripheral surface of the yarn
accumulating roller 15, the spun yarn 10 can be pulled
13
out from the pneumatic spinning device 9 at a
predetermined speed and conveyed downstream.
Since the spun yarn 10 can be temporarily
accumulated on the outer peripheral surface of the yarn
5 accumulating roller 15, the yarn accumulating device 14
can function as a kind of buffer. Accordingly, it is
possible to eliminate a defect (such as slack of the
spun yarn 10) caused by disagreement between the spinning
speed in the pneumatic spinning device 9 and the winding
10 speed (speed of the spun yarn 10 to be wound on a package
28) for some reason.
The winding device 96 includes a cradle arm 97, a
winding drum 98, a traverse guide 99, and a winding drum
drive motor not illustrated. The cradle arm 97 can
15 rotatably support a bobbin for winding the spun yarn 10.
By a drive force of the winding drum drive motor being
transmitted, the winding drum 98 rotates in a state of
being in contact with the outer peripheral surface of
the bobbin or the package 28. The traverse guide 99 is
20 capable of guiding the spun yarn 10. While reciprocating
the traverse guide 99 by a driving means not illustrated,
the winding device 96 drives the winding drum 98 by the
winding drum drive motor. Accordingly, the winding
device 96 rotates the package 28 in contact with the
14
winding drum 98, and winds the spun yarn 10 around the
package 28 while traversing the spun yarn 10.
As illustrated in FIGS. 1 and 2, the yarn joining
cart 3 includes a yarn joining device 93, a suction pipe
5 (first catching section) 94, and a suction mouth (second
catching section) 95. When yarn breakage or yarn cutting
occurs in a certain spinning unit 2, the yarn joining
cart 3 travels to the relevant spinning unit 2 along a
rail not illustrated and stops. The suction pipe 94
10 rotates upwards about the shaft, catches the spun yarn
10 delivered from the pneumatic spinning device 9, and
rotates downwards about the shaft, thereby guiding the
spun yarn 10 to the yarn joining device 93. The suction
mouth 95 rotates downwards about the shaft, catches the
15 spun yarn 10 from the package 28, and rotates upwards
about the shaft, thereby guiding the spun yarn 10 to the
yarn joining device 93. The yarn joining device 93 joins
the guided spun yarns 10 together.
Next, the configuration of the pneumatic spinning
20 device 9 will be described in detail with reference to
FIGS. 3 and 4.
As illustrated in FIG. 3, the pneumatic spinning
device 9 includes a structure (single component;
structural object) 30, a needle-shaped member 51, a
15
structure support portion 53, a restriction plate
(restriction portion) 54, a cap portion 55, and a hollow
guide shaft body 58. In the following description, the
shaft center of the hollow guide shaft body 58 may be
5 simply referred to as the shaft center.
The structure 30 is a single member and configured
to include a fiber guiding member 31 and a nozzle block
32. The fiber guiding member 31 and the nozzle block 32
are configured as a single member. The fiber guiding
10 member 31 and the nozzle block 32 are integrally formed
using, for example, a mold, and there is no joint between
the fiber guiding member 31 and the nozzle block 32.
Alternatively, the fiber guiding member 31 and the nozzle
block 32 may be connected inseparably by welding or the
15 like so as to avoid a gap from being formed. However,
as illustrated in the fourth alternative embodiment
described later, the fiber guiding member 31 and the
nozzle block 32 may be separate members.
The fiber guiding member 31 guides, towards inside
20 the pneumatic spinning device 9, the fiber bundle 8
drafted by the draft device 7. The fiber guiding member
31 is hollow and is formed with a first passage 31a
through which the fiber bundle 8 passes.
The needle-shaped member 51 is arranged in the
16
first passage 31a. The fiber bundle 8 drafted by the
draft device 7 is introduced inside the fiber guiding
member 31 and guided along the first passage 31a. Then,
the fiber bundle 8 is guided to a spinning chamber 52
5 described later while being wound around the needleshaped member 51.
The nozzle block 32 is located on the downstream
side of the fiber guiding member 31. The nozzle block
32 is a substantially cylindrical member, and a plurality
10 of spinning nozzles 40, for example, four spinning
nozzles 40, are formed in the circumferential direction.
The spinning nozzle 40 is a through hole having a
circular cross section, for example, and is formed so as
to penetrate the nozzle block 32 in the radial direction.
15 The spinning nozzle 40 has an inlet 41 arranged on a
radially outer side of the nozzle block 32 and an
ejection port 42 arranged on a radially inner side of
the nozzle block 32. Compressed air flows in from the
inlet 41 and is ejected from the ejection port 42.
20 A space between the structure 30 and the hollow
guide shaft body 58 (in particular, a space including a
downstream surface of the fiber guiding member 31 and an
upstream surface of the hollow guide shaft body 58)
functions as the spinning chamber 52. The ejection port
17
42 of the spinning nozzle 40 is formed at a position
facing the spinning chamber 52. By ejecting compressed
air from the ejection port 42 of the spinning nozzle 40,
whirling airflow can be generated in the spinning chamber
5 52.
The fiber bundle 8 contains many fibers. The
downstream end of each fiber constituting the fiber
bundle 8 is twisted into other fibers while twists are
being applied. The upstream end of each fiber
10 constituting the fiber bundle 8 is a free end. The free
end of each fiber of the fiber bundle 8 introduced into
the pneumatic spinning device 9 flows downstream while
being whirled by the whirling airflow in the spinning
chamber 52. In this manner, the free end (upstream end)
15 of each fiber of the fiber bundle 8 flows downstream,
whereby the orientation of the upstream end is “reversed”
and faces downstream. By being affected by the whirling
airflow, the free end of the fibers of the fiber bundle
8 whirls around the surface (taper surface) of the hollow
20 guide shaft body 58. Accordingly, the reversed fibers
are sequentially wound around other fibers (core fibers).
As described above, the fibers are twisted and the spun
yarn 10 is formed.
Since the fiber bundle 8 is guided so as to be
18
wound around the needle-shaped member 51, even if twists
are applied to the fibers in the spinning chamber 52,
the twists are prevented from propagating upstream
relative to the fiber guiding member 31.
5 The structure support portion 53 is fixed to a
member for attaching the pneumatic spinning device 9.
The member is a frame of the spinning unit 2, for example.
The structure support portion 53 is arranged so as to
surround the structure 30 and the hollow guide shaft
10 body 58 in the circumferential direction. On the
upstream surface of the structure support portion 53,
the structure 30 (nozzle block 32) and the restriction
plate 54 are arranged. The structure support portion 53
supports the structure 30 and the restriction plate 54.
15 The restriction plate 54 restricts movement of the
structure 30 (nozzle block 32) towards the upstream side
in the fiber travelling direction (movement towards the
side closer to the draft device 7 along the shaft center).
The downstream end of the structure 30 is formed in a
20 radially expanding flange shape. The restriction plate
54 is arranged on the outer surface of this radially
expanding portion. A part of the structure 30 and a
part of the restriction plate 54 are in direct contact
with each other. A first O-ring 61 is sandwiched between
19
another part of the structure 30 and another part of the
restriction plate 54. By arranging the first O-ring 61,
compressed air can be prevented from leaking from between
the structure 30 and the restriction plate 54.
