TECHNICAL FIELD
[0001] The present invention relates to a technique of a yarn length measurement device
capable of measuring a yarn length of a knitting yarn fed out from a buffer device,
and the buffer device for the knitting yarn.
BACKGROUND ART
[0002] Conventionally, a technique of measuring a yarn length of a knitting yarn fed out
from a buffer device and fed to a knitting machine is known. For example, Patent Literature
1 discloses such a technique.
[0003] Patent Literature 1 discloses a technique capable of measuring a pull-out amount
when the yarn accumulated on a rotary drum is pulled out.
[0004] In the technique described in Patent Literature 1, optical sensors are disposed at
four locations at intervals of 90 degrees in a circumferential direction around the
rotary drum, and each of the optical sensors detects blocking of light by the yarn
to be pulled out, thereby measuring the pull-out amount of the yarn.
CITATION LIST
PATENT LITERATURE
SUMMARY OF INVENTION
TECHNICAL PROBLEM
[0006] However, in the technique described in Patent Literature 1, even if the optical sensors
are disposed at four locations, the yarns passing between the optical sensors cannot
be detected, and thus there is room for improvement in the accuracy of the yarn length
measurement.
[0007] The present invention has been made in view of the above circumstances, and an object
thereof is to provide a yarn length measurement device and a buffer device for a knitting
yarn capable of realizing highly accurate yarn length measurement.
SOLUTION TO PROBLEM
[0008] The problem to be solved by the present invention is as described above, and means
for solving the problem will be described below.
[0009] In other words, a yarn length measurement device according to the present invention
includes: a rotating member rotatably provided with respect to a predetermined mounting
member; an introduction part that is provided at a position deviated from a rotation
axis of the rotating member and introduces a knitting yarn unwound from an upstream
side in a yarn feeding direction to a downstream side in the yarn feeding direction;
a lead-out part that leads out the knitting yarn introduced from the introduction
part to a yarn feeding path on the downstream side in the yarn feeding direction;
and a rotation amount detection part that detects a rotation amount of the rotating
member.
[0010] With such a configuration, highly accurate yarn length measurement can be realized.
[0011] Furthermore, the lead-out part may be provided on a rotation axis of the rotating
member.
[0012] With such configuration, a load on the knitting yarn can be reduced.
[0013] Furthermore, the introduction part may be formed at a position where a shortest distance
to the rotation axis is shorter than 20 mm.
[0014] With such a configuration, the yarn length measurement with higher accuracy can be
realized.
[0015] Furthermore, the rotation amount detection part may include a part to be detected
that rotates integrally with the rotating member, and may detect the rotation amount
by detecting a change in a surface of the part to be detected accompanying a rotation
of the part to be detected.
[0016] With such a configuration, the yarn length measurement with higher accuracy can be
realized.
[0017] Furthermore, a buffer device according to the present invention includes: the yarn
length measurement device according to the present invention; and a bobbin wound and
stored with the knitting yarn, the bobbin being disposed on the upstream side in the
yarn feeding direction of the yarn length measurement device.
[0018] With such a configuration, highly accurate yarn length measurement can be realized.
ADVANTAGEOUS EFFECTS OF INVENTION
[0019] As an effect of the present invention, an effect of realizing highly accurate yarn
length measurement is obtained.
BRIEF DESCRIPTION OF DRAWINGS
[0020]
Fig. 1 is a front view illustrating an overall configuration of a flat knitting machine
including a yarn length measurement device and a buffer device according to a first
embodiment of the present invention.
Fig. 2 is a block diagram illustrating a configuration related to control of the flat
knitting machine.
Fig. 3 is a front view illustrating a yarn feeding device including a yarn length
measurement device and a buffer device.
Fig. 4 is a front view illustrating a yarn length measurement device.
Fig. 5 is a front view illustrating a rotating member.
Fig. 6(a) is a front view illustrating a state of measuring a yarn length of a knitting
yarn by a yarn length measurement device. Fig. 6(b) is a cross-sectional view taken
along line X-X in Fig. 6(a).
Fig. 7(a) is a front view illustrating a rotating member according to a second embodiment.
Fig. 7(b) is a perspective view illustrating a rotating member according to a third
embodiment. Fig. 7(c) is a perspective view illustrating a rotating member according
to a fourth embodiment.
Fig. 8(a) is a front view illustrating a rotating member according to a fifth embodiment.
Fig. 8(b) is a front view illustrating a rotating member according to a sixth embodiment.
DESCRIPTION OF EMBODIMENTS
[0021] In the following description, directions indicated by arrows U, D, F, B, L, and R
in the drawings are defined as an upward direction, a downward direction, a forward
direction, a backward direction, a left direction, and a right direction, respectively.
