JP2969906B2 - Weft processing equipment in jet looms - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an apparatus for removing abnormal weft yarn injected and inserted from a main weft insertion nozzle from a woven fabric.

[Conventional technology]

Japanese Patent Application Laid-Open No. Sho 62-215047 discloses a weft processing apparatus for removing abnormal wefts that have caused a weft insertion error in a jet room from a woven fabric. In this conventional device, the abnormal weft inserted into the weft and the subsequent weft are connected without cutting, and the abnormal weft driven into the weave with the subsequent weft as a clue from the inside of the warp opening to the side of the weft insertion start side. The drawer is designed to be removed. A take-up roller pair is also installed at the weft insertion end side, and the cut yarn piece that has been cut off in the middle of the abnormal weft and remains in the warp opening is pulled out from the warp opening by the take-up roller pair at the weft insertion end side. It has become so.

[Problems to be solved by the invention]

However, when the cut yarn piece is pulled out and removed from the inside of the warp opening by the pull-out roller pair at the weft insertion end side, the cutting position of the weft is unknown. I do not know if it will be removed. In particular, in the conventional apparatus, the length of the thread piece on the downstream side of the pull-out roller pair cannot be grasped, and the total length of the cut thread piece cannot be measured.

Therefore, there is a possibility that all of the cut thread pieces in the warp shed may not be pulled out and removed, and if a drawer removal error has occurred, the cut thread pieces may be added to the woven fabric even if an attempt is made to automatically resume the operation of the loom after the draw-out process of the abnormal weft. May be incorporated.

The present invention realizes complete withdrawal removal of the cut thread pieces by measuring the length of the cut thread pieces on the downstream side of the take-up roller pair at the weft insertion end side to grasp the entire length of the cut thread pieces, It is an object of the present invention to provide a weft processing device that enables automation of restarting operation of a loom without fear of weaving a cut yarn piece into a woven fabric.

[Means for solving the problem]

For this purpose, in the present invention, in a weft handling device in a jet loom having a missed yarn picking-up means and a picked-up amount measuring means on the weft insertion starting end side and the weft insertion end side, respectively, A take-up roller pair for pulling out the yarn pieces cut and separated from the weft from the inside of the warp shed to the side and removing them, and the take-up amount measuring means is sandwiched between the gripping areas of the take-up roller pair on both sides in the weft insertion direction. A pair of thread piece detectors and a rotation amount detector for the take-up roller pair, and the yarn presence / absence detection information from the pair of thread piece detectors and the winding from the rotation amount detector. The gist of the present invention is to measure the length of the thread piece based on the rotation amount information of the roller pair.

[Action]

The yarn piece cut and separated from the abnormal weft is gripped between the take-up roller pairs, and both ends of the yarn piece are wound up toward the take-up roller pair by the rotation of the take-up roller pair. The thread piece detector on the woven cloth side of the take-up roller pair detects the presence or absence of the thread piece end to be taken up and removed from the inside of the warp opening, and the thread piece detector on the suction pipe side of the take-up roller pair takes up. The presence or absence of the end of the thread piece that has passed between the pair of rollers is detected. Therefore, the length of the end of the yarn piece on the woven fabric side with respect to the take-up roller pair is determined from the yarn presence detection information in the yarn piece detector on the woven fabric side with respect to the take-up roller pair and the rotation amount of the take-up roller pair therebetween. Be grasped. Similarly, the length of the end of the yarn piece that has passed through the take-up roller pair is grasped by the yarn presence detection information from the yarn piece detector on the suction pipe side and the rotation amount of the take-up roller pair therebetween. Thereby, the total length of the cut thread piece is measured.

Embodiment An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, the weft measured and stored by the winding type weft measuring and storing device 3 is supplied to the weft insertion main nozzle 2 mounted on one end of the slay 1, The weft is inserted into the weft insertion passage 4a of the modified reed 4 from the weft insertion main nozzle 2 in synchronization with the weft insertion timing. The weft is pulled out from the winding surface 3a around which the weft is wound. The locking pin 5a driven by the electromagnetic solenoid 5 and the winding surface
It is controlled by the intersection with and separation from 3a.