5 The restriction plate 54 is pressed against the
structure support portion 53 side by the cap portion 55
that is making contact with the restriction plate 54, or
is attached to the structure support portion 53 by a
fixture or the like. With this configuration, movement
10 of the structure 30 in the direction along the shaft
center is restricted.
The cap portion 55 covers the structure 30 with an
interval with respect to the structure 30. Accordingly,
a space covered with the structure 30, the restriction
15 plate 54, the cap portion 55, and the like is formed.
This space functions as an air path 56 through which
compressed air flowing towards the inlet 41 of the
spinning nozzle 40 passes.
A second O-ring 62 for preventing compressed air
20 from leaking from the air path 56 is arranged between
the restriction plate 54 and the cap portion 55. While
in the present embodiment, an O-ring groove is formed on
the restriction plate 54 side, the O-ring groove may be
formed on the cap portion 55 side.
20
A third O-ring 63 for preventing compressed air
from leaking from the air path 56 is arranged between
the structure 30 and the cap portion 55. While in the
present embodiment, an O-ring groove (O-ring attachment
5 portion) 33 is formed on the structure 30 side, the Oring groove may be formed on the cap portion 55 side.
The cap portion 55 presses the structure 30
radially inwards mainly, and does not press the structure
30 towards the structure support portion 53 side. That
10 is, the movement of the structure 30 in the direction
along the shaft center is restricted not by the cap
portion 55 but by the restriction plate 54.
A space that constitutes the downstream end of the
air path 56 and arranged around the inlet 41 of the
15 spinning nozzle 40 is referred to as an air storage space
57. In order to stably eject compressed air having a
sufficient flow rate from the ejection port 42, it is
necessary to form the air storage space 57 largely.
Specifically, the flow channel cross-sectional area of
20 the air storage space 57 is preferably twice or more the
flow channel cross-sectional area of the inlet 41. The
flow channel cross-sectional area is the area of a cross
section perpendicular to the flow channel of compressed
air. The direction of the flow channel of compressed
21
air can be regarded as the same as the axial direction
of the spinning nozzle 40.
The cap portion 55 of the present embodiment is
configured so that the inner diameter becomes smaller as
5 it approaches the upstream side in the fiber travelling
direction. Therefore, the air storage space 57 tends to
become small in the vicinity of the inlet 41. Therefore,
in the present embodiment, the flow channel crosssectional area of the air storage space 57 is increased
10 by recessing (making concave on) the outer surface of
the structure 30 (nozzle block 32).
Specifically, as illustrated in FIG. 4, a plurality
of first recessed portions 43 are formed on the outer
surface of the nozzle block 32. The first recessed
15 portion 43 is selectively formed at the position where
the inlet 41 is formed (in other words, the first
recessed portion 43 is formed only in a part in the
circumferential direction). The first recessed portion
43 is formed at a position farther from the inlet of the
20 fiber guiding member 31 than the O-ring groove 33 so as
not to be continuous with the O-ring groove 33. As long
as the flow channel cross-sectional area of the air
storage space 57 becomes large, the recessed portion may
be formed into any shape.
22
The hollow guide shaft body 58 is a hollow member,
and a second passage 58a is formed inside thereof. The
hollow guide shaft body 58 is arranged so as to face the
fiber guiding member 31 across the spinning chamber 52.
5 The hollow guide shaft body 58 is attached such that
rotation about the shaft center is restricted during
spinning. For example, the hollow guide shaft body 58
is attached to a member or the like that presses the
outer surface of the hollow guide shaft body 58 radially
10 inwards. Alternatively, the hollow guide shaft body 58
is configured so that when an attempt is made to rotate
the hollow guide shaft body 58, a part of the hollow
guide shaft body 58 (or a member that rotates integrally
with the hollow guide shaft body 58) interferes with
15 another member, and the hollow guide shaft body 58 cannot
rotate. The spun yarn 10 is guided to the downstream
side by the second passage 58a, and is delivered to the
outside of the pneumatic spinning device 9 from a yarn
outlet (not illustrated).
20 Next, a first distance L1, a second distance L2,
a nozzle angle θ, a length of the spinning chamber 52,
and a length of the fiber guiding member 31 will be
described with reference to FIG. 3.
As illustrated in FIG. 3, the distance from the
23
nip point of the front roller pair 25 to the upstream
end (more specifically, a point located on the upstream
end and the shaft center) of the hollow guide shaft body
58 is referred to as the first distance L1. The first
5 distance L1 is a linear distance, and is not a distance
along an actual travelling path of the fiber bundle 8.
Although the first distance L1 is the length of a line
segment in a three-dimensional space, it can also be
expressed as the length of a line segment in the view
10 (FIG. 3) seen in the axial direction of the front roller
pair 25. There is a tendency that the shorter the first
distance L1 is, the less the fibers to be reversed
becomes, and the less the winding fiber amount becomes.
Since the winding fiber amount may affect the quality of
15 the spun yarn 10 even if the winding fiber amount is
either too large or too small, an appropriate value is
set for the first distance L1 in accordance with the
shape of the nozzle block 32, the nature of the raw
material (fiber bundle 8), the yarn count of the spun
20 yarn 10 to be formed, and so forth. In the present
embodiment, in consideration of the situation that the
raw material is short fiber, the spun yarn 10 is formed
with a relatively short first distance L1, the distance
being equal to or greater than 13 mm and less than 19
24
mm. The first distance L1 may be preferably equal to or
greater than 13 mm and equal to or less than 16 mm. The
first distance L1 may be more preferably equal to or
greater than 15 mm and less than 19 mm.
5 As illustrated in FIG. 3, the component of the
distance from the upstream end of the fiber guiding
member 31 to the center of the inlet 41 of the spinning
nozzle 40 in the direction parallel to the shaft center
of the hollow guide shaft body 58 is referred to as the
10 second distance L2. The second distance L2 has a certain
degree of correlation with the first distance L1, and
there is a tendency that the shorter the first distance
L1 becomes, the shorter the second distance L2 becomes.
The second distance L2 is preferably equal to or greater
15 than 3 mm and equal to or less than 7 mm, for example.
The second distance L2 is more preferably equal to or
greater than 4 mm and equal to or less than 6 mm.
As described above, in the present embodiment, the
fiber guiding member 31 and the nozzle block 32 are
20 configured as a single member (structure 30). This
eliminates the need for an O-ring, a fixture, or the
like between the fiber guiding member 31 and the nozzle
block 32, thereby easily shortening the length in the
direction along the shaft center. Therefore, it is
25
possible to easily realize the configuration in which
the first distance L1 and the second distance L2
described above are short.
