BACKGROUND
1. Field
[0001] The present disclosure relates to an air-jet loom.
2. Description of Related Art
[0002] Japanese National Phase Laid-Open Patent Publication No. 2014-500914 describes an air-jet loom including a weft insertion device and a controller. The
weft insertion device repeatedly performs a weft insertion operation that emits air
from a main nozzle and sub-nozzles to propel a weft and insert the weft into a warp
shed. The direction in which the weft flies when the weft is propelled and inserted
into the warp shed is referred to as a weft insertion direction. The sub-nozzles are
arranged next to one another in the weft insertion direction. The controller controls
the emission of air from the main nozzle and the sub-nozzles.
[0003] In the air-jet loom described in
Japanese Laid-Open Patent Publication No. 6-108345, during each weft insertion operation, a controller controls the sub-nozzles so that
the sub-nozzles emit air sequentially starting from those located at the upstream
side in the weft insertion direction. Further, the controller emits air so that one
of the sub-nozzles emits air at the same time as when the sub-nozzle that is located
at the most downstream side in the weft insertion direction emits air. In other words,
one of the sub-nozzles emits air twice during each weft insertion operation.
[0004] During the weft insertion operation, if the weft flies at a low speed, the time at
which the leading end of the weft reaches its final position will be later than the
expected time. In this case, if the warp shed is closed before the weft reaches the
final position, the transfer of the weft may result in a failure that stops the loom.
In another case, after the leading end of the weft reaches the final position, the
upstream side of the weft in the weft insertion direction may become loose. If the
warp shed is closed when the weft is loose, that is, when the weft is not fully stretched,
a streaked pattern may form in the woven fabric. This will result in the woven fabric
being a defective product. Thus, it is preferred that the speed of the flying weft
be increased or slack of the weft be reduced to assist the weft insertion operation.
[0005] To assist the weft insertion operation, for example, the air emission time of one
or more sub-nozzles may be lengthened. However, when a relatively long air emission
time length has already been set for the sub-nozzles to increase the weft transportation
capacity, it may be difficult to further lengthen the air emission time. As another
example for assisting the weft insertion operation, the number of times air is emitted
may be increased in one or more sub-nozzles. However, this will increase the number
of times a valve opens and closes to emit air from a sub-nozzle and thereby shorten
the life of the valve.
SUMMARY
[0006] This Summary is provided to introduce a selection of concepts in a simplified form
that are further described below in the Detailed Description. This Summary is not
intended to identify key features or essential features of the claimed subject matter,
nor is it intended to be used as an aid in determining the scope of the claimed subject
matter.
[0007] One general aspect of the present disclosure is an air-jet loom including a weft
insertion device configured to unwind a weft wound around a drum by moving a weft
holding pin backward and configured to repeatedly perform a weft insertion operation
that emits air from a main nozzle and sub-nozzles to propel the unwound weft through
an in-reed passage and insert the unwound weft into a warp shed, and a controller
configured to control the emission of air from the main nozzle and the sub-nozzles.
The weft flies when propelled and inserted into the warp shed in a direction referred
to as a weft insertion direction in which the sub-nozzles are arranged next to each
other. The controller is configured to execute relay control during each weft insertion
operation so that the sub-nozzles emit air sequentially starting from those located
at an upstream side in the weft insertion direction. One or more assist nozzles, separate
from the sub-nozzles, are arranged within a weaving width and are configured to emit
air that applies a driving force to the weft in the weft insertion direction. The
emission of air from the one or more assist nozzles is controlled by the controller.
The controller is configured to allow for execution of assist control that emits air
from the one or more assist nozzles in addition to the execution of the relay control
during each weft insertion operation.
[0008] Other features and aspects will be apparent from the following detailed description,
the drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009]
Fig. 1 is a schematic diagram showing an air-jet loom in accordance with a first embodiment.
Fig. 2 is a perspective view showing the air-jet loom of Fig. 1.
Fig. 3A is a timing chart showing opening and closing timings of a main valve and
sub-valves in the air-jet loom of Fig. 1.
Fig. 3B is a timing chart showing opening and closing timings of an assist valve in
the air-jet loom of Fig. 1.
Fig. 4 is a schematic diagram showing an air-jet loom in accordance with a second
embodiment.
Fig. 5A is a timing chart showing opening and closing timings of a main valve, sub-valves,
and a stretch valve in the air-jet loom of Fig. 4.
Fig. 5B is a timing chart showing opening and closing timings of an assist valve in
the air-jet loom of Fig. 4.
Fig. 6A is a timing chart showing opening and closing timings of a main valve and
sub-valves in a modified example.
Fig. 6B is a timing chart showing opening and closing timings of an assist valve in
a modified example.
[0010] Throughout the drawings and the detailed description, the same reference numerals
refer to the same elements. The drawings may not be to scale, and the relative size,
proportions, and depiction of elements in the drawings may be exaggerated for clarity,
illustration, and convenience.
DETAILED DESCRIPTION
[0011] This description provides a comprehensive understanding of the methods, apparatuses,
and/or systems described. Modifications and equivalents of the methods, apparatuses,
and/or systems described are apparent to one of ordinary skill in the art. Sequences
of operations are exemplary, and may be changed as apparent to one of ordinary skill
in the art, with the exception of operations necessarily occurring in a certain order.
Descriptions of functions and constructions that are well known to one of ordinary
skill in the art may be omitted.
[0012] Exemplary embodiments may have different forms, and are not limited to the examples
described. However, the examples described are thorough and complete, and convey the
full scope of the disclosure to one of ordinary skill in the art.
[0013] In this specification, "at least one of A and B" should be understood to mean "only
A, only B, or both A and B."
First Embodiment
[0014] A first embodiment of the present disclosure will now be described with reference
to the drawings. In the description hereafter, the direction in which a weft Y flies
when the weft Y is inserted into a warp shed is referred to as the weft insertion
direction X.