Furthermore, in each drawing, for convenience of description, illustration of some
members may be appropriately omitted.
[0022] First, an overall configuration of a flat knitting machine 1 including a yarn feeding
device 100 according to a first embodiment of the present invention will be described.
[0023] As illustrated in Figs. 1 and 2, the flat knitting machine 1 mainly includes needle
beds 10, a carriage 20, a yarn path rail 30, a servomotor 40, a yarn upright base
50, a control unit 60, and the yarn feeding device 100.
[0024] The needle beds 10 illustrated in Fig. 1 are disposed so as to face each other in
a front-back direction with a needle bed gap (not illustrated) interposed therebetween.
The front and back needle beds 10 are disposed, for example, in an inverted V shape
in a side view so as to be inclined upward toward front and back central sides (sides
facing each other). Each of the needle beds 10 is provided with a large number of
knitting needles 11 arranged along a longitudinal direction (left-right direction)
of the needle bed 10. The front and back needle beds 10 can be relatively moved to
the left and right when carrying out the transfer (stitch transfer) of stitches with
respect to each other.
[0025] A pair of the front and back carriages 20 is disposed to face the front and back
needle beds 10 from above. The front and back carriages 20 are connected by a bridge
20a disposed to straddle a plurality of the yarn path rails 30. Each of the carriages
20 can reciprocate along the longitudinal direction of each of the needle beds 10
by the servomotor 40 (See Fig. 2). The carriage 20 is provided with a needle selecting
mechanism (not illustrated) and a cam mechanism 21 (See Fig. 2) for selectively operating
the knitting needles 11 of the needle bed 10.
[0026] The plurality of yarn path rails 30 illustrated in Fig. 1 are disposed above the
needle bed gap so as to extend along the longitudinal direction of the needle bed
10. A yarn carrier 31 that feeds a knitting yarn Y is supported on the yarn path rails
30 so as to be movable.
[0027] The yarn upright base 50 illustrated in Fig. 1 is provided with a yarn cone 51 around
which the knitting yarn Y is wound. The knitting yarn Y from the yarn cone 51 is fed
to the yarn carrier 31 through a yarn feeding path A. Here, the yarn feeding path
A is a path through which the knitting yarn Y from the yarn cone 51 to the yarn carrier
31 is fed. Furthermore, a top spring 52 is disposed above the yarn cone 51. The top
spring 52 applies tension to the knitting yarn Y pulled out from the yarn cone 51
and fed to a downstream side in a yarn feeding direction (a yarn carrier 31 side).
The top spring 52 is located on the yarn feeding path A.
[0028] The control unit 60 illustrated in Fig. 2 is for controlling an operation of the
flat knitting machine 1. The control unit 60 includes an arithmetic processing unit
such as a CPU, a storage unit such as a RAM and a ROM, and the like. The storage unit
of the control unit 60 stores various information, programs, and the like used for
controlling the flat knitting machine 1. The control unit 60 is disposed at an appropriate
location (for example, in a main body of the flat knitting machine 1 (under the needle
bed 10 on the back side)) of the flat knitting machine 1.
[0029] The control unit 60 is connected to the servomotor 40 and can control an operation
of the servomotor 40. The control unit 60 can arbitrarily move the carriage 20 by
controlling the operation of the servomotor 40. The control unit 60 can detect a position
of the carriage 20 based on the number of rotations of the servomotor 40. The control
unit 60 is connected to the carriage 20 (more specifically, the cam mechanism 21),
and can control the operation of the carriage 20.
[0030] The control unit 60 controls each part of the flat knitting machine 1 based on a
knitting program and the like created in advance. Specifically, the control unit 60
can reciprocate the carriage 20 along the longitudinal direction of the needle bed
10 by controlling the operation of the servomotor 40. In this case, the knitting operation
such as knit, tuck, miss, and the like, and the transfer of the stitches between the
front and back needle beds 10 can be carried out by advancing and retreating the knitting
needles 11 with respect to the needle bed gap by the cam mechanism 21 and the like
mounted on the carriage 20. A knitted fabric K is knitted by repeating such reciprocating
movement of the carriage 20.