As illustrated in FIG. 3, the smaller one of the
5 angles formed by intersecting the shaft center of the
hollow guide shaft body 58 (first imaginary line 101)
and the extension line of the spinning nozzle 40 (second
imaginary line 102) (an angle formed by the shaft center
and the extension line of the spinning nozzle 40) is
10 referred to as the nozzle angle θ. Since the spinning
nozzle 40 of the present embodiment is linear, the axial
direction is the same in any cross section. Therefore,
the line in which this axial direction is extended
corresponds to the second imaginary line 102.
15 When the spinning nozzle 40 is not linear, in
consideration of the fact that the orientation of the
compressed air ejected from the ejection port 42 is
important, the line in which the axial direction of the
ejection port 42 is extended can be the second imaginary
20 line 102.
The larger the nozzle angle θ becomes, the larger
the component of the whirling airflow that whirls the
fibers of the fiber bundle 8 becomes, and the smaller
the component that sends the fiber bundle 8 to the
26
downstream side becomes. Since the component that
whirls the fibers of the fiber bundle 8 becomes large,
the free end of the fibers of the fiber bundle 8 are
easily swung around, and hence the winding property of
5 this free end can be facilitated. Accordingly, the
nozzle angle θ is preferably made large in a situation
where the first distance L1 is short, as in the present
embodiment. On the other hand, when the nozzle angle θ
is made too large, the fiber bundle 8 is not sufficiently
10 conveyed downstream. In consideration of the above, the
nozzle angle θ is preferably equal to or greater than
60° and equal to or less than 80°. Accordingly, the
free end of the fibers of the fiber bundle 8 can be sent
downstream while being sufficiently reversed and whirled.
15 While in the present embodiment, the structure 30
and the restriction plate 54 are separate members, they
may be configured as a single member. That is, the
pneumatic spinning device 9 may be configured so that
the structure 30 includes a restriction portion
20 extending radially outwards, and, by coming into contact
with the cap portion 55 (by being pressed to the
downstream side), the movement of the structure 30 is
restricted. Accordingly, the first O-ring 61 may be
omitted.
27
As described above, the spinning chamber 52 is a
space sandwiched by the downstream-side surface of the
fiber guiding member 31 and the upstream-side surface of
the hollow guide shaft body 58. The length of the
5 spinning chamber 52 is the length of the spinning chamber
52 in the direction along the shaft center. FIG. 3
illustrates the length of the spinning chamber 52 with
a reference symbol La given.
The length of the fiber guiding member 31 is a
10 length of the fiber guiding member 31 along the shaft
center, and more specifically, the length along the shaft
center from the upstream-side surface of the fiber
guiding member 31 to a surface of the fiber guiding
member 31 facing the spinning chamber 52. In other words,
15 the length of the fiber guiding member 31 is the length
of the first passage 31a. FIG. 3 illustrates the length
of the fiber guiding member 31 with a reference symbol
Lb given.
When the length La of the spinning chamber 52 is
20 too long, the end of the fibers of the fiber bundle 8
excessively reverses. In this regard, in the present
embodiment, the length La of the spinning chamber 52 is
equal to or greater than 0.3 mm and equal to or less
than the length of the fiber guiding member 31, and hence
28
the length La of the spinning chamber 52 is not too long
and is within an appropriate range. Accordingly, it is
possible to appropriately reverse the end of the fibers
of the fiber bundle 8 (prevent excessive reversal).
5 Next, a first alternative embodiment of the abovedescribed embodiment will be described with reference to
FIGS. 5 and 6. In the description of the first to third
alternative embodiments, members identical or similar to
those in the above-described embodiment are given
10 identical reference numerals in the drawings, and the
description thereof may be omitted.
The first alternative embodiment is different from
the above-described embodiment mainly in the shape of
the structure 30. On the outer surface of the structure
15 30 of the above-described embodiment, the O-ring groove
33 is formed so as not to be continuous with the first
recessed portion 43. On the outer surface of the
structure 30 of the first alternative embodiment, on the
other hand, an O-ring attachment step (O-ring attachment
20 portion) 36 is formed so as to be continuous with the
first recessed portion 43. The O-ring attachment step
36, which is a portion for attaching the third O-ring
63, is configured by reducing the diameter of a part of
the outer surface of the structure 30. That is, the O-
29
ring attachment step 36 has a step shape rather than a
groove shape, and hence it does not have a wall surface
closing the upstream side.
As illustrated in FIG. 3, the third O-ring 63
5 receives a force from the cap portion 55. Specifically,
the third O-ring 63 receives, from the cap portion 55,
not only a force directed radially inwards but also a
force directed towards downstream in the fiber
travelling direction (a force in an orientation parallel
10 to the shaft center of the hollow guide shaft body 58).
As described above, the O-ring attachment step 36 and
the first recessed portion 43 are formed so as to be
continuous. Therefore, there is a possibility that by
receiving the force directed towards downstream in the
15 fiber travelling direction from the cap portion 55, the
third O-ring 63 is damaged by being dug into the first
recessed portion 43.
In order to prevent damage, the third O-ring 63 is
attached to the O-ring attachment step 36 via a
20 protection ring 45. The protection ring 45 is a ringshaped member having an L-shaped cross section. The two
sides (two surfaces) constituting the L-shape are
arranged so as to make contact with the two sides (two
surfaces) constituting the O-ring attachment step 36,
30
respectively. That is, the protection ring 45 is
arranged so as to block the first recessed portion 43
continuous with the O-ring attachment step 36.
Accordingly, since the third O-ring 63 is prevented from
5 digging even when receiving a force directed towards
downstream from the cap portion 55, the third O-ring 63
is less likely damaged.
Next, the second alternative embodiment of the
above-described embodiment will be described with
10 reference to FIG. 7.
The second alternative embodiment is different
from the above-described embodiment mainly in the shape
of the recessed portion for forming the air storage space
57. In the above-described embodiment, in order to form
15 the air storage space 57, the plurality of first recessed
portions 43 are formed around the inlets 41. In the
second alternative embodiment, in addition to these
first recessed portions 43, a second recessed portion 46
is further formed. The second recessed portion 46 is
20 formed so as to be connected to the first recessed
portions 43 on the upstream side in the airflow direction.
The second recessed portion 46 is a reduced diameter
portion that is recessed in the radial direction over
the entire circumferential direction of the nozzle block
31
32 by reducing the diameter of the nozzle block 32. By
forming the second recessed portion 46, the flow channel
cross-sectional area can be sufficiently increased with
a simple configuration.
5 Next, the third alternative embodiment of the
above-described embodiment will be described with
reference to FIG. 8.
The third alternative embodiment is different from
the above-described embodiment mainly in the shape of
10 the recessed portion for forming the air storage space
57. In the third alternative embodiment, a third
recessed portion 47 is formed instead of the first
recessed portions 43 of the above-described embodiment.
Similarly to the second recessed portion 46, the third
15 recessed portion 47 is a reduced diameter portion that
is recessed in the radial direction over the entire
circumferential direction of the nozzle block 32 by
reducing the diameter of the nozzle block 32. The third
recessed portion 47 is formed so as to include a portion
20 where the inlet 41 is formed. Forming the third recessed
portion 47 instead of the first recessed portion 43
eliminates the need for process of selectively forming
the recessed portion in accordance with the position of
the inlet 41, and hence the flow channel cross-sectional
32
area can be made sufficiently large with a simple
configuration.