Air-Jet Loom
[0015] As shown in Fig. 1, an air-jet loom 1 includes a weft insertion device 10, one or
more assist nozzles 15b, a final position arrival time sensor 40, a balloon sensor
19, a state detection sensor 45, a middle position arrival time sensor 41, and a controller
16. The air-jet loom 1 of the present embodiment includes multiple, specifically,
three, assist nozzles 15b. The balloon sensor 19 corresponds to a weft detector in
the present embodiment.
Weft Insertion Device
[0016] As shown in Fig. 1, the weft insertion device 10 includes weft insertion nozzles
11, a yarn feeder 12, a weft length measurement-storage device 13, a reed 14, sub-nozzles
15a, a brake 23, and the controller 16.
[0017] The yarn feeder 12 is located at the upstream side of the weft insertion nozzles
11 in the weft insertion direction X. The weft length measurement-storage device 13
includes a winding arm (not shown) that rotates to draw the weft Y from the yarn feeder
12 and wind the weft Y around a drum 17 for storage. The weft insertion nozzles 11
include a tandem nozzle 21, which withdraws the weft Y from the drum 17, and a main
nozzle 22, which inserts the weft Y into an in-reed passage 14a of the reed 14. The
tandem nozzle 21, the brake 23, the weft length measurement-storage device 13, and
the yarn feeder 12 are fixed to, for example, a coupling member such as a frame (not
shown) of the air-jet loom 1 or a bracket coupled to the floor surface.
[0018] As shown in Fig. 2, the main nozzle 22, the sub-nozzles 15a, the three assist nozzles
15b, and the reed 14 are arranged on a sleigh 24. Fig. 2 shows one of the sub-nozzles
15a and one of the three assist nozzles 15b. The main nozzle 22, the sub-nozzles 15a,
the three assist nozzles 15b, and the reed 14 are moved back and forth integrally
with the sleigh 24 in the forward and rearward directions of the air-jet loom 1. The
sub-nozzles 15a and the assist nozzles 15b are each fixed by a support block 25 to
the sleigh 24. The sub-nozzles 15a and the three assist nozzles 15b are located within
a weaving width TL (refer to Fig. 1). As the sleigh 24 moves back and forth, the sub-nozzles
15a and the assist nozzles 15b moved into and out of a warp shed between layers of
warps T within the weaving width TL.
[0019] The reed 14 includes reed blades 14c, each having a guide recess 14b, arranged in
the weft insertion direction X. The in-reed passage 14a extends through the guide
recesses 14b of the reed blades 14c.
[0020] A cutting device (not shown) for cutting the weft Y is arranged between the main
nozzle 22 and the in-reed passage 14a. Thus, if an assist nozzle 15b were to be arranged
outside the weaving width TL, for example, between the main nozzle 15b and the in-reed
passage 14a, the main nozzle 22 would have to be distanced from the in-reed passage
14a to provide space for arrangement of the assist nozzle 15. If the distance between
the main nozzle 22 and the in-reed passage 14a were to be increased, the amount of
air consumed by the main nozzle 14 would have to be increased. In this respect, the
assist nozzles 15b are arranged within the weaving width TL. Thus, the main nozzle
22 does not have to be distanced from the in-reed passage 14a.
[0021] As shown in Fig. 1, the weft length measurement-storage device 13 includes a weft
holding pin 18. The weft holding pin 18 is located near the drum 17. The weft holding
pin 18 is electrically connected to the controller 16.
[0022] The weft insertion device 10 moves the weft holding pin 18 backward to unwind the
weft Y, which is wound around the drum 17. More specifically, when the rotational
angle of the air-jet loom 1 becomes a preset angle, the weft holding pin 18 moves
backward and unwinds the weft Y from the drum 17. The time at which the weft holding
pin 18 unwinds the weft Y is referred to as the weft insertion initiation time.
[0023] The controller 16 then returns the weft holding pin 18 to the position where it was
located prior to the unwinding of the weft Y. The weft holding pin 18 engages the
weft Y unwound from the drum 17 and ends the weft insertion. The time at which the
weft holding pin 18 engages the weft Y is set in accordance with the number of windings
required for the weft Y wound around and stored on the drum 17 to have the length
corresponding to the weaving width TL.
[0024] The brake 23 is located at the downstream side of the drum 17 in the weft insertion
direction X. The brake 23 brakes the flying weft Y before the insertion of the weft
Y ends. The brake 23 brakes the weft Y that flies at a high speed to lower the flying
speed of the weft Y. This lowers the flying speed of the weft Y before the weft holding
pin 18 engages the weft Y. Consequently, the impact on the weft Y is reduced when
the weft holding pin 18 engages the weft Y. The weft holding pin 18 engages the weft
Y when the leading end of the weft Y reaches a final position Pw, which is the insertion
terminal end.
[0025] The main nozzle 22 is connected by a pipe 22a to a main valve 22v. The main valve
22v is connected by a pipe 22b to a main air tank 26. The tandem nozzle 21 is connected
by a pipe 21a to a tandem valve 21v. The tandem valve 21v is connected by a pipe 21b
to the main air tank 26, which is shared with the main valve 22v. The tandem valve
21v may be connected to an air tank that is separate from the main air tank 26. The
main air tank 26 is connected to an air compressor 31, which is installed in a weaving
factory. The main air tank 26 is supplied with compressed air from the air compressor
31.
[0026] When the main valve 22v is open, the main nozzle 22 emits compressed air. When the
main valve 22v is closed, the main nozzle 22 does not emit air. The emission of compressed
air from the main nozzle 22 is started and stopped by opening and closing the main
valve 22v. When the tandem valve 21v is open, the tandem nozzle 21 emits compressed
air. When the tandem valve 21v is closed, the tandem nozzle 21 does not emit air.
The emission of compressed air from the tandem nozzle 21 is started and stopped by
opening and closing the tandem valve 21v.
[0027] The sub-nozzles 15a and the three assist nozzles 15b are arranged within the weaving
width TL in the weft insertion direction X. In Fig. 1, for the sake of simplicity,
the sub-nozzles 15a are represented by white boxes and the assist nozzles 15b are
represented by black boxes. The sub-nozzles 15a are, for example, divided into nine
nozzle groups. Each nozzle group includes two adjacent ones of the sub-nozzles 15a.