[0031] Next, a configuration of the yarn feeding device 100 will be described with reference
to Figs. 1 to 6. The yarn feeding device 100 stores the knitting yarn Y from the yarn
cone 51, and feeds the stored knitting yarn Y to the yarn carrier 31 with a substantially
constant tension. As illustrated in Fig. 1, the yarn feeding device 100 is disposed
on a side (left side in the drawing example) of the flat knitting machine 1. The yarn
feeding device 100 is located in the yarn feeding path A. Note that, in the drawing
example, one yarn feeding device 100 is illustrated, but a plurality of the yarn feeding
devices 100 (for example, the number corresponding to the number of yarn carriers
31) can be disposed as necessary. The yarn feeding device 100 mainly includes a support
part 110, a buffer device 120, a resistance applying part 130, a yarn length measurement
device 200, and a control unit 300.
[0032] The support part 110 illustrated in Fig. 3 supports the buffer device 120, the yarn
length measurement device 200, and the like to be described later. The support part
110 is formed by combining a plurality of plate-shaped members, for example. The support
part 110 is installed in an appropriate installation target. The support part 110
includes an upper guide part 111 and a lower guide part 112.
[0033] The upper guide part 111 is a part into which the knitting yarn Y from the top spring
52 is introduced. The upper guide part 111 has a hole that penetrates in a vertical
direction and through which the knitting yarn Y passes. The upper guide part 111 is
supported through an appropriate arm protruding rightward from a right surface of
the support part 110.
[0034] The lower guide part 112 is a part from which the knitting yarn Y from the buffer
device 120 to be described later is led out. The lower guide part 112 has a hole that
penetrates in the vertical direction and through which the knitting yarn Y passes.
The lower guide part 112 is supported below the upper guide part 111 through an appropriate
arm protruding rightward from the right surface of the support part 110.
[0035] The buffer device 120 illustrated in Fig. 3 pulls out the knitting yarn Y from the
yarn cone 51 and stores the knitting yarn Y. The knitting yarn Y stored in the buffer
device 120 is pulled out (fed out) to a downstream side in the yarn feeding direction
as necessary. The buffer device 120 is provided on the support part 110 so as to be
located between the upper guide part 111 and the lower guide part 112. The buffer
device 120 includes a housing 121, a drive unit 122, a winding part 123, and a bobbin
124.
[0036] The housing 121 accommodates the drive unit 122 to be described later. The housing
121 is fixed to the right surface of the support part 110.
[0037] The drive unit 122 illustrated in Figs. 2 and 3 drives the winding part 123 to be
described later. The drive unit 122 is provided inside the housing 121. The drive
unit 122 includes an appropriate drive source (for example, a motor or the like).
[0038] The winding part 123 illustrated in Fig. 3 winds the knitting yarn Y from the upper
guide part 111 around the bobbin 124 to be described later. The winding part 123 is
located below the housing 121 and is rotatably provided with respect to the housing
121. The winding part 123 rotates about a rotation axis oriented in the vertical direction
by a driving force of the drive unit 122. The winding part 123 rotates clockwise in
plan view.
[0039] The bobbin 124 illustrated in Figs. 3 and 4 can store the knitting yarn Y. The bobbin
124 is formed in a substantially cylindrical shape with an axial direction oriented
in the vertical direction. The bobbin 124 is provided in the housing 121 so as to
be located below the winding part 123. The bobbin 124 stores the knitting yarn Y by
winding the knitting yarn Y around an outer peripheral surface. The knitting yarn
Y is wound around the bobbin 124 by the winding part 123 in a constant winding manner
(so that the yarn length per turn becomes substantially the same length).
[0040] The knitting yarn Y stored in the bobbin 124 is pulled out (unwound) with the knitting
operation of the flat knitting machine 1 (carriage 20, yarn carrier 31, and the like),
and fed toward the downstream side in the yarn feeding direction. A position of the
knitting yarn Y unwound from the bobbin 124 changes so as to swing clockwise in plan
view along the outer peripheral surface of the bobbin 124.
[0041] The resistance applying part 130 illustrated in Figs. 3 and 4 applies resistance
by friction to the knitting yarn Y pulled out from the bobbin 124. The resistance
applying part 130 is disposed below the bobbin 124. The resistance applying part 130
is formed in a shape opened in the vertical direction so that the knitting yarn Y
can pass therethrough. The resistance applying part 130 includes a contact part 131,
a receiving part 132, and a biasing part 133. Note that, in Figs. 3 and 4, the resistance
applying part 130 is illustrated as a cross-sectional view.
[0042] The contact part 131 is a part that contacts a lower end part of the bobbin 124.
The contact part 131 has a substantially truncated cone shape in which upper and lower
sides are reversed, and is formed in a tubular shape that opens upward and downward.
The contact part 131 has a surface in contact with the bobbin 124 having an inclined
surface shape whose diameter increases upward in cross-sectional view. In the present
embodiment, an angle of the inclined surface with respect to the horizontal direction
is formed to be about 25 degrees. The contact part 131 is formed of, for example,
a film or the like.