The weft injected from the weft insertion main nozzle 2 is passed on to the relay injection action of the plurality of auxiliary weft insertion nozzles 20 and 20A. The weft inserted weft is detected by a weft detector 6 installed at a predetermined position on the weft insertion end side outside the rearmost weft insertion auxiliary nozzle 20A to determine whether it is within the set machine base rotation angle range. The weft presence / absence detection information from the weft detector 6 is input to the control computer C, and the control computer C selects one of the continuation and stop of the operation of the loom drive motor M based on the weft presence / absence detection information. If the weft insertion is performed normally, the weft is beaten in the woven cloth fell W ₁ of the cloth W by the deformation reed 4. Then, the beaten weft is cut by the electromagnetic cutter 7 on the side of the main nozzle 2 for weft insertion, and the subsequent weaving operation is continued.

When the weft does not reach the position where the weft detector 6 is installed, the control computer C instructs the loom drive motor M to stop operating. After the weft insertion error detection signal is issued, the machine body stops rotating about one time due to inertia. That is, a weft insertion error detection signal is issued while the slay 1 advances from the last retreat position to the woven fabric W side, and after the erroneous yarn is beaten by the woven fabric W, the slay 1 further reciprocates, and It stops just before the beating position shown by the chain line in the figure. Electromagnetic cutter 7 with weft detection signal originating is placed in an inoperative state, miss yarn woven into the cloth fell W ₁ of the cloth W is connected maintained to the main nozzle 2 side weft inserting.

As shown in FIG. 2, a blow nozzle 8 connected to a pressure air supply source (not shown) is located immediately below the weft insertion main nozzle 2.
Is connected so that the injection port 8a is directed in a direction intersecting with the injection area of the main nozzle 2 for weft insertion. A weft introduction guide 9 is connected directly above the weft insertion main nozzle 2, and its inlet 9 a is provided with an ejection port 8 a of a blow nozzle 8 across an ejection area of the weft insertion main nozzle 2.
The stationary blade 10 is interposed between the inlet 9a and the injection port of the main nozzle 2 for weft insertion.

An air guide 11 and a suction pipe 12 are provided behind the outlet 9b of the weft introduction guide 9 so as to be able to swing integrally with the slab 1. The entrance of the air guide 11 and the entrance of the suction pipe 12 are connected to the exit of the weft introduction duct 9. 9b is set on the discharge route. The outlet side of the suction pipe 12 is curved toward a dust box (not shown) installed in front of the swinging area of the sley 1, and a blow nozzle 13 connected to the pressure air supply source is provided at this curved portion. It is connected to point to 12 exits.

A stepping motor 14 is provided behind the swing area of the slay 1.
Is installed, and directly above it is a stepping motor 14
A drive roller 15 operatively connected to the drive roller 15 is provided. An air cylinder 16 is disposed directly above the drive roller 15, and a driven roller 17 is rotatably supported by the support frame 16 a at the tip of the drive rod so as to face the drive roller 15. The driven roller 17 can be pressed against the driving roller 15 by the projecting operation of the air cylinder 16.

A support base frame 18 is supported by a side surface of an air cylinder 16 which constitutes a weft pull-out mechanism together with the stepping motor 14 and the rollers 15 and 17 so as to be rotatable around a support shaft 31 and is formed on a lower side thereof. A guide pin 16b projecting from the support frame 16a is fitted into the arc-shaped guide hole 18a, and a weft detector 19 having a detection arm 19a is mounted on the support base frame 18.

The drive roller 15 and the driven roller 17 are set to oppose each other with the space between the weft introduction guide 9 and the air guide 11 at the time of the last retreat of the slay 1. It is set at a position where it can be swept across between the air guide 11 and the suction pipe 12 at the time of retreat.

As shown in FIGS. 1 and 3, a pair of yarn guides 21 and 22 are provided on the slay 1 on the weft insertion end side with respect to the weft detector 6, and further outside the suction pipe 30 is connected to the slay 1. It is installed so that it can swing integrally. A blow nozzle 32 is connected to the curved portion of the suction pipe 30, and a suction action is generated at the inlet of the suction pipe 30 by the injection action of the blow nozzle 32.

The entrance of one of the yarn guides 21 is widened outward, and the jetting direction of the weft insertion auxiliary nozzle 20A on the weft insertion end side is directed toward the entrance of the yarn guide 21. As a result, most of the jet air from the weft insertion auxiliary nozzle 20A is
Introduced into.