In the description hereafter, the nine nozzle groups will be referred to, in order
from the upstream side to the downstream side in the weft insertion direction X, as
the first nozzle group, the second nozzle group, the third nozzle group, the fourth
nozzle group, the fifth nozzle group, the sixth nozzle group, the seventh nozzle group,
the eighth nozzle group, and the ninth nozzle group. The three assist nozzles 15b
include a first assist nozzle, a second assist nozzle, and a third assist nozzle.
The first assist nozzle is located between the two sub-nozzles 15a of the first nozzle
group. The second assist nozzle is located between the first nozzle group and the
second nozzle group. The third assist nozzle is located between the two sub-nozzles
15a of the second nozzle group.
[0028] The assist nozzles 15b are located within the weaving width TL at the upstream side
in the weft insertion direction X. The phrase of "within the weaving width TL at the
upstream side in the weft insertion direction X" refers to region TLa that extends
from the center TLc of the weaving width TL to the upstream weaving end Tle in the
weft insertion direction X. In the present embodiment, the assist nozzles 15b are
arranged between the four sub-nozzles 15a that are located at the most upstream side
in the weft insertion direction X. Thus, a repetitive pattern of one sub-nozzle 15a
followed by one assist nozzle 15b forms three sets of the sub-nozzle 15a and the assist
nozzle 15b from the upstream side in the weft insertion direction X. The region at
the downstream side of these sets in the weft insertion direction X includes all of
the other sub-nozzles 15a. In the air-jet loom 1 of the present embodiment, the assist
nozzles 15b are located within the weaving width TL only at the upstream side in the
weft insertion direction X.
[0029] A sub-valve 32a is connected to each of the first to ninth nozzle groups. Thus, the
weft insertion device 10 includes nine sub-valves 32a. The three assist nozzles 15b
are connected to an assist valve 32b. Thus, the weft insertion device 10 includes
one assist valve 32b. In Fig. 1, for the sake of simplicity, the sub-valves 32a are
represented by white boxes, and the assist valve 32b is represented by a black box.
[0030] In each of the first to ninth nozzle groups, the two sub-nozzles 15a are connected
by corresponding sub-pipes 33a to the same sub-valve 32a. Thus, the weft insertion
device 10 includes eighteen sub-pipes 33a. The three assist nozzles 15b are connected
by corresponding assist pipes 33b to the same assist valve 32b. Thus, the weft insertion
device 10 includes three assist pipes 33b. The sub-valves 32a and the assist valve
32b are connected to the same sub-air tank 34. The assist valve 32b may be connected
to an air tank that is separate from the sub-air tank 34.
[0031] When each sub-valve 32a is open, the corresponding sub-nozzles 15a emit air. The
sub-nozzles 15a emit air that applies a driving force to the weft Y in the weft insertion
direction X. When each sub-valve 32a is closed, the corresponding sub-nozzles 15a
do not emit air. The emission of air from each sub-nozzle 15a is started and stopped
by opening and closing the corresponding sub-valve 32a.
[0032] When the assist valve 32b is open, the assist nozzles 15b emit air. The assist nozzles
15b emit air that applies a driving force to the weft Y in the weft insertion direction
X. Thus, the air-jet loom 1 includes the assist nozzles 15b, which are separate from
the sub-nozzles 15a, to emit air and apply a driving force to the weft Y in the weft
insertion direction X. When the assist valve 32b is closed, the assist nozzles 15b
do not emit air. The emission of air from each assist nozzle 15b is started and stopped
by opening and closing the assist valve 32b.
[0033] The main valve 22v, the tandem valve 21v, the sub-valves 32a, and the three assist
valves 32b are electrically connected to the controller 16. The controller 16 controls
and actuates the main valve 22v, the sub-valves 32a, and the three assist valves 32b
to emit air from the main nozzle 22, the sub-nozzles 15a, and the three assist nozzles
15b. Thus, the controller 16 controls the emission of air from the main nozzle 22,
the sub-nozzles 15a, and the three assist nozzles 15b.
[0034] The emission of air from the main nozzle 22 and the sub-nozzles 15a propels the weft
Y through the in-reed passage 14a and inserts the weft Y into the warp shed. The weft
insertion device 10 performs a weft insertion operation that emits air from the main
nozzle 22 and the sub-nozzles 15a, which propels the unwound weft Y through the in-reed
passage 14a of the reed 14, and inserts the weft Y into the warp shed. The weft insertion
device 10 repetitively performs such a weft insertion operation.
[0035] More specifically, during insertion of the weft Y, the controller 16 sends actuation
signals to the main valve 22v and the tandem valve 21v. Further, during insertion
of the weft Y, the controller 16 sends an actuation signal to each sub-valve 32a.
As a result, the compressed air emitted from the main nozzle 22 acts to start propelling
the weft Y, and the compressed air emitted from the sub-nozzles 15a propels the weft
Y to the final position Pw.
Sensors
[0036] The final position arrival time sensor 40 is positioned to face a downstream region
of the in-reed passage 14a in the weft insertion direction X. The final position arrival
time sensor 40 is located outside the weaving width TL. The final position arrival
time sensor 40 is arranged so that when the weft Y is in a correctly inserted state,
the leading end of the weft Y, which has a length corresponding to an n number of
windings around the drum 17, is located at the detection position of the final position
arrival time sensor 40. The final position arrival time sensor 40 is electrically
connected to the controller 16. The final position arrival time sensor 40 outputs
a weft detection signal when detecting the leading end of the weft Y. The weft detection
signal indicates that the weft Y has reached the final position Pw. Based on the weft
detection signal output by the final position arrival time sensor 40, the controller
16 recognizes a final position arrival time Tw at which the leading end of the weft
Y reaches the detection position of the final position arrival time sensor 40. Thus,
the final position arrival time sensor 40 detects the final position arrival time
Tw at which the leading end of the inserted weft Y reaches the final position Pw.
The final position arrival time sensor 40 outputs the weft detection signal to the
controller 16 so that the controller 16 recognizes the final position arrival time
Tw.