[0043] The receiving part 132 is a part that receives a biasing force of the biasing part
133 to be described later. The receiving part 132 is formed to extend downward from
a lower end part of the contact part 131. The receiving part 132 is formed in a substantially
tubular shape that opens vertically. An inner diameter of an opening formed in an
upper part of the receiving part 132 is smaller than an inner diameter of an opening
formed in a lower part.
[0044] The biasing part 133 biases the receiving part 132 upward. As the biasing part 133,
for example, a compression coil spring can be employed. An upper end part of the biasing
part 133 abuts on the upper part (a part around the opening) of the receiving part
132. A lower end part of the biasing part 133 is supported by the support part 110
through an appropriate member (a rotation support part 220 described later in the
present embodiment). The biasing part 133 biases the contact part 131 to press the
lower end part of the bobbin 124 through the receiving part 132.
[0045] The contact part 131 of the resistance applying part 130 is pressed against the lower
end part of the bobbin 124 as described above, so that the resistance by friction
can be applied to the knitting yarn Y between the contact part 131 and the bobbin
124. According to the above configuration, a certain degree of tension can be applied
to the knitting yarn Y passing between the contact part 131 and the bobbin 124 when
the knitting yarn Y is pulled out toward the downstream side in the yarn feeding direction.
Thus, the knitting yarn Y pulled out from the bobbin 124 can be suppressed from overflowing
due to inertia. Furthermore, the resistance applying part 130 (contact part 131, receiving
part 132, and biasing part 133) is formed with an opening that allows the knitting
yarn Y pulled out from the bobbin 124 to pass therethrough as a whole. The knitting
yarn Y applied with the tension by the contact part 131 passes through the opening
and is fed to a side of the lower guide part 112.
[0046] Note that, in the flat knitting machine 1, a configuration of providing an appropriate
tensioner for removing the slack of the knitting yarn Y pulled out from the lower
guide part 112 on the downstream side in the yarn feeding direction of the lower guide
part 112 can be adopted. According to this, the loosening of the knitting yarn Y can
be absorbed by the tensioner even if the loosening occurs in the knitting yarn Y with
the movement of the carriage.
[0047] The yarn length measurement device 200 illustrated in Figs. 4 to 6 can measure a
yarn length of the knitting yarn Y pulled out from the bobbin 124. The yarn length
measurement device 200 is disposed below the bobbin 124 (on the downstream side in
the yarn feeding direction). The yarn length measurement device 200 includes a rotating
member 210, a rotation support part 220, and a rotation amount detection part 230.
[0048] The rotating member 210 illustrated in Figs. 4 and 5 is rotatably provided with respect
to the bobbin 124. The rotating member 210 is formed in a substantially cylindrical
shape with an axial direction oriented in the vertical direction. That is, an internal
space penetrating in the vertical direction is formed in the rotating member 210.
In the present embodiment, from the viewpoint of suppressing vibration during rotation,
the rotating member 210 is formed to have a relatively small vertical length (For
example, the vertical length is smaller than an outer diameter of a disk part 231
to be described later.). The vertical length of the rotating member 210 may be, for
example, 50 mm to 100 mm.
[0049] Furthermore, the rotating member 210 is formed in a shape in which the upper part
is larger in diameter than the lower part. A radius of the upper part of the rotating
member 210 is formed to be smaller than a radius of a part around which the knitting
yarn Y of the bobbin 124 is wound. The rotating member 210 is rotatably supported
by the rotation support part 220 described later about a rotation axis B oriented
in the vertical direction. The rotation axis B is located at a center of the rotating
member 210 in plan view (See Fig. 6(b)).
[0050] The rotating member 210 is provided below the bobbin 124. The rotating member 210
is disposed such that the substantially upper half part is located in the opening
of the resistance applying part 130 (contact part 131, receiving part 132, and biasing
part 133). Furthermore, the rotating member 210 is disposed such that the rotation
axis B substantially coincides with the center in plan view of the bobbin 124 in plan
view. The rotating member 210 includes an introduction part 211 and a lead-out part
212.
[0051] The introduction part 211 introduces the knitting yarn Y from the bobbin 124 to the
downstream side in the yarn feeding direction. The introduction part 211 is formed
so as to open in the horizontal direction at the upper part of the rotating member
210. The introduction part 211 is formed so as to communicate the outer peripheral
surface of the upper part of the rotating member 210 and the internal space of the
rotating member 210.