Next, the fourth alternative embodiment of the
above-described embodiment will be described with
5 reference to FIG. 9.
The fourth alternative embodiment is different
from the above-described embodiment in that the needleshaped member 51 is not included and that the fiber
guiding member 31 and the nozzle block 32 are separate
10 members. However, the pneumatic spinning device 9 may
be configured to have only one of these two differences.
As illustrated in FIG. 9, in the fiber guiding
member 31, a plane portion 151 is formed on a part of
the inner surface of the linearly extending first passage
15 31a. The plane portion 151 is arranged on the inner
surface of the first passage 31a, on the side closer to
the shaft center (first imaginary line 101) of the hollow
guide shaft body 58.
The plane portion 151 is arranged along the first
20 direction from an upstream end 31b to a downstream end
31c of the first passage 31a. The downstream end of the
plane portion 151 constitutes a part of the contour of
an opening formed in the spinning chamber 52 by the first
passage 31a.
33
The plane portion 151 has a flat shape without
twist. In other words, the angle of the linear portion
obtained by cutting the plane portion 151 with any plane
perpendicular to the first direction (direction in which
5 the first passage 31a extends) is constant from the
upstream end to the downstream end of the plane portion
151.
The plane portion 151 is arranged to deviate with
respect to the shaft center of the hollow guide shaft
10 body 58 in the direction orthogonal to the shaft center
of the hollow guide shaft body 58. Hereinafter, the
direction orthogonal to the shaft center of the hollow
guide shaft body 58 may be referred to as the second
direction.
15 Regarding the size of the above deviation, an
interval S1 in the second direction between the
downstream end of the plane portion 151 and the shaft
center of the hollow guide shaft body 58 (center of the
upstream end of the second passage 58a extending along
20 the shaft center of the hollow guide shaft body 58) is
equal to or greater than 0.8 mm and equal to or less
than 3.4 mm.
The interval S1 is the size of the distance in
which the plane portion 151 is arranged to deviate with
34
respect to the shaft center of the hollow guide shaft
body 58. If the interval S1 is too small, bending of
the travelling path of the fiber bundle 8 becomes loose,
and hence the force with which the fiber bundle 8 is
5 pressed against the plane portion 151 upstream of the
spinning chamber 52 becomes weak. As a result, the
restraint of the fiber bundle 8 becomes insufficient,
and the twists of the fiber bundle 8 in the spinning
chamber 52 propagates to the fiber bundle 8 located in
10 the first passage 31a. On the other hand, if the
interval S1 is too large, the inclination of the path of
the fiber bundle 8 in the spinning chamber 52 becomes
too much, and it is difficult to apply well the whirling
airflow to the fiber bundle 8. This indicates that by
15 setting the interval S1 within the above range, the
fibers in the spinning chamber 52 can be separated and
reversed well.
As described above, the spinning unit 2 of the
above-described embodiment includes the draft device 7
20 and the pneumatic spinning device 9. The draft device 7
is configured to include the front roller pair 25 that
nips and delivers the fiber bundle 8, and the draft
device 7 drafts the fiber bundle 8. The pneumatic
spinning device 9 has the fiber guiding member 31 that
35
guides the fiber bundle 8 delivered by the draft device
7, the hollow guide shaft body 58 through which the fiber
bundle 8 guided by the fiber guiding member 31 passes,
and the nozzle block 32 in which the spinning nozzle 40
5 through which air to be jetted into the spinning chamber
52 passes is formed, the spinning chamber 52 being formed
by including a space between the fiber guiding member 31
and the hollow guide shaft body 58. The hollow guide
shaft body 58 is attached such that rotation about the
10 shaft center is restricted. The first distance L1, which
is the distance from the nip point of the front roller
pair 25 to the upstream end of the hollow guide shaft
body 58 in the fiber travelling direction, is equal to
or greater than 13 mm and less than 19 mm. The nozzle
15 angle θ, which is the angle formed by the shaft center
of the hollow guide shaft body 58 and the extension line
of the spinning nozzle 40, is equal to or greater than
60° and equal to or less than 80°. In the direction
along the shaft center, the length La of the spinning
20 chamber 52 is equal to or less than the length of the
fiber guiding member 31.
Accordingly, even when the end of the fibers of
the fiber bundle 8 is difficult to be reversed in the
spinning chamber 52 due to the shortness of the first
36
distance L1 or the like, the nozzle angle θ is set in
the above range, and the length La of the spinning
chamber 52 is set in an appropriate range, whereby the
end of the fibers of the fiber bundle 8 can be
5 appropriately reversed and whirled. Since rotation
about the shaft center during spinning is restricted,
the hollow guide shaft body 58 has a simple structure.
In the spinning unit 2 of the above-described
embodiment, the second distance L2, which is a component
10 in the direction parallel to the shaft center of the
hollow guide shaft body 58 of the distance in the fiber
travelling direction from the upstream end of the fiber
guiding member 31 to the center of the inlet 41 of the
spinning nozzle 40, is equal to or greater than 3 mm and
15 equal to or less than 7 mm.
Accordingly, even when the second distance L2 is
so short that the fibers are difficult to be reversed in
the spinning chamber 52, the end of the fibers of the
fiber bundle 8 can be appropriately reversed and whirled.
20 In the spinning unit 2 of the above-described
embodiment, the fiber guiding member 31 and the nozzle
block 32 are configured as the single structure 30.
This eliminates the need for a sealing member that
is required when the fiber guiding member 31 and the
37
nozzle block 32 are configured as separate structures,
and hence the pneumatic spinning device 9 can be
downsized. In this case, it is possible to easily
realize the spinning unit 2 having the first distance L1
5 that is short.
In the spinning unit 2 of the above-described
embodiment or each alternative embodiment, the O-ring
attachment portion (O-ring groove 33, O-ring attachment
step 36) for attaching the third O-ring 63 is formed in
10 the structure 30.
This makes it possible to seal the gap between the
structure 30 and the member (cap portion 55) coming into
contact with the structure 30.
In the spinning unit 2 of the above-described
15 embodiment, the pneumatic spinning device 9 further
includes the cap portion 55 and the restriction plate
54. The cap portion 55 covers the structure 30 with an
interval with respect to the structure 30, whereby the
cap portion 55 forms the air path 56 through which the
20 air to be eject from the spinning nozzle 40 passes. The
restriction plate 54 is arranged around the structure 30
and comes into contact with the structure 30 and the cap
portion 55, thereby restricting movement of the
structure 30 to the upstream side in the fiber travelling
38
direction.
Accordingly, since the air path 56 can be formed
by the structure 30 and the cap portion 55, the
configuration of the pneumatic spinning device 9 can be
5 simplified. The pneumatic spinning device 9 includes
the restriction plate 54, thereby allowing the position
of the structure 30 to be stabilized.