[0037] The balloon sensor 19 detects the weft Y unwound from the drum 17. Thus, the balloon
sensor 19, which is a weft detector, detects information related to the flying motion
of the weft Y before the weft Y reaches the final position Pw. The balloon sensor
19 is included in the weft length measurement-storage device 13. The balloon sensor
19 is located near the drum 17. The balloon sensor 19 is electrically connected to
the controller 16.
[0038] When detecting the weft Y unwound from the drum 17, the balloon sensor 19 sends a
weft unwinding signal to the controller 16. When receiving the weft unwinding signal
for a preset n number of times, the controller 16 returns the weft holding pin 18
to the position where it was located prior to the unwinding of the weft Y. This engages
the weft holding pin 18 with the weft Y unwound from the drum 17 and ends the weft
insertion.
[0039] The state detection sensor 45 detects the state of the weft Y supplied from the yarn
feeder 12. The state detection sensor 45 is located between the yarn feeder 12 and
the drum 17 in the weft insertion direction X. More specifically, the state detection
sensor 45 is located at the upstream side of the drum 17 in the weft insertion direction
X. The weft Y is inserted into the warp shed downstream from the drum 17 in the weft
insertion direction X. Thus, the state detection sensor 45 detects the state of the
weft Y prior to weft insertion. In other words, the state detection sensor 45 detects
information related to the flying motion of the weft Y before the weft Y reaches the
final position Pw.
[0040] The state of the weft Y that the state detection sensor 45 detects is a yarn parameter
related to at least one of yarn mass, yarn diameter, yarn density, yarn surface structure,
yarn fluffing, and yarn material. The state of the weft Y affects the propulsion of
the weft Y when the weft Y flies during weft insertion.
[0041] The state detection sensor 45 is electrically connected to the controller 16. When
detecting the state of the weft Y prior to weft insertion, the state detection sensor
45 sends a state detection signal to the controller 16. Based on the state detection
signal, the controller 16 recognizes the state of the weft Y.
[0042] The middle position arrival time sensor 41 is positioned at the upstream side of
the final position arrival time sensor 40 in the weft insertion direction X facing
the in-reed passage 14a within the weaving width TL. In the present embodiment, the
middle position arrival time sensor 41 is located at the upstream side of the center
TLc of the weaving width TL in the weft insertion direction X. The middle position
arrival time sensor 41 is arranged so that the detection position of the middle position
arrival time sensor 41 is where the leading end of the weft Y is located when the
inserted weft Y is still shorter than the length corresponding to the n number of
windings stored around the drum 17. Thus, the middle position arrival time sensor
41 detects information related to the flying motion of the weft Y before the weft
Y reaches the final position Pw.
[0043] The middle position arrival time sensor 41 is electrically connected to the controller
16. When detecting the leading end of the weft Y, the middle position arrival time
sensor 41 outputs a weft detection signal. Based on the weft detection signal output
by the middle position arrival time sensor 41, the controller 16 recognizes a middle
position arrival time Ti at which the leading end of the weft Y reaches the middle
position arrival time sensor 41. Thus, the middle position arrival time sensor 41
detects the middle position arrival time Ti at which the leading end of the inserted
weft Y reached a predetermined position Pi that is located at an upstream side of
the final position Pw in the weft insertion direction X.
Details of Controller
[0044] The controller 16 includes a processor and storage. The processor is, for example,
a central processing unit (CPU), a graphics processing unit (GPU), or a digital signal
processor (DSP). The storage includes a random-access memory (RAM) and a read-only
memory (ROM). The storage stores program codes or instructions configured to have
the processor execute a process. The storage, or a computer readable medium, includes
any type of medium that is accessible by a general-purpose computer or a dedicated
computer. The controller 16 may be configured by a hardware circuit such as an application
specific integrated circuit (ASIC) or a field programmable gate array (FPGA). The
controller 16, which is processing circuitry, may be one or more processors running
on computer programs, one or more hardware circuits such as ASICs, FPGAs, or the like,
or a combination of these elements.
Relay Control
[0045] During each weft insertion operation, the controller 16 executes relay control so
that the sub-nozzles 15a sequentially emit air starting from those located at the
upstream side in the weft insertion direction X. Thus, the sub-nozzles 15a are nozzles
that emit air during the relay control.
[0046] In the relay control of the present embodiment, the controller 16 emits air from
the nozzle groups in the order of: the first nozzle group, the second nozzle group,
the third nozzle group, the fourth nozzle group, the fifth nozzle group, the sixth
nozzle group, the seventh nozzle group, the eighth nozzle group, and the ninth nozzle
group. The controller 16, for example, starts emitting air from the main nozzle 22
and starts emitting air from the two sub-nozzles 15a of the first nozzle group simultaneously.
The controller 16 may start emitting air from the main nozzle 22 and then start emitting
air from the two sub-nozzles 15a of the first nozzle group.
[0047] In the present embodiment, the controller 16 emits air from the main nozzle 22 and
the sub-nozzles 15a based on the final position arrival time Tw acquired from the
final position arrival time sensor 40. For example, the controller 16 adjusts a propelling
condition C so that the final position arrival time Tw, which is the detection result
acquired from the final position arrival time sensor 40, becomes close to a target
value.
[0048] When, for example, the final position arrival time Tw detected by the final position
arrival time sensor 40 is later than the target time, the controller 16 sets the propelling
condition C to increase the propelling speed of the weft Y so that the final position
arrival time Tw will be advanced in the next weft insertion and be closer to the target
time. When, for example, the final position arrival time Tw detected by the final
position arrival time sensor 40 is earlier than the target time, the controller 16
sets the propelling condition C to decrease the propelling speed of the weft Y so
that the final position arrival time Tw will be delayed in the next weft insertion
and be closer to the target time.
[0049] The storage of the controller 16 stores multiple conditions that can be used as the
propelling condition C. The timing at which air is emitted from the main nozzle 22
and the sub-nozzles 15a is different in each condition. These conditions differ from
one another in the flying speed of the weft Y and are set in advance based on experiments
and the like. The controller 16 controls the emission of air from the main nozzle
22 and the sub-nozzles 15a in accordance with the propelling condition C. The controller
16 sets the propelling condition C based on the final position arrival time Tw to
optimize the final position arrival time Tw during the next insertion of the weft
Y.