[0052] As illustrated in Fig. 5, the introduction part 211 is provided at a position deviated
from the rotation axis B. More specifically, the introduction part 211 is located
radially outside the rotation axis B. In the present embodiment, a shortest distance
L (radial distance) from the introduction part 211 to the rotation axis B is formed
to be shorter than 20 mm. Here, the shortest distance L is a distance from a part
of the introduction part 211 located outermost with respect to the rotation axis B
(an outer peripheral surface of the upper part of the rotating member 210) to the
rotation axis B. In the present embodiment, the shortest distance L is the radius
of the upper part of the rotating member 210.
[0053] The lead-out part 212 leads out the knitting yarn Y introduced from the introduction
part 211 to the yarn feeding path A on the downstream side in the yarn feeding direction.
The lead-out part 212 is formed to open downward at the lower end part of the rotating
member 210. The lead-out part 212 communicates with the internal space of the rotating
member 210 and is provided on the rotation axis B.
[0054] The rotation support part 220 illustrated in Figs. 4 and 6(a) rotatably supports
the rotating member 210 about the rotation axis B. The rotation support part 220 includes
a through hole penetrating in the vertical direction, and a lower part of the rotating
member 210 is inserted into the through hole. The rotation support part 220 includes
an appropriate bearing (not illustrated) for smoothly rotating the rotating member
210. The rotation support part 220 is fixed to the right surface of the support part
110 so as to be located below the resistance applying part 130. A recess capable of
holding a lower end part of the biasing part 133 is formed on an upper surface of
the rotation support part 220.
[0055] The rotation amount detection part 230 illustrated in Figs. 4 and 6 can detect a
rotation amount of the rotating member 210. The rotation amount detection part 230
is accommodated in the rotation support part 220. The rotation amount detection part
230 includes a disk part 231 and a sensor unit 232.
[0056] The disk part 231 rotates integrally with the rotating member 210. The disk part
231 is formed in a substantially disk shape with a thickness direction oriented in
the vertical direction. The disk part 231 is fixed to the rotating member 210 in a
state where the rotating member 210 is inserted through an opening part at the center
in plan view. As illustrated in Fig. 6(b), an appropriate slit 231a is formed on a
surface of the disk part 231. Note that, in Fig. 6(b), the slit 231a is illustrated
in a part of the surface of the disk part 231, but the slit 231a is formed over substantially
the entire surface (entire circumference) of the disk part 231.
[0057] The sensor unit 232 can detect a change in the surface of the disk part 231 accompanying
the rotation of the disk part 231. The sensor unit 232 constitutes an optical encoder.
Specifically, the sensor unit 232 is an optical sensor capable of detecting a change
in the surface of the disk part 231 by detecting passage of light (for example, infrared
rays) through the slit 231a of the disk part 231 and shielding of light by a part
other than the slit 231a. The rotation amount of the disk part 231 (rotating member
210) can be detected by using a detection result of the sensor unit 232. Note that
the sensor unit 232 is not limited to one that detects a change in the surface of
the disk part 231 by detecting passage or shielding of light, and one that detects
a change in the surface of the disk part 231 by detecting reflection of light applied
to the surface of the disk part 231 can be adopted. Furthermore, the sensor unit 232
is not limited to one that constitutes an optical encoder, and may constitute an encoder
of another type such as a magnetic type. Specifically, the sensor unit 232 is not
limited to an optical sensor, and various sensors capable of detecting a change in
the surface of the disk part 231, such as a magnetic sensor, can be adopted. Furthermore,
the sensor unit 232 is not limited to one that constitutes an encoder, and may constitute
another detection device that can detect a change in the surface of the disk part
231. In addition, the sensor unit 232 may not necessarily detect a change in the surface
of the disk part 231 as long as it can detect the rotation amount of the disk part
231.
[0058] The control unit 300 illustrated in Fig. 2 is for controlling the operation of the
yarn feeding device 100. The control unit 300 includes an arithmetic processing unit
such as a CPU, a storage unit such as a RAM and a ROM, and the like. The storage unit
of the control unit 300 stores various information, programs, and the like used for
controlling the yarn feeding device 100. The control unit 300 is connected to the
drive unit 122 of the buffer device 120 and can control the operation of the drive
unit 122. Furthermore, the control unit 300 is connected to the rotation amount detection
part 230 (sensor unit 232), and can acquire a detection result of the sensor unit
232. Furthermore, the control unit 300 is communicably connected to the control unit
60, and can exchange information with the control unit 60. Note that, in the present
embodiment, an example has been described in which the control unit 300 and the control
unit 60 are separated, but instead of such a configuration, the control unit 300 and
the control unit 60 may be integrally configured.
[0059] Hereinafter, a state of yarn feeding by the yarn feeding device 100 will be described.