Instead of the spinning unit 2 of the abovedescribed embodiment, the structure 30 may be configured
10 to further include the restriction portion whose
movement to the upstream side in the fiber travelling
direction is restricted by coming into contact with the
cap portion 55.
Accordingly, the restriction portion is included
15 in the structure 30, thereby eliminating the need for a
member (first O-ring 61) that seals between the
restriction portion and the structure 30.
In the spinning unit 2 of the above-described
embodiment, the recessed portion is formed on the outer
20 surface of the nozzle block 32 around the inlet 41 of
the spinning nozzle 40, whereby the air storage space 57
is formed.
Accordingly, air with a sufficient flow rate can
be ejected from the spinning nozzle 40.
39
In the spinning unit 2 of the above-mentioned
embodiment, the first recessed portion 43 is selectively
formed at a position including the inlet 41, thereby
forming the air storage space 57.
5 Accordingly, the air storage space 57 can be formed
while reducing a decrease in the strength of the nozzle
block 32.
In the spinning unit 2 of the second alternative
embodiment, on the outer surface of the nozzle block 32,
10 the second recessed portion 46 where the entirety in the
circumferential direction is recessed is formed upstream
of the selectively formed first recessed portion 43 in
the airflow direction so as to be continuous with the
first recessed portion 43.
15 Accordingly, the air storage space 57 can be formed
even larger.
In the spinning unit 2 of the third alternative
embodiment, the third recessed portion 47 where the
entirety in the circumferential direction including the
20 inlet 41 is formed, thereby forming the air storage space
57.
Accordingly, the process of forming the recessed
portion becomes easier, as compared with the
configuration in which a recess is selectively formed at
40
the location where the inlet 41 is formed. In addition,
the large air storage space 57 can be secured.
In the spinning unit 2 of the above-described
embodiment, the pneumatic spinning device 9 further
5 includes the needle-shaped member 51 arranged so that at
least a part thereof is positioned in the spinning
chamber 52 and the needle-shaped member 51 is arranged
along the shaft center of the hollow guide shaft body
58.
10 Accordingly, twists applied to the fiber bundle 8
are less likely to propagate to the upstream side.
In the spinning unit 2 of the fourth alternative
embodiment, the fiber guiding member 31 has the first
passage 31a through which the fiber bundle 8 passes.
15 The hollow guide shaft body 58 has the second passage
58a through which the fiber bundle 8 having passed
through the first passage 31a passes, and the hollow
guide shaft body 58 is provided so as to face the fiber
guiding member 31 across the spinning chamber 52. The
20 first passage 31a is provided so as to extend linearly.
The second passage 58a is provided so as to extend along
the shaft center of the hollow guide shaft body 58. The
downstream end where the first passage 31a opens to the
spinning chamber 52 and the upstream end where the second
41
passage 58a opens to the spinning chamber 52 are arranged
with an interval in the direction of the shaft center of
the hollow guide shaft body 58. The inner surface of
the first passage 31a has the flat plane portion 151 on
5 the side close to the shaft center of the hollow guide
shaft body 58. The angle of the linear portion obtained
by cutting the plane portion 151 with any plane
perpendicular to the first direction in which the first
passage 31a extends is constant from the upstream end
10 31b to the downstream end 31c of the first passage 31a.
The plane portion 151 is arranged to deviate with respect
to the shaft center of the hollow guide shaft body 58 in
the second direction perpendicular to the shaft center
of the hollow guide shaft body 58. The interval S1 in
15 the second direction between the downstream end of the
plane portion 151 and the shaft center of the hollow
guide shaft body 58 (center of the upstream end of the
second passage 58a) is equal to or greater than 0.8 mm
and equal to or less than 3.4 mm.
20 Accordingly, the fiber bundle 8 having been
supplied to the first passage 31a is restrained by coming
into contact with the flat plane portion 151 before
reaching the spinning chamber 52. Since the plane
portion 151 is arranged to deviate with respect to the
42
shaft center of the hollow guide shaft body 58, when the
fiber bundle 8 is appropriately bent between the first
passage 31a and the second passage 58a, the fiber bundle
8 is pressed well with respective to the plane portion
5 151. Therefore, even when twists are applied to the
fiber bundle 8 by the whirling airflow in the spinning
chamber 52, propagation of the twists to the upstream in
the travelling direction can be effectively reduced.
Thus, since the fibers are not wound around with each
10 other upstream relative to the spinning chamber 52, the
fibers can be separated and reversed well in the spinning
chamber 52. As a result, spinning can be stably
performed.
The spinning unit 2 of the above-described
15 embodiment further includes the winding device 96 that
winds the spun yarn 10 to form the package 28.
Accordingly, the spun yarn 10 formed by spinning
the fiber bundle 8 with the end of the fibers thereof
being sufficiently reversed is wound around the package
20 28, and hence the quality of the package 28 can be
improved.
The spinning machine 1 of the above-described
embodiment includes the suction pipe 94, the suction
mouth 95, and the yarn joining device 93. The suction
43
pipe 94 catches the spun yarn 10 on the pneumatic
spinning device 9 side when the spun yarn 10 is brought
into a disconnected state. The suction mouth 95 catches
the spun yarn 10 on the package 28 side when the spun
5 yarn 10 is brought into the disconnected state. The
yarn joining device 93 joins the spun yarn 10 caught by
the suction pipe 94 and the spun yarn 10 caught by the
suction mouth 95.
Accordingly, the spun yarns 10 formed by spinning
10 the fiber bundle 8 with the end of the fibers thereof
being sufficiently reversed are joined together, and
hence the yarn joining portion with a stable quality can
be formed and the quality of the package 28 can be
stabilized.
15 In the spinning method of the above-described
embodiment, spinning is performed using the fiber bundle
8 having an average fiber length of equal to or less
than 2 inches.
Accordingly, even when using a fiber bundle 8
20 composed of fibers having an average fiber length that
is not long, the spun yarn 10 having a stable quality
can be formed with a small fiber loss by forming the
spun yarn 10 using the spinning unit 2 of the abovedescribed embodiment.
44
In the spinning method of the above-described
embodiment, spinning is performed using the fiber bundle
8 having a cotton blend rate of equal to or greater than
50%.
5 Accordingly, even when using a fiber bundle 8
containing many cotton fibers having an average fiber
length that is particularly short, the spun yarn 10
having a stable quality can be formed with a small fiber
loss by forming the spun yarn 10 using the spinning unit
10 2 of the above-described embodiment.
While the preferred embodiment and alternative
embodiments of the present invention have been described
above, the above-described configuration can be modified
as below.
15 Any one of the first O-ring 61, the second O-ring
62, and the third O-ring 63 can be omitted, and instead,
the gap may be eliminated by press-fitting members
together.
The features of the above-described embodiment and
20 alternative embodiments can be combined as appropriate.
For example, the feature of the fourth alternative
embodiment that the needle-shaped member 51 is not
included may be applied to the embodiment and the first
to third alternative embodiments. The feature of the
45
fourth alternative embodiment that the fiber guiding
member 31 and the nozzle block 32 are separate members
may be applied to the embodiment and the first to third
alternative embodiments. The same is true for other
5 features.