[0050] The valve open time of the main nozzle 22 is predetermined and fixed to be the same
in all of the propelling conditions C stored in the storage of the controller 16.
The valve open time of the sub-nozzles 15a is predetermined and fixed to be the same
time in all of the propelling conditions C stored in the storage of the controller
16. In at least one of the propelling conditions C stored in the storage of the controller
16, the valve open time of the main nozzle 22 may differ from that of the other propelling
conditions C. In at least one of the propelling conditions C stored in the storage
of the controller 16, the valve open time of the sub-nozzles 15a may differ from that
of the other propelling conditions C.
Assist Control
[0051] In addition to the relay control, the controller 16 is configured to execute assist
control that emits air from one or more assist nozzles 15b during weft insertion.
In the assist control of the present embodiment, the controller 16 emits air from
the three assist nozzles 15b. Thus, the three assist nozzles 15b are nozzles that
emit air during the assist control. The assist control is executed to assist the weft
insertion operation. The assist control of the present embodiment is executed to increase
the flying speed of the weft Y when there is a delay in the flying motion of the weft
Y during weft insertion.
[0052] In the present embodiment, the controller 16 infers a delay in the flying motion
of the weft Y based on the detection result acquired from the balloon sensor 19, which
is a weft detector. More specifically, the controller 16 determines whether the time
point at which the weft unwinding signal from the balloon sensor 19 is received a
predetermined number of times is later than a predetermined time point. The predetermined
number of times is set as the number of times required for the leading end of the
weft Y to reach a predetermined position set at the upstream side of the final position
arrival time sensor 40 in the weft insertion direction X. In this case, the predetermined
time point is set as the time point at which leading edge of the inserted weft Y reaches
the predetermined position without a delay. Thus, the controller 16 infers whether
there is a delay in the flying motion of the weft Y by determining whether the time
point at which the weft unwinding signal from the balloon sensor 19 is received the
predetermined number of times is later than the predetermined time point. The controller
16 infers that the flying motion of the weft Y is delayed when the time point at which
the weft unwinding signal from the balloon sensor 19 is received the predetermined
number of times is later than the predetermined time point.
[0053] Based on the delay inference result, the controller 16 determines whether to execute
the assist control. The controller 16 executes the assist control when inferring that
there is a delay in the flying motion of the weft Y. More specifically, the controller
16 emits air from the assist nozzles 15b when inferring that there is a delay in the
flying motion of the weft Y. The controller 16 does not execute the assist control
when inferring that there is no delay in the flying motion of the weft Y. More specifically,
the controller 16 does not emit air from the assist nozzles 15b when inferring that
there is no delay in the flying motion of the weft Y. Thus, when the weft insertion
operation is performed in cycles, the relay control and the assist control are both
executed in cycles in which the flying motion of the weft Y is delayed, and only the
relay cycle is executed in cycles in which the flying motion of the weft Y is not
delayed.
[0054] When the flying motion of the weft Y is delayed, the controller 16 emits air from
the assist nozzles 15b in addition to emitting air from the main nozzle 22 and the
sub-nozzles 15a. The timing at which the assist control starts emitting air from the
assist nozzles 15b may, for example, differ from the timing at which the relay control
starts emitting air from the main nozzle 22 and the sub-nozzles 15a.
Operation of Embodiment
[0055] The operation of the above embodiment will now be described.
[0056] Fig. 3A is a timing chart of the relay control showing one example of the opening
and closing timing of each of the main valve 22v and the sub-valves 32a, that is,
the air emission timing of each of the main nozzle 22 and the sub-nozzles 15a. Fig.
3B is a timing chart of the assist control showing one example of the opening and
closing timing of the assist valve 32b, that is, the air emission timing of the three
assist nozzles 15b. Figs. 3A and Fig. 3B show the air emission timing of the main
nozzle 22, the sub-nozzles 15a, and the three assist nozzles 15b during a single weft
insertion operation.
[0057] In Fig. 3A, line M indicates air emission of the main nozzle 22. Lines E1, E2, E3,
and E4 respectively indicate air emission of the first nozzle group, the second nozzle
group, the third nozzle group, and the fourth nozzle group. Fig. 3A does not show
the air emission of the fifth to ninth nozzle groups.
[0058] Time T1 is when the weft holding pin 18 moves backward to start unwinding the weft
Y from the drum 17. Time M1 is when the main nozzle 22 starts emitting air. Times
E2s, E3s, and E4s are when the sub-nozzles 15a of the second nozzle group, the third
nozzle group, and the fourth nozzle group start emitting air. Time M2 is when the
main nozzle 22 stops emitting air. Times E1e, E2e, and E3e are when the sub-nozzles
15a of the first nozzle group, the second nozzle group, and the third nozzle group
stop emitting air. The time at which the sub-nozzles 15a of the fourth nozzle group
stop emitting air is not shown. Line D1 indicate one example of the flying motion
of the weft Y.
[0059] Referring to Fig. 3B, time T2 is when the controller 16 determines whether the time
point at which the weft unwinding signal from the balloon sensor 19 received by the
controller 16 the predetermined number of times is later than the predetermined time
point. Thus, time T2 is when the controller 16 infers whether there is a delay in
the flying motion of the weft Y based on the detection result acquired from the balloon
sensor 19, which is the weft detector. At time T2, when the time point at which the
weft unwinding signal from the balloon sensor 19 is received the predetermined number
of times is later than the predetermined time point, the controller 16 infers that
there is a delay in the flying motion of the weft Y. When inferring that there is
a delay in the flying motion of the weft Y, the controller 16 executes assist control
and emits air from the assist nozzles 15b. Time T3 is when the assist valve 32b opens;
that is, when the three assist nozzles 15b start emitting air. Time T4 is when the
assist valve 32b closes, that is, when the three assist nozzles 15b stop emitting
air.
[0060] The controller 16 is configured to execute assist control that emits air from the
assist nozzles 15b in addition to the relay control during each weft insertion operation.