A light projecting element 23A and a light receiving element 24A are arranged on the inner surface of the thread guide 21 so as to face each other, and a rod-shaped lens 2 is provided between the two elements 23A and 24A.
5A is interposed. The rod-shaped lens 25A has a semicircular cross-section, and the light projected from the light projecting element 23A is converged to a parallel light by the rod-shaped lens 25A, and the converged light sweeps the entire cross-sectional area in the thread guide 21. . Light emitting element 23
A, the light receiving element 24A and the rod-shaped lens 25A constitute a thread piece detector 21A.

A similar light projecting element 23B, light receiving element 24B and rod-shaped lens 25B are provided in the thread guide 22, and the light projecting element 23B, light receiving element 24B and rod-shaped lens 25B constitute a thread piece detector 22A.

A stepping motor 26 is installed upward behind the weft insertion end of the slay 1 at the rearmost position, and a drive roller 27 is attached to its output shaft. An air cylinder 28 is installed downward above the stepping motor 26, and a driven rod 29 rotatably supports a driven roller 29. The upper end surface 27a of the driving roller 27 and the lower end surface 29a of the driven roller 29 face each other, and the opposing end surfaces 27a, 29a of the rollers 27, 29 are joined by the projecting operation of the air cylinder 28. The joining area of the rollers 27 and 29 is set between the yarn guides 21 and 22 on the slay 1 at the rearmost position, and the weft reaching the yarn guide 22 through the weft insertion passage 4a is formed by the rollers 27 and 29. It can be held in 29 intervals.

Tapers 27b, 29b are formed at the peripheral edges of the gripping end surfaces 27a, 29a, and when the gripping end surfaces 27a, 29a are joined, the tapered portions 27b, 29b form a V-shaped annular groove.

Blow nozzle 8,13,32 and the air cylinder 16, 28 is the electromagnetic valve _{V 1, V 2, V 3} , V 4, via a V ₅ is connected to the pressure air supply source, each of these electromagnetic valves V ₁ ~V ₅ and the stepping motor 14, 26 receives a command from the control computer C.
The control computer C includes the weft detectors 6, 19 and the yarn piece detector 21.
A, performs a command control of the electromagnetic valve V ₁ ~V ₅ and stepping motor 14, 26 based on the detection signal from 22A.

When a weft insertion error occurs, the control computer C
The weft processing program shown in the flowcharts of FIGS.

When the weft does not reach the installation position of the weft detector 6,
The control computer C controls the electromagnetic cutter 7 and the loom driving motor M based on the weft insertion error detection signal from the weft detector 6.
And an instruction to excite the electromagnetic valves V ₁ and V ₂ . As a result, pressurized air is supplied to the blow nozzles 8 and 13, and between the blow nozzle 8 and the weft introduction guide 9, a weft insertion preventing air flow is generated across the injection area of the weft insertion main nozzle 2, and a suction pipe 12 is provided. A suction air flow is generated on the inlet side of the air.

These airflows are generated until the sley 1 stops at the dashed line position in FIG. 1 (a) under the inoperative state of the electromagnetic cutter 7. Accordingly woven mistakes yarn before W ₁ woven while connected to the main nozzle 2 side weft inserting weft Y ₂ subsequent to miss yarn weft length measuring storage by weft insertion preventing air flow in the machine base inertial operation It is pulled out from the device 3 and is forcibly introduced into the weft introduction guide 9. And the subsequent weft Y ₂
Reaches the suction pipe 12 via the air guide 11, and is blown away toward the dust box by the injection action of the blow nozzle 13. By this jetting action, the weft introduction guide 9
Subsequent weft yarn Y ₂ is tensioned been granted an appropriate tension between the suction pipe 12.

Subsequent to the stop of the machine, the control computer C instructs a reverse operation of the machine by a predetermined amount based on the detection signal from the rotary encoder 33, and as shown in FIG.
Retreats to the last retreat position. The maximum opening condition of the warps T are formed by the recession woven condition of miss yarn Y ₁ by the upper and lower warps T is released. At the conjunction succeeding weft Y ₂ between the weft guiding guide 9 and the air guide 11 is arranged to drive roller 15 and the pressure grip area between the driven roller 17 at the same time, the air guide 11 and suction pipe 12 subsequent weft Y ₂ between are arranged to detect the arm 19a of the rotating sweep area. After machine frame reverses, weft insertion blocking airflow by demagnetization of the solenoid valve V ₁ is extinguished. In this state excitation solenoid valve V _3, the driven roller 17 is pressed against the driving roller 15.