At a position downstream of the pneumatic spinning
device 9, instead of or in addition to the yarn
accumulating device 14, a rotationally driven delivery
roller and a nip roller that is pressed against the
10 delivery roller may be provided, and the spun yarn 10
may be sandwiched between the delivery roller and the
nip roller to be send downstream. In this case, a slack
tube using suction airflow and/or a mechanical
compensator may be provided downstream of the delivery
15 roller and the nip roller.
The spinning machine 1 may not be provided with
the yarn joining cart 3, and each spinning unit 2 may
include the suction pipe 94, the suction mouth 95, and
the yarn joining device 93.
20 The spinning machine 1 may, without including the
yarn joining device 93, reversely convey the spun yarn
10 from the package 28 to the pneumatic spinning device
9, and restart the drafting operation by the draft device
7 and the spinning operation by the pneumatic spinning
46
device 9, thereby bringing the spun yarn 10 having been
disconnected into a continuous state (so-called piecing).
The draft device 7 and/or the winding device 96
may be driven independently for each spinning unit 2.
5 Although in the spinning unit 2, each device is
arranged so that the fiber passing direction is from the
upper side to the lower side, each device may be arranged
so that the fiber passing direction is from the lower
side to the upper side.
10 According to a first aspect of the present
invention, a spinning unit configured as follows is
provided. That is, this spinning unit includes a draft
device and a pneumatic spinning device. The draft device
is configured to include a front roller pair that nips
15 and delivers a fiber bundle, and the draft device drafts
the fiber bundle. The pneumatic spinning device has a
fiber guiding member that guides the fiber bundle
delivered by the draft device, a hollow guide shaft body
through which the fiber bundle guided by the fiber
20 guiding member passes inside, and a nozzle block in which
a spinning nozzle through which air to be jetted into a
spinning chamber passes is formed, the spinning chamber
being formed by including a space between the fiber
guiding member and the hollow guide shaft body. The
47
hollow guide shaft body is attached such that rotation
about a shaft center is restricted during spinning. A
first distance, which is a distance from a nip point of
the front roller pair to an upstream end of the hollow
5 guide shaft body in a fiber travelling direction, is
equal to or greater than 13 mm and less than 19 mm. A
nozzle angle, which is an angle formed by the shaft
center of the hollow guide shaft body and an extension
line of the spinning nozzle, is equal to or greater than
10 60° and equal to or less than 80°. In the direction
along the shaft center, a length of the spinning chamber
is equal to or less than a length of the fiber guiding
member.
Accordingly, even when the end of the fibers of
15 the fiber bundle is difficult to be reversed in the
spinning chamber due to the shortness of the first
distance or the like, the nozzle angle is set in the
above range, and the length of the spinning chamber is
set in an appropriate range, whereby the end of the
20 fibers of the fiber bundle can be appropriately reversed
and whirled.
In the spinning unit, a second distance, which is
a component in a direction parallel to the shaft center
of the hollow guide shaft body of the distance from the
48
upstream end of the fiber guiding member to a center of
an inlet of the spinning nozzle in the fiber travelling
direction, is preferably equal to or greater than 3 mm
and equal to or less than 7 mm.
5 Accordingly, even when the second distance is short
and the fibers are difficult to be reversed in the
spinning chamber, the end of the fibers of the fiber
bundle can be appropriately reversed and whirled.
According to a second aspect of the present
10 invention, a pneumatic spinning device configured as
follows is provided. That is, this pneumatic spinning
device includes the fiber guiding member, the hollow
guide shaft body, and the nozzle block. The fiber
guiding member guides the fiber bundle. The fiber bundle
15 guided by the fiber guiding member passes through the
hollow guide shaft body. In the nozzle block, the
spinning nozzle through which air to be jetted into the
spinning chamber passes is formed, the spinning chamber
being formed between the fiber guiding member and the
20 hollow guide shaft body. The hollow guide shaft body is
attached such that rotation about the shaft center is
restricted during spinning. A nozzle angle, which is an
angle formed by the shaft center of the hollow guide
shaft body and an extension line of the spinning nozzle,
49
is equal to or greater than 60° and equal to or less
than 80°. The second distance, which is a component in
the direction parallel to the shaft center of the hollow
guide shaft body of the distance from the upstream end
5 of the fiber guiding member to the center of the inlet
of the spinning nozzle in the fiber travelling direction,
is equal to or greater than 3 mm and equal to or less
than 7 mm.
Accordingly, even when the end of the fibers of
10 the fiber bundle is difficult to be reversed in the
spinning chamber due to the shortness of the first
distance because of the shortness of the second distance
or the like, the end of the fibers of the fiber bundle
can be appropriately reversed and whirled by setting the
15 nozzle angle in the above range.
According to a third aspect of the present
invention, a spinning unit configured as follows is
provided. That is, this spinning unit includes the
above-described pneumatic spinning device, and in the
20 direction along the shaft center, the length of the
spinning chamber is equal to or less than the length of
the fiber guiding member.
Accordingly, the end of the fibers of the fiber
bundle can be appropriately reversed and whirled in the
50
spinning chamber.
In the spinning unit, the fiber guiding member and
the nozzle block are preferably configured as a single
structure.
5 This eliminates the need for a sealing member that
is required when the fiber guiding member and the nozzle
block are configured as separate structures, and hence
the pneumatic spinning device can be downsized. In this
case, it is possible to easily realize the spinning unit
10 having the first distance that is short.
In the spinning unit, it is preferable that an Oring attachment portion for attaching an O-ring is formed
in the structure described above.
This makes it possible to seal a gap between the
15 structure and a member coming into contact with the
structure.
The spinning unit described above preferably has
the following configuration. That is, the pneumatic
spinning device further includes a cap portion and a
20 restriction portion. The cap portion covers the
structure with an interval with respect to the structure,
thereby forming an air path through which air to be
ejected from the spinning nozzle passes. The
restriction portion is arranged around the structure and
51
comes into contact with the structure and the cap portion,
thereby restricting movement of the structure to the
upstream side in the fiber travelling direction.
Accordingly, since an air path can be formed by
5 the structure and the cap portion, the configuration of
the pneumatic spinning device can be simplified. The
pneumatic spinning device includes the restriction
portion, thereby stabilizing the position of the
structure.
10 The spinning unit described above preferably has
the following configuration. That is, the pneumatic
spinning device further includes a cap portion that
covers the structure with an interval with respect to
the structure, whereby the cap portion forms an air path
15 through which air to be ejected from the spinning nozzle
passes. The structure is configured to further include
the restriction portion whose movement to the upstream
side in the fiber travelling direction is restricted by
coming into contact with the cap portion.
20 Accordingly, since an air path can be formed by
the structure and the cap portion, the configuration of
the pneumatic spinning device can be simplified. In
addition, the restriction portion is included in the
structure, thereby eliminating the need for a member
52
that seals between the restriction portion and the
structure.