In the present embodiment, the controller 16 executes the assist control when inferring
that the flying motion of the weft Y is delayed. More specifically, when the flying
motion of the weft Y is delayed, the controller 16 emits air from the three assist
nozzles 15b through the assist control in addition to emitting air from the main nozzle
22 and the sub-nozzles 15a through the relay control. Thus, compared with when only
the relay control is executed and the assist control is not executed, the air emitted
from the three assist nozzles 15b when the relay control and the assist control are
executed acts on the weft Y so that the weft Y flies at a higher speed.
Advantages of First Embodiment
[0061] The above embodiment has the advantages described below.
[0062] (1-1) The air-jet loom 1 includes the one or more assist nozzles 15b, which are separate
from the sub-nozzles 15a, within the weaving width TL to emit air that applies a driving
force to the weft Y in the weft insertion direction X. The controller 16 controls
the emission of air from the one or more assist nozzles 15b. In addition to the relay
control, the controller 16 is configured to execute assist control that emits air
from the one or more assist nozzles 15b during weft insertion.
[0063] This configuration emits air from the one or more assist nozzles 15b, which are separate
from the sub-nozzles 15a that emit air during the relay control. As a result, the
weft insertion operation is assisted without lengthening the air emission time of
the sub-nozzles 15a or increasing frequency of air emission from the sub-nozzles 15a.
[0064] (1-2) The controller 16 infers whether there is a delay in the flying motion of the
weft Y based on the detection result acquired from the balloon sensor 19, which is
the weft detector. The controller 16 executes the assist control when inferring that
there is a delay in the flying motion of the weft Y. With this configuration, when
the controller 16 infers that there is a delay in the flying motion of the weft Y,
air is emitted from the assist nozzles 15b. Thus, when there is a delay in the flying
motion of the weft Y, air is emitted from the assist nozzles 15b to increase the flying
speed of the weft Y. This assists the weft insertion operation without lengthening
the air emission time of the sub-nozzles 15a or increasing frequency of air emission
from the sub-nozzles 15a.
[0065] (1-3) The weft detector is the balloon sensor 19 that detects the weft Y unwound
from the drum 17. Thus, the controller 16 can infer whether there is a delay in the
flying motion of the weft Y from the detection result of the balloon sensor 19 used
to propel the weft Y. This allows the controller 16 to infer whether there is a delay
in the flying motion of the weft Y without increasing components.
[0066] (1-4) The assist nozzles 15b are located within the weaving width TL at the upstream
side in the weft insertion direction X. In comparison with when air is emitted from
the assist nozzles 15b within the weaving width TL at the downstream side in the weft
insertion direction X, the range over which air acts on the weft Y is greater and
the flying speed of the weft Y increased by the assist nozzles 15b is higher when
air is emitted from the assist nozzles 15b within the weaving width TL at the upstream
side in the weft insertion direction X.
[0067] (1-5) In the air-jet loom 1, the assist nozzles 15b are located within the weaving
width TL only at the upstream side in the weft insertion direction X. In the air-jet
loom 1, the weaving width TL is changed at the downstream side in the weft insertion
direction X using the upstream side in the weft insertion direction X as a reference.
When changing the weaving width TL, if the assist nozzles 15b are located within the
weaving width TL at the downstream side in the weft insertion direction X, the positions
of the assist nozzles 15b will have to be adjusted in accordance with the weaving
width TL. In this respect, the assist nozzles 15b in the present embodiment are located
within the weaving width TL only at the upstream side in the weft insertion direction
X. Thus, the positions of the assist nozzles 15b do not have to be adjusted when the
weaving width TL is changed.
Second Embodiment
[0068] A second embodiment of the present disclosure will now be described with reference
to the drawings. Elements of the air-jet loom 1 that have been described in the first
embodiment will not be described below.
[0069] As shown in Fig. 4, the air-jet loom 1 includes a tensioner 50 that applies tension
to the weft Y. The tensioner 50 includes a stretch nozzle 51. The stretch nozzle 51
is located at the downstream side of the final position Pw in the weft insertion direction
X. The stretch nozzle 51 is located at the downstream side of the final position arrival
time sensor 40 in the weft insertion direction X. The stretch nozzle 51 is arranged
on the sleigh 24. The stretch nozzle 51 is moved back and forth integrally with the
sleigh 24 in the forward and rearward directions of the air-jet loom 1.
[0070] The stretch nozzle 51 is connected to a stretch valve 52 by a stretch pipe 53. The
stretch valve 52 is connected to a stretch air tank 54. When the stretch valve 52
is open, the stretch nozzle 51 emits air. When the stretch valve 52 is closed, the
stretch nozzle 51 does not emit air. The emission of air from the stretch nozzle 51
is started and stopped by opening and closing the stretch valve 52.
[0071] The stretch valve 52 is electrically connected to the controller 16. The controller
16 controls and actuates the stretch valve 52 to emit air from the stretch nozzle
51. Thus, the controller 16 controls the emission of air from the stretch nozzle 51.
The controller 16 emits air from the stretch nozzle 51 after the leading end of the
weft Y reaches the final position Pw. The controller 16, for example, starts emitting
air from the stretch nozzle 51 before the leading end of the weft Y reaches a position
corresponding to the stretch nozzle 51 in the weft insertion direction X.
[0072] After the leading end of the weft Y reaches the final position Pw, the stretch nozzle
51 emits air toward the part of the weft Y located at the downstream side in the weft
insertion direction X. The air emitted from the stretch nozzle 51 stretches the downstream
part of the weft Y in the weft insertion direction X and reduces slack of the weft
Y.
[0073] The controller 16 executes relay control during each weft insertion operation. The
relay control is executed in the same manner as the first embodiment and thus will
not be described. The controller 16 executes assist control that emits air from the
assist nozzles 15b in addition to the relay control during each weft insertion operation.
Thus, the assist nozzles 15b are nozzles that emit air during the assist control.
The assist control is executed to assist the weft insertion operation. The assist
control in the present embodiment is executed after the weft Y reaches the final position
Pw to reduce slack of the weft Y at the upstream side in the weft insertion direction
X.