As the driven roller 17 moves downward, the support base frame 18 rotates about the support shaft 31 by the engagement between the guide pin 16b and the guide hole 18a, and the detection arm 19a moves the air guide 11 and the suction pipe 12
And swivel across. At this time, when the succeeding weft Y ₂ does not exist between the roller pair 15, 17 and the suction pipe 12, the detection arm 19a moves integrally with the main body of the weft detector 19, and the weft detector 19 outputs a yarn presence detection signal. It does not emit. When the control computer C cannot obtain the yarn presence detection signal from the weft detector 19 within a predetermined time, the control computer C recognizes the abnormality in the weft processing, and commands the blinking of the alarm lamp 34 and the demagnetization of the electromagnetic valves V ₂ and V ₃ . As a result, the suction air flow is stopped, and the roller pairs 15, 17 are separated from each other.

If a subsequent weft yarn Y ₂ is present between the rollers 15 and 17 and the suction pipe 12, the subsequent weft yarn detection arm 19a is tension Y ₂
And relative rotation with respect to the main body of the weft detector 19,
The weft detector 19 issues a weft presence signal. The control computer C commands the actuation of the stepping motor 14 in response to the detection signal there this weft, subsequent weft yarn Y ₂ rollers 15, 17 holding the rotate. The rotation of the pair of rollers 15 and 17 causes the succeeding weft Y _{2 to} be drawn toward the suction pipe 12. The pulling tension causes the subsequent weft Y ₂ to be cut and separated from the main nozzle 2 by the fixed blade 10, and the cloth fell W ₁ miss yarn Y ₁ of the above is going to be separated from the cloth fell W _1.

The miss yarn Y ₁ pulled out from the cloth fell W ₁ is the roller pair 15, 17
While receiving the gripping will be sucked into the suction pipe 12 side, weft detector 1 as long as the rollers 15 and 17 is grasping a mistake yarn Y ₁
9 outputs a weft presence detection signal to the control computer C. When the output of the weft presence detection signal disappears, the control computer C stops the operation of the stepping motor 14 and instructs the demagnetization of the electromagnetic valves V ₂ and V ₃ . As a result, the roller pairs 15 and 17 are separated from each other and the blow nozzle 13
Injection stops. Then, the control computer C to grasp the drawer length x ₁ mistake yarn Y ₁ from the shed by actuation pulse signal amount with respect to the stepping motor 14 in the weft there detection signal input from the weft detector 19.

In the case of a weft insertion error such that the weft does not reach the weft detector 6, the control computer C sets the measured draw-out length x ₁
Together but the operation of the loom to start if preset weft insertion corresponding value X ₀ or more long, and displays the x ₁ <X ₀ on the display device 35 when not reach the set value X _0, An alarm is issued by an alarm lamp.

If a miss yarn Y ₁ as shown in FIG. 1 (a) has caused a yarn breakage or when the yarn breakage occurs in the weft supply side, detecting the cut yarn piece Y ₃ yarn piece detector 21A, the 22A Is done. In this case, prior to the above-described weft insertion prevention action from the detection of a weft insertion error to the stop of the machine base, the control computer C executes the thread piece detector.
21A, to grasp the yarn breakage miss yarn Y ₁ based on the detection signal from 22A, stops the machine base after performing the weft insertion inhibiting effect similar to the above.

The weft presence detection signals from the thread piece detectors 21A and 22A continue to be input to the control computer C. When the input period of the weft presence detection signal exceeds a predetermined time, the control computer C sends the stepping motor 14, the air cylinder 16 and the roller pair 1 to each other.
The same processing operation as that described above of the weft pulling mechanism on the weft insertion start end composed of 5, 17 is commanded.

When the processing operation of the weft withdrawing mechanism on the weft insertion start end side is completed, the control computer C commands the processing operation of the weft withdrawal mechanism on the weft insertion end side including the stepping motor 26, the air cylinder 28, and the pair of rollers 27 and 29. That is, the electromagnetic valve V ₄ is excited, the gripping end face 29a of the driven roller 29 is pressed against the gripping end face 27a of the drive roller 27. Thereby gripping end surface 27a of the cut yarn piece Y ₃ are rollers 27 and 29, it is gripped between 29a.

After gripping of the cut yarn piece Y ₃ by the roller pair 27, 29 operates the stepping motor 26, rollers 27, 29 gripped by being cut yarn piece Y ₃ is gripped end face 7a, 29a of the peripheral edge of the taper 27b, 29
It is wound on b. Tapered at both ends are both roller within 27 and 29 of the cut yarn piece Y ₃ by the take-up action 27
It is wound on b and 29b.