In the spinning unit, it is preferable that a
recessed portion be formed on the outer surface of the
5 nozzle block around the inlet of the spinning nozzle,
thereby forming an air storage space.
Accordingly, air with a sufficient flow rate can
be ejected from the spinning nozzle.
In the spinning unit, it is preferable that the
10 recessed portion have a first recessed portion that forms
the air storage space, and the first recessed portion is
partially formed in a circumferential direction on the
outer surface of the nozzle block and formed at a
position including the inlet.
15 Accordingly, the air storage space can be formed
while reducing a decrease in the strength of the nozzle
block.
In the spinning unit, it is preferable that the
recessed portion have a second recessed portion formed
20 entirely in the circumferential direction on the outer
surface of the nozzle block, and the second recessed
portion is formed upstream of the first recessed portion
in an airflow direction so as to be continuous with the
first recessed portion.
53
Accordingly, the air storage space can be formed
even larger.
In the spinning unit, it is preferable that the
recessed portion have a third recessed portion that forms
5 the air storage space, and the third recessed portion is
formed by recessing the entirety in the circumferential
direction including the inlet.
Accordingly, the process of forming the recessed
portion becomes easier, as compared with the
10 configuration in which the recessed portion is partially
formed in the circumferential direction at a position
where the inlet is formed. In addition, a large air
storage space can be secured.
In the spinning unit, it is preferable that the
15 pneumatic spinning device further include a needleshaped member arranged so that at least a part thereof
is positioned in the spinning chamber and is along the
shaft center of the hollow guide shaft body.
Accordingly, twists applied to the fiber bundle
20 are less likely to propagate to the upstream side.
The spinning unit described above preferably has
the following configuration. That is, the fiber guiding
member has a first passage through which the fiber bundle
passes. The hollow guide shaft body has a second passage
54
through which the fiber bundle having passed through the
first passage passes, and is provided so as to face the
fiber guiding member across the spinning chamber. The
first passage is provided so as to extend linearly. The
5 second passage is provided so as to extend along the
shaft center of the hollow guide shaft body. A
downstream end where the first passage opens to the
spinning chamber and an upstream end where the second
passage opens to the spinning chamber are arranged with
10 an interval in the direction of the shaft center of the
hollow guide shaft body. An inner surface of the first
passage has a flat plane portion on the side close to
the shaft center of the hollow guide shaft body. An
angle of a linear portion obtained by cutting the plane
15 portion with any plane perpendicular to a first direction
in which the first passage extends is constant from the
upstream end to the downstream end of the first passage.
The plane portion is arranged to deviate with respect to
the shaft center of the hollow guide shaft body in a
20 second direction orthogonal to the shaft center of the
hollow guide shaft body. An interval in the second
direction between the downstream end of the plane portion
and the shaft center of the hollow guide shaft body is
equal to or greater than 0.8 mm and equal to or less
55
than 3.4 mm.
Accordingly, the fiber bundle having been supplied
to the first passage is restrained by coming into contact
with the flat plane portion before reaching the spinning
5 chamber. Since the plane portion is arranged to deviate
with respect to the shaft center of the hollow guide
shaft body, when the fiber bundle is appropriately bent
between the first passage and the second passage, the
fiber bundle is pressed well with respective to the plane
10 portion. Therefore, even when twists are applied to the
fiber bundle by the whirling airflow in the spinning
chamber, propagation of the twists to the upstream in
the travelling direction can be effectively reduced.
Thus, since the fibers are not wound around with each
15 other upstream relative to the spinning chamber,
separation and reversal of the fibers in the spinning
chamber can be performed well. Accordingly, spinning
can be stably performed.
It is preferable that the spinning unit further
20 include a winding device that winds the spun yarn to
form a package.
Accordingly, the spun yarn formed by spinning the
fiber bundle with the end of the fibers thereof being
sufficiently reversed is wound around the package, and
56
hence the quality of the package can be improved.
According to a fourth aspect of the present
invention, a spinning machine configured as follows is
provided. That is, this spinning machine includes a
5 first catching section, a second catching section, and
a yarn joining device. The first catching section
catches the spun yarn on the pneumatic spinning device
side when the spun yarn is brought into a disconnected
state. The second catching section catches the spun
10 yarn on the package side when the spun yarn is brought
into the disconnected state. The yarn joining device
joins the spun yarn caught by the first catching section
and the spun yarn caught by the second catching section.
Accordingly, the spun yarns formed by spinning the
15 fiber bundle with the end of the fibers thereof being
sufficiently reversed are joined together, and hence a
yarn joining portion with a stable quality can be formed
and the quality of the package can be stabilized.
According to a fifth aspect of the present
20 invention, a spinning method for forming a yarn using
the spinning unit is provided. In this spinning method,
spinning is performed using a fiber bundle having an
average fiber length of equal to or less than 2 inches.
Accordingly, even when using a fiber bundle
57
composed of fibers having an average fiber length that
is not long, a yarn having a stable quality can be formed
with a small fiber loss by forming the yarn using the
above spinning unit.
5 In the above spinning method, spinning is
preferably performed using a fiber bundle having a cotton
blend rate of equal to or greater than 50%.
Accordingly, even when using a fiber bundle
containing many cotton fibers having an average fiber
10 length that is particularly short, a yarn of stable
quality can be formed with a small fiber loss by forming
the yarn using the above spinning unit.

WE CLAIM
1. A spinning unit (2) comprising:
a draft device (7) configured to include a front
roller pair (25) adapted to nip and deliver a fiber
5 bundle (8), the draft device (7) being adapted to draft
the fiber bundle (8); and
a pneumatic spinning device (9) having a fiber
guiding member (31) adapted to guide the fiber bundle
(8) delivered by the draft device (7), a hollow guide
10 shaft body (58) through which the fiber bundle (8) guided
by the fiber guiding member (31) passes, and a nozzle
block (32) in which a spinning nozzle (40) through which
air to be jetted into a spinning chamber (52) passes is
formed, the spinning chamber (52) being formed by
15 including a space between the fiber guiding member (31)
and the hollow guide shaft body (58), wherein
the hollow guide shaft body (58) is attached such
that rotation about a shaft center (101) is restricted
during spinning,
20 a first distance (L1), which is a distance from a
nip point of the front roller pair (25) to an upstream
end of the hollow guide shaft body (58) in a fiber
travelling direction, is equal to or greater than 13 mm
and less than 19 mm,
59
a nozzle angle (θ), which is an angle formed by
the shaft center (101) of the hollow guide shaft body
(58) and an extension line (102) of the spinning nozzle
(40), is equal to or greater than 60° and equal to or
5 less than 80°, and
in a direction along the shaft center (101), a
length (La) of the spinning chamber (52) is equal to or
less than a length of the fiber guiding member (31).
10 2. The spinning unit (2) as claimed in claim 1,
wherein a second distance (L2), which is a component in
a direction parallel to the shaft center (101) of the
hollow guide shaft body (58) of a distance from an
upstream end (31b) of the fiber guiding member (31) to
15 a center of an inlet (41) of the spinning nozzle (40) in
a fiber travelling direction, is equal to or greater
than 3 mm and equal to or less than 7 mm.