[0074] In the present embodiment, the assist nozzles 15b are located within the weaving
width TL at the upstream side in the weft insertion direction X. In the present embodiment,
the controller 16 executes the assist control after the weft Y reaches the final position
Pw. More specifically, the controller 16 emits air from the assist nozzles 15b after
the weft Y reaches the final position Pw. Thus, after the leading end of the weft
Y reaches the final position Pw, the assist nozzles 15b emit air toward the upstream
part of the weft Y in the weft insertion direction X.
Operation of Second Embodiment
[0075] The operation of the above embodiment will now be described.
[0076] In Fig. 5A, lines E5, E6, E7, E8, and E9 respectively indicate air emission of the
fifth nozzle group, the sixth nozzle group, the seventh nozzle group, the eighth nozzle
group, and the ninth nozzle group. Time E9e is when the ninth nozzle group stops emitting
air. Line S indicates air emission of the stretch nozzle 51. Time Ss is when the stretch
valve 52 opens, that is, when the stretch nozzle 51 starts emitting air.
[0077] Fig. 5B is a timing chart showing the air emission timing of the three assist nozzles
15b. As described above, time T3 is when the three assist nozzles 15b start emitting
air. In the present embodiment, time T3 coincides with time Ss. More specifically,
the stretch nozzle 51 starts emitting air and the three assist nozzles 15b start emitting
air simultaneously. Time T4 is when the three assist nozzles 15b stop emitting air.
In the present embodiment, time T4 coincides with time E9e. More specifically, the
two sub-nozzles 15a of the ninth nozzle group, which is located within the weaving
width TL at the most downstream side in the weft insertion direction X, stop emitting
air and the three assist nozzles 15b stop emitting air simultaneously.
[0078] The controller 16 executes assist control, which emits air from the three assist
nozzles 15b, in addition to relay control during each weft insertion operation. The
controller 16 of the present embodiment executes assist control after the leading
end of the weft Y reaches the final position Pw. Thus, after the leading end of the
weft Y reaches the final position Pw, the three assist nozzles 15b emit air that stretches
the weft Y in the weft insertion direction X and reduces slack of the weft Y.
Advantages of Second Embodiment
[0079] In addition to advantages (1-1) and (1-5) of the first embodiment, the above embodiment
has the advantages described below.
[0080] (2-1) The assist nozzles 15b are located within the weaving width TL at the upstream
side in the weft insertion direction X. The controller 16 executes assist control
after the leading end of the weft Y reaches the final position Pw. With this configuration,
the assist nozzles 15b emit air after the leading end of the weft Y reaches the final
position Pw. Thus, after the leading end of the weft Y reaches the final position
Pw, the assist nozzles 15b emit air to stretch the weft Y in the weft insertion direction
X and reduce slack of the weft Y. This allows slack of the weft Y to be reduced without
lengthening the air emission time of the sub-nozzles 15a or increasing the frequency
of air emission from the sub-nozzles 15a.
[0081] Further, the assist nozzles 15b are located within the weaving width TL at the upstream
side in the weft insertion direction X. This allows the assist nozzles 15b to emit
air toward the part of the weft Y that may become loose, that is, the part located
within the weaving width TL at the upstream side in the weft insertion direction X.
Thus, slack of the weft Y is reduced effectively.
[0082] (2-2) The air-jet loom 1 includes the tensioner 50. The tensioner 50 includes the
stretch nozzle 51 that is arranged at the downstream side of the final position Pw
in the weft insertion direction X and emits air toward the weft Y. The controller
16 controls the emission of air from the stretch nozzle 51. The controller 16 starts
emitting air from the stretch nozzle 51 and starts emitting air from the assist nozzles
15b simultaneously.
[0083] With this configuration, the air emitted from the assist nozzles 15b and the air
emitted from the stretch nozzle 51 both stretch the weft Y simultaneously. This further
reduces slack of the weft Y. The time at which the assist nozzles 15b start emitting
air is matched with that of another nozzle. This facilitates control of the timing
for starting air emission.
[0084] (2-3) The controller 16 stops emitting air from the sub-nozzles 15a that are located
within the weaving width TL at the most downstream side in the weft insertion direction
X and stops emitting air from the assist nozzles 15b simultaneously.
[0085] This configuration lessens damages that may be inflicted to the weft Y in comparison
with when the sub-nozzles 15a located within the weaving width TL at the most downstream
side in the weft insertion direction X stops emitting air as the assist nozzles 15b
continue to emit air afterwards. Further, the time at which the assist nozzles 15b
stop emitting air is matched with that of another nozzle. This facilitates control
of the timing for stopping air emission.
[0086] (2-4) To reduce slack of the weft Y, the air emission time of one or more sub-nozzles
15a located within the weaving width TL at the upstream side in the weft insertion
direction X may be lengthened. In this case, however, the one or more sub-nozzles
15a located within the weaving width TL at the upstream side in the weft insertion
direction X will have to continuously emit air from immediately after weft insertion
starts to after the leading end of the weft Y reaches the final position Pw. This
increases the amount of air emitted from the one or more sub-nozzles 15a located within
the weaving width TL at the upstream side in the weft insertion direction X. In this
respect, in the present embodiment, the sub-nozzles 15a located within the weaving
width TL at the upstream side in the weft insertion direction X emits air only immediately
after weft insertion. This decreases the amount of air emitted from the sub-nozzles
15a located within the weaving width TL at the upstream side in the weft insertion
direction X.
Modified Examples
[0087] The above embodiments may be modified as described below. The above embodiments and
the following modified example can be combined as long as there is no technical contradiction.
[0088] In the first embodiment, the controller 16 may infer whether there is a delay in
the flying motion of the weft Y based on the detection result acquired from the middle
position arrival time sensor 41. In this case, the middle position arrival time sensor
41 corresponds to a weft detector that detects information related to the flying motion
of the weft Y before the weft Y reaches the final position Pw. In this modified example,
in the same manner as the example illustrated in Figs. 3A and 3B, air is emitted from
each of the main nozzle 22, the sub-nozzles 15a, and the one or more assist nozzles
15b. In this modified example, at time T2 shown in Fig. 3B, the controller 16 infers
whether there is a delay in the flying motion of the weft Y based on the detection
result acquired from the middle position arrival time sensor 41, which is the weft
detector. When the controller 16 infers that there is a delay in the flying motion
of the weft Y at time T2, the controller 16 executes assist control that emits air
from the assist nozzles 15b.