[0060] First, the control unit 300 stores the knitting yarn Y in the buffer device 120.
As illustrated in Fig. 3, the control unit 300 pulls out the knitting yarn Y from
the yarn cone 51 and winds and stores the knitting yarn Y around the bobbin 124 by
driving the drive unit 122 (winding part 123). At this time, the control unit 300
can wind a constant amount of the knitting yarn Y around the bobbin 124 by controlling
the operation of the winding part 123 based on the yarn length per turn of the knitting
yarn Y wound around the bobbin 124, a driving amount of the drive unit 122, and the
like. Note that as the yarn length per turn of the knitting yarn Y, an appropriate
value may be input to the control unit 300, or may be calculated by the control unit
300 using information such as a circumference, a diameter, and the like of the bobbin
124 stored in advance.
[0061] As illustrated in Fig. 1, the knitting yarn Y stored in the bobbin 124 is pulled
out from the bobbin 124 with the knitting operation of the flat knitting machine 1.
The yarn length of the knitting yarn Y pulled out from the bobbin 124 is measured
by the yarn length measurement device 200. Note that the measurement of the yarn length
by the yarn length measurement device 200 will be described later.
[0062] The control unit 300 acquires a measurement result of the yarn length of the knitting
yarn Y pulled out from the bobbin 124, and drives the drive unit 122 (winding part
123) based on the measurement result of the yarn length to pull out and wind the knitting
yarn Y around the bobbin 124. Thus, a constant amount of the knitting yarn Y can be
stored in the bobbin 124 by winding the knitting yarn Y of the length of the pulled
out part around the bobbin 124.
[0063] Hereinafter, the measurement of the yarn length by the yarn length measurement device
200 will be described with reference to Fig. 6.
[0064] When the knitting yarn Y is pulled out from the bobbin 124 with the knitting operation
of the flat knitting machine 1, the rotating member 210 rotates clockwise in plan
view with the operation of the knitting yarn Y. More specifically, when the knitting
yarn Y wound around the bobbin 124 is pulled out, the position of the knitting yarn
Y unwound from the bobbin 124 changes so as to swing clockwise in plan view along
the outer peripheral surface of the bobbin 124. With such an operation of the knitting
yarn Y, the introduction part 211 of the rotating member 210 provided at a position
deviated from the rotation axis B is pressed against the knitting yarn Y (See Fig.
6(a)). As a result, the rotating member 210 rotates clockwise in plan view about the
rotation axis B.
[0065] The rotation amount detection part 230 detects a change in the surface of the disk
part 231 that rotates integrally with the rotating member 210. The control unit 300
acquires a detection result of the rotation amount detection part 230, and measures
the yarn length pulled out from the bobbin 124 based on the detection result. The
control unit 300 can measure the yarn length pulled out from the bobbin 124 by, for
example, performing calculation using the rotation amount of the rotating member 210
(the number of turns of the knitting yarn Y pulled out from the bobbin 124) and the
yarn length per turn of the knitting yarn Y wound around the bobbin 124.
[0066] The control unit 300 can store the measured yarn length. Furthermore, the control
unit 300 can measure the yarn length consumed for each knitting operation (e.g., per
loop length) based on the information relating to the number of rotations of the servomotor
40 and the operation of the carriage 20 acquired from the control unit 60.
[0067] The yarn feeding device 100 configured as described above can realize the yarn length
measurement with high accuracy. That is, for example, in the yarn feeding device in
which the optical sensors are disposed at four locations at equal intervals in the
circumferential direction around the bobbin 124, the pull-out amount of the knitting
yarn Y can be measured by detecting the blocking of the light by the knitting yarn
Y to be pulled out by each optical sensor. However, in such a configuration, even
if the optical sensors are disposed at four locations, the yarn passing between the
optical sensors cannot be detected, and thus there is room for improvement in the
accuracy of the yarn length measurement. Furthermore, it is conceivable to increase
the number of optical sensors for the purpose of improving the accuracy of the yarn
length measurement, but in this case, it is conceivable that the cost increases.
[0068] On the other hand, in the yarn feeding device 100 according to the present embodiment,
the rotating member 210 is rotated by the operation of the knitting yarn Y led out
to the yarn feeding path A on the downstream side in the yarn feeding direction, and
thus the yarn length measurement with high accuracy can be realized by detecting the
rotation amount of the rotating member 210. Furthermore, the configuration described
above can realize the yarn length measurement with high accuracy with a simpler configuration
than, for example, the configuration of increasing the number of optical sensors that
detect the knitting yarn Y. Thus, the accuracy of the yarn length measurement can
be improved while suppressing the increase in cost. Furthermore, according to the
configuration of the yarn feeding device 100, the dimension in the radial direction
of the rotation amount detection part 230 can be reduced as compared with the case
of providing the optical sensors around the bobbin 124, and the compactness of the
device can be achieved.