3. A pneumatic spinning device (9) comprising:
20 a fiber guiding member (31) adapted to guide a
fiber bundle (8);
a hollow guide shaft body (58) through which the
fiber bundle (8) guided by the fiber guiding member (31)
passes inside; and
60
a nozzle block (32) in which a spinning nozzle (40)
through which air to be jetted into a spinning chamber
(52) passes is formed, the spinning chamber (52) being
formed between the fiber guiding member (31) and the
5 hollow guide shaft body (58), wherein
the hollow guide shaft body (58) is attached such
that rotation about a shaft center (101) is restricted
during spinning,
a nozzle angle (θ), which is an angle formed by
10 the shaft center (101) of the hollow guide shaft body
(58) and an extension line of the spinning nozzle (40),
is equal to or greater than 60° and equal to or less
than 80°, and
a second distance (L2), which is a component in a
15 direction parallel to the shaft center (101) of the
hollow guide shaft body (58) of a distance from an
upstream end (31b) of the fiber guiding member (31) to
a center of an inlet (41) of the spinning nozzle (40) in
a fiber travelling direction, is equal to or greater
20 than 3 mm and equal to or less than 7 mm.
4. A spinning unit (2) comprising:
the pneumatic spinning device (9) as claimed in
claim 3,
61
wherein in a direction along the shaft center (101),
a length (La) of the spinning chamber (52) is equal to
or less than a length of the fiber guiding member (31).
5 5. The spinning unit (2) as claimed in claim 1,
2, or 4, wherein the fiber guiding member (31) and the
nozzle block (32) are configured as a single structure
(30).
6. The spinning unit (2) as claimed in claim 5,
10 wherein an O-ring attachment portion (33; 36) for
attaching an O-ring (61; 62; 63) is formed in the
structure (30).
7. The spinning unit (2) as claimed in claim 5 or
6, wherein the pneumatic spinning device (9) includes
15 a cap portion (55) adapted to cover the structure
(30) with an interval with respect to the structure (30),
thereby forming an air path (56) through which air to be
ejected from the spinning nozzle (40) passes, and
a restriction portion that is arranged around the
20 structure (30 and comes into contact with the structure
(30) and the cap portion (55), thereby restricting
movement of the structure (30) to an upstream side in a
fiber travelling direction.
62
8. The spinning unit (2) as claimed in claim 5 or
6, wherein the pneumatic spinning device (9) includes a
cap portion (55) adapted to cover the structure (30)
with an interval with respect to the structure (30),
5 thereby forming an air path (56) through which air to be
ejected from the spinning nozzle (40) passes, and
the structure (30) is configured to include a
restriction portion whose movement to an upstream side
in a fiber travelling direction is restricted by coming
10 into contact with the cap portion (55).
9. The spinning unit (2) as claimed in claim 1,
2, 4, 5, 6, 7, or 8, wherein a recessed portion (43; 46;
47) is formed on an outer surface of the nozzle block
15 (32) around the inlet (41) of the spinning nozzle (40),
thereby forming an air storage space (57).
10. The spinning unit (2) as claimed in claim 9,
wherein
20 the recessed portion has a first recessed portion
(43) that forms the air storage space (57), and
the first recessed portion (43) is partially formed
in a circumferential direction on the outer surface of
the nozzle block (32) and formed at a position including
63
the inlet (41).
11. The spinning unit (2) as claimed in claim 10,
wherein the recessed portion has a second recessed
5 portion (46) formed entirely in the circumferential
direction on an outer surface of the nozzle block (32),
and
the second recessed portion (46) is formed
upstream of the first recessed portion (43) in an airflow
10 direction so as to be continuous with the first recessed
portion (43).
12. The spinning unit (2) as claimed in claim 9,
wherein the recessed portion has a third recessed portion
15 (47) that forms the air storage space (57), and
the third recessed portion (47) is formed by
recessing entirety in a circumferential direction
including the inlet (41).
20 13. The spinning unit (2) as claimed in claim 1,
2, 4, 5, 6, 7, 8, 9, 10, 11, or 12, wherein the pneumatic
spinning device (9) includes a needle-shaped member (51)
arranged so that at least a part of the needle-shaped
member (51) is positioned in the spinning chamber (52)
64
and is arranged along the shaft center (101) of the
hollow guide shaft body (58).
14. The spinning unit (2) as claimed in claim 1,
5 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13, wherein
the fiber guiding member (31) has a first passage
(31a) through which the fiber bundle (8) passes,
the hollow guide shaft body (58) has a second
passage (58a) through which the fiber bundle (8) having
10 passed through the first passage (31a) passes, and is
provided so as to face the fiber guiding member (31)
across the spinning chamber (52),
the first passage (31a) is provided so as to extend
linearly,
15 the second passage (58a) is provided so as to
extend along the shaft center (101) of the hollow guide
shaft body (58),
a downstream end (31c) where the first passage
(31a) opens to the spinning chamber (52) and an upstream
20 end where the second passage (58a) opens to the spinning
chamber (52) are arranged with an interval in a direction
of the shaft center (101) of the hollow guide shaft body
(58),
an inner surface of the first passage (31a) has a
65
flat plane portion (151) on a side close to the shaft
center (101) of the hollow guide shaft body (58),
an angle of a linear portion obtained by cutting
the plane portion (151) with any plane perpendicular to
5 a first direction in which the first passage (31a)
extends is constant from an upstream end (31b) to a
downstream end (31c) of the first passage (31a),
the plane portion (151) is arranged to deviate with
respect to the shaft center (101) of the hollow guide
10 shaft body (58) in a second direction orthogonal to the
shaft center (101) of the hollow guide shaft body (58),
and
an interval (s1) in the second direction between a
downstream end of the plane portion (151) and the shaft
15 center (101) of the hollow guide shaft body (58) is equal
to or greater than 0.8 mm and equal to or less than 3.4
mm.
15. The spinning unit (2) as claimed in claim 1,
2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14, wherein the
20 spinning unit (2) includes a winding device (96) adapted
to wind a spun yarn (10) to form a package (28).
16. A spinning machine (1) comprising:
the spinning unit (2) as claimed in claim 15;
66
a first catching section (94) adapted to catch a
spun yarn (10) on the pneumatic spinning device (9) side
when the spun yarn (10) is brought into a disconnected
state;
5 a second catching section (95) adapted to catch a
spun yarn (10) on the package (28) side when the spun
yarn (10) is brought into the disconnected state; and
a yarn joining device (93) adapted to join the spun
yarn (10) caught by the first catching section (94) and
10 the spun yarn (10) caught by the second catching section
(95).
17. A spinning method for forming a yarn (10)
using the spinning unit (2) as claimed in claim 1, 2, 4,
15 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15, wherein spinning
is performed using a fiber bundle (8) having an average
fiber length of equal to or less than 2 inches.
18. The spinning method as claimed in claim 17,
20 wherein spinning is performed using a fiber bundle (8)
having a cotton blend rate of equal to or greater than
50%.