[0089] In addition to advantages (1-1), (1-2), (1-4), and (1-5) of the first embodiment,
the above modified example has the advantage described below.
[0090] The weft detector is the middle position arrival time sensor 41 that detects the
middle position arrival time Ti at which the leading end of the inserted weft Y reaches
the predetermined position Pi located at the upstream side of the final position Pw
in the weft insertion direction X. The middle position arrival time sensor 41, which
detects the leading end of the inserted weft Y, allows the position of the weft Y
in the weft insertion direction X to be detected with further accuracy. Thus, the
controller 16 can infer a delay in the flying motion of the weft Y with higher accuracy.
[0091] In the above modified example, the state detection sensor 45 may be omitted from
the air-jet loom 1.
[0092] In the first embodiment, the controller 16 may infer whether there is a delay in
the flying motion of the weft Y based on the detection result acquired from the state
detection sensor 45. In this case, the state detection sensor 45 corresponds to a
weft detector that detects information related to the flying motion of the weft Y
before the weft Y reaches the final position Pw. In this modified example, as illustrated
in Figs. 6A and 6B, air is emitted from each of the main nozzle 22, the sub-nozzles
15a, and the more or more assist nozzles 15b. The example illustrated in Figs. 6A
and 6B differs from the example illustrated in Figs. 3A and Fig. 3B in the air emission
timing of the assist nozzles 15b. In this modified example, at time T2 shown in Fig.
6B, the controller 16 infers whether there is a delay in the flying motion of the
weft Y based on the detection result acquired from the state detection sensor 45,
which is the weft detector. When the controller 16 infers at time T2 that there is
a delay in the flying motion of the weft Y, the controller 16 executes assist control
that emits air from the assist nozzles 15b. More specifically, the controller 16 emits
air from the assist nozzles 15b when a delay in the flying motion of the weft Y can
be expected.
[0093] In addition to advantages (1-1), (1-2), (1-4), and (1-5) of the first embodiment,
the above modified example has the advantage described below.
[0094] The weft detector is the state detection sensor 45 that detects the state of the
weft prior to weft insertion. The flying speed of the inserted weft Y varies in accordance
with the state of the weft Y. A delay in the state of the weft Y may be inferred from
the state of the weft Y. Thus, the controller 16 can infer a delay in the flying motion
of the weft Y with higher accuracy.
[0095] In the above modified example, the middle position arrival time sensor 41 may be
omitted from the air-jet loom 1.
[0096] At least one of the state detection sensor 45 and the middle position arrival time
sensor 41 may be omitted from the air-jet loom 1 in the above embodiments.
[0097] The middle position arrival time sensor 41 may be located at a position corresponding
to the center TLc of the weaving width TL or at a position located at the downstream
side of the center TLc of the weaving width TL in the weft insertion direction X.
[0098] In the first embodiment, the positions of the assist nozzles 15b may be changed.
For example, the assist nozzles 15b may be located within the weaving width TL at
the downstream side in the weft insertion direction X or be located within the weaving
width TL at the center TLc in the weft insertion direction X. The phrase of "within
the weaving width TL at the downstream side in the weft insertion direction X" refers
to a region that extends from the center TLc of the weaving width TL to the downstream
weaving end in the weft insertion direction X. The assist nozzles 15b may be located
at two or more of the upstream side, the center TLc, and the downstream side within
the weaving width TL in the weft insertion direction X.
[0099] In each of the above embodiments, the quantity of the sub-nozzles 15a in the weft
insertion device 10 may be changed as long as there are two or more. The quantity
of the assist nozzles 15b in the weft insertion device 10 may be changed. The quantity
of the groups of sub-nozzles 15a in the weft insertion device 10 may be changed. The
quantity of the sub-nozzles 15a included in each group may be changed. When the weft
insertion device 10 includes the assist nozzles 15b, the assist nozzles 15b may be
divided into groups. In this case, each group may include any quantity of the assist
nozzles 15b. The quantity of the sub-valves 32a may be changed in accordance with
the quantity of the sub-nozzles 15a. The quantity of assist valves 32b may be changed
in accordance with the quantity of the assist nozzles 15b.
[0100] In the second embodiment, the controller 16 does not have to start emitting air from
the stretch nozzle 51 and the assist nozzles 15b simultaneously. The assist nozzles
15b may start emitting air at the same time as when another nozzle starts or stops
emitting air. Alternatively, the assist nozzles 15b may start emitting air at a time
that differs from when another nozzle starts or stops emitting air.
[0101] In the second embodiment, the controller 16 does not have to stop emitting air from
the assist nozzles 15b simultaneously with when stopping the emission of air from
the sub-nozzles 15a located within the weaving width TL at the most downstream side
in the weft insertion direction X. The assist nozzles 15b may stop emitting air at
the same time as when another nozzle starts or stops emitting air. Alternatively,
the assist nozzle 15b may stop emitting air at a time that differs from when another
nozzle starts or stops emitting air. For example, the controller 16 may stop emitting
air from the assist nozzles 15b at the same time as when stopping emitting air from
the stretch nozzle 51.
[0102] During each weft insertion operation, in addition to the relay control, the controller
16 may execute the assist control that increases the flying speed of the weft Y together
with the assist control that reduces slack of the weft Y. When inferring that there
is a delay in the flying motion of the weft Y, the controller 16 executes the assist
control that increases the flying speed of the weft Y and the assist control that
reduces slack of the weft Y. When inferring that there is no delay in the flying motion
of the weft Y or that a delay cannot be expected, the controller 16 executes the relay
control and the assist control that reduces slack of the weft Y, but does not execute
the assist control that increases the flying speed of the weft Y. In this case, the
one or more assist nozzles 15b emitting air during the assist control that increases
the speed of the flying weft Y may be the same as or differ from the one or more assist
nozzles 15b emitting air during the assist control that reduces slack of the weft
Y