[0069] Furthermore, in the present embodiment, the lead-out part 212 of the rotating member
210 is provided on the rotation axis B. Thus, a load on the knitting yarn Y passing
through the internal space of the rotating member 210 can be reduced.
[0070] Furthermore, in the present embodiment, the introduction part 211 of the rotating
member 210 is formed at a position where the shortest distance L to the position on
the rotation axis B is relatively short (shorter than 20 mm). Thus, in a case where
the pulling out of the knitting yarn Y is stopped (that is, in a case where the operation
of the knitting yarn Y is stopped), the rotating member 210 can be easily suppressed
from continuing rotating due to inertia, and the yarn length measurement with higher
accuracy can be realized.
[0071] Furthermore, in the present embodiment, the yarn length measurement with higher accuracy
can be realized by detecting the change in the surface of the disk part 231 (rotation
amount detection part 230) integrally rotating with the rotating member 210 by the
operation of the knitting yarn Y.
[0072] Note that the disk part 231 according to the present embodiment is an embodiment
of a part to be detected according to the present invention.
[0073] Furthermore, the rotation support part 220 according to the present embodiment is
an embodiment of a predetermined mounting member according to the present invention.
[0074] Although the first embodiment of the disclosure has been described above, the disclosure
is not limited to the above embodiment, and appropriate modifications can be made
within the scope of the technical idea of the disclosure described in the claims.
[0075] For example, in the present embodiment, an example in which the introduction part
211 of the rotating member 210 is formed at a position where the shortest distance
L to the position on the rotation axis B is shorter than 20 mm has been described,
but the present invention is not limited thereto. That is, the shortest distance L
may be 20 mm or more.
[0076] Furthermore, in the present embodiment, an example in which the contact part 131
of the resistance applying part 130 is formed such that the angle of the inclined
surface with respect to the horizontal direction in the cross-sectional view is about
25 degrees has been described, but the present invention is not limited thereto. The
angle of the inclined surface with respect to the horizontal direction may be formed
to be a larger angle (for example, approximately 45 degrees). Furthermore, the angle
of the inclined surface with respect to the horizontal direction may be formed to
be smaller than 25 degrees.
[0077] Furthermore, in the present embodiment, an example in which the contact part 131
of the resistance applying part 130 is formed in a substantially truncated cone shape
in which the upper and lower sides are reversed has been described, but the present
invention is not limited thereto. For example, the contact part 131 may be formed
in a substantially disk shape. In this case, an upper surface of the disk is brought
into contact with a lower end surface of the bobbin 124. Furthermore, in this case,
an opening through which the knitting yarn Y from the bobbin 124 can pass is formed
at the center of the disk.
[0078] Hereinafter, another embodiment (second to sixth embodiments) of the rotating member
210 will be described.
[0079] A rotating member 210A according to a second embodiment illustrated in Fig. 7(a)
is different from the rotating member 210 according to the first embodiment in the
configuration of an introduction part 211. Furthermore, the rotating member 210A is
formed to have a larger dimension in the vertical direction than the rotating member
210 according to the first embodiment.
[0080] The rotating member 210A is formed such that the introduction part 211 opens obliquely
upward. The rotating member 210A is cut out such that a part of an upper outer peripheral
surface faces obliquely upward, and the introduction part 211 is formed on a surface
facing the upward direction. A lead-out part 212 of the rotating member 210A is located
on a rotation axis B of the rotating member 210B, and the introduction part 211 is
located radially outside the rotation axis B. According to the configuration of the
rotating member 210A of the second embodiment, for example, the knitting yarn Y can
be easily introduced to the introduction part 211 even in a case where a distance
between the bobbin 124 and the rotating member 210A becomes large.
[0081] A rotating member 210B according to a third embodiment illustrated in Fig. 7(b) is
formed in a substantially cylindrical shape with an axial direction oriented in the
vertical direction. In the rotating member 210B, an introduction part 211 is formed
so as to open upward on the upper surface, and a lead-out part 212 is formed so as
to open downward on the lower surface. The lead-out part 212 is located on a rotation
axis B of the rotating member 210B, and the introduction part 211 is located radially
outside the rotation axis B. Furthermore, the rotating member 210B is formed with
a path inclined with respect to the vertical direction so as to communicate the introduction
part 211 and the lead-out part 212.
[0082] A rotating member 210C according to a fourth embodiment illustrated in Fig. 7(c)
is formed of a plate-shaped member bent in a substantially L shape. In the rotating
member 210C, an introduction part 211 is formed so as to penetrate a plate surface
facing the horizontal direction, and a lead-out part 212 is formed so as to penetrate
a plate surface facing the vertical direction. The lead-out part 212 is located on
a rotation axis B of the rotating member 210C, and the introduction part 211 is located
radially outside the rotation axis B. According to the above configuration, the rotating
member 210C can be formed relatively easily by making a hole in the plate-shaped member.
[0083] A rotating member 210D according to a fifth embodiment illustrated in Fig. 8(a) includes
a rotating body 213 provided rotatably about a rotation axis B with respect to a bobbin
124, and an arm 214 extending in a horizontal direction from the rotating body 213.
The rotating body 213 is rotatably supported by an appropriate member (for example,
the rotation support part 220). An introduction part 211 of the rotating member 210D
is formed in a tubular shape opening in the vertical direction, and is provided at
a distal end of the arm 214.
[0084] A lead-out part 212 of the rotating member 210D is formed in a tubular shape opening
in the vertical direction, and is provided on the rotation axis B below the rotating
body 213. Note that although the lead-out part 212 is schematically illustrated in
the drawing example, the lead-out part 212 is integrally formed with the rotating
member 210D. As the rotating member 210D according to the fifth embodiment, a rotation
amount detection part 230 (encoder) similar to that of the first embodiment can be
used.
[0085] A rotating member 210E according to a sixth embodiment illustrated in Fig. 8(b) is
different from the rotating member 210D according to the fifth embodiment in the configuration
of an introduction part 211. The rotating member 210E is formed in a hook shape in
which the introduction part 211 can hook a knitting yarn Y. According to the above
configuration, the knitting yarn Y can be easily introduced to the introduction part
211.
[0086] Also with the configurations of the second to sixth embodiments, it is possible to
realize the rotating member in which the lead-out part 212 is provided on the rotation
axis B and the introduction part 211 is provided at a position deviated from the rotation
axis B. The second to sixth embodiments have substantially the same effects as those
of the first embodiment of the present invention.
[0087] Furthermore, the present invention is not limited to the above-described embodiments,
and appropriate modifications can be made within the scope of the technical idea of
the invention recited in the claims.
[0088] For example, in each of the embodiments described above, the buffer device 120 and
the yarn length measurement device 200 are formed separately, but the present invention
is not limited thereto. That is, the buffer device 120 and the yarn length measurement
device 200 may be integrally formed. In this case, for example, a configuration in
which the yarn length measurement device 200 is provided on the bobbin 124 can be
adopted. Furthermore, in a case where the yarn length measurement device 200 is provided
on the bobbin 124, for example, a configuration in which the lead-out part of the
rotating member 210D according to the fifth embodiment and the lead-out part 212 of
the rotating member 210E according to the sixth embodiment illustrated in Fig. 8 are
formed as separate members from the introduction part 211 can be adopted. In this
case, the lead-out part 212 may be rotatably supported by an appropriate member or
may be non-rotatably supported.
[0089] Furthermore, in each of the above embodiments, the lead-out part 212 of the rotating
member 210 is provided on the rotation axis B, but the present invention is not limited
thereto. That is, the lead-out part 212 may be provided at a position deviated from
the rotation axis B. However, from the viewpoint of reducing the load on the knitting
yarn Y, the lead-out part 212 is desirably provided at a position close to the rotation
axis B.
[0090] Furthermore, in each of the above embodiments, the flat knitting machine 1 has been
described as an example of the knitting machine, but the present invention is not
limited thereto, and can be applied to other various knitting machines (for example,
circular knitting machine, warp knitting machine, and the like). That is, the yarn
feeding device 100 according to the present embodiments can be disposed in the yarn
feeding path A of various knitting machines.
[0091] Furthermore, in each of the embodiments described above, an example of measuring
the yarn length by the control unit 300 provided in the yarn feeding device 100 has
been described, but the present invention is not limited thereto. That is, some or
all of the functions of the control unit 300 can be executed by a control unit (for
example, a personal computer or the like) provided separately from the yarn feeding
device 100. For example, the measurement of the yarn length can be executed by a PC
disposed outside the flat knitting machine 1 or the control unit 60.
INDUSTRIAL APPLICABILITY
[0092] The present invention can be applied to a yarn length measurement device capable
of measuring a yarn length of a knitting yarn fed out from a buffer device, and a
buffer device for the knitting yarn.
REFERENCE SIGNS LIST
[0093]
1: Flat knitting machine
100: Yarn feeding device
120: Buffer device
200: Yarn length measurement device