Before the pair of rollers 27 and 29, that is, the cut yarn piece Y on the warp opening side
End Y _{31 3} receives the detection of the yarn piece detector 21A, the yarn strip detector 21A to the end Y ₃₁ of Itohen Y ₃ passes the thread piece detector 21A yarn there controls the detection signal computer C Output to or,
The other end Y ₃₂ of Itohen Y ₁ passing through the gripping region of the roller pair 27, 29 is subjected to detection of the yarn piece detector 22A. End Y of thread piece Y _3
The thread piece detector 22A outputs a thread presence detection signal to the control computer C until ₃₂ passes through the detection area of the thread piece detector 22A.

When the output of the yarn presence detection signal from both yarn piece detectors 21A and 22A stops, the control computer C starts the stepping motor.
26 with an instruction to deactivation, instructs demagnetization of the electromagnetic valve V _4, instructs demagnetization of the electromagnetic valve V ₅ after a certain time. As a result, the roller pair 27, 29 is separated, and the roller pair 27, 29
Itohen Y ₃ which has been wound Yuku it is accepted to the suction pipe 30 side by the suction action of the suction pipe 30 upward. afterwards,
The suction action in the suction pipe 30 is eliminated.

Control computer C, winding length x ₂ of the end Y ₃₁ of the yarn piece Y ₃ from the actuation pulse amount for the stepping motor 26 of the yarn there detection signal in input from the yarn piece detector 21A in the stepping motor 26 operates after the start ′, And thread detector 2
Stepping motor 26 during input of thread detection signal from 2A
Grasp the winding length x ₃ of the end portion Y ₃₂ of the yarn piece Y ₃ 'from actuation pulse amount for. Then, the winding of the yarn piece detector distance d ₁ and the winding length sum x ₂ and x ₂ 'from 21A to winding start position of the yarn piece end Y _31, thread from the yarn piece detector 22A one end portion Y ₃₂ the distance to the start position preparative d ₂ and the sum x ₃ of the winding length x ₃ 'is calculated. That, x ₂ is x ₃ represents the take-off length of the yarn piece end Y ₃₁ represents a take-off length of the yarn piece end Y _32.

The value obtained by adding the winding diameter d shown in FIG. 6 (b) to the take-up length (x ₂ + x ₃ ) of both yarn pieces Y ₃₁ and Y ₃₂ represents the length of the yarn piece Y ₃ . The control computer C calculates the sum X (= x ₁ + x ₂ + x ₃ +) of the length of the yarn piece Y ₃ and the weft length x ₁ taken at the weft insertion start side.
d) is commanded resume operation if a value corresponding to X ₀ or more weft insertion length which is set in advance, if not reach the X ₀ warning lamp
34 alarm is issued.

x ₁ + x ₂ + x ₃ + d <X ₀
A case where yarn breakage occurs during withdrawal of Y ₁ or cut yarn piece Y _3, part of a part of a miss yarn Y ₁ would resume operation of the loom or cut yarn piece Y ₃ is in this state It is woven into the woven fabric W. However, it is possible to grasp the presence of residual errors yarn Y ₁ or cut yarn piece Y ₃ in the warp shedding because they measure a mistake yarn drawer length of Y ₁ and the length of the cut yarn piece Y _3, Missing thread Y ₁ or cut thread piece Y _{3 in the} warp shed
There is no possibility that the operation of the loom will be restarted by leaving a part of the loom.

When Itohen Y ₃ which has been wound onto the roller 27, 29 is taken over to the suction pipe 30 side, Itohen Y ₃ is detected by the yarn piece detector 22A, there yarn from the yarn piece detector 22A If the detection signal cannot be obtained within the predetermined time, the control computer C displays the respective measurement quantities x ₁ , x ₂ , x ₃ , X and the set value X ₀ on the display device 35, and displays the measurement value by the alarm lamp 34. Give an alarm.

Itohen Y ₃ is the case that caught the yarn guide 21 the control computer C can not be obtained yarn absence detection information from the yarn piece detector 22A. If the thread absence detection information cannot be obtained within a predetermined time, the control computer C displays and warns each length measurement in the same manner as described above.

1 (b) and 4 (b) show a state in which the weft breaks before the weft insertion main nozzle 2 and a yarn feeding error occurs. In this case, the processing operations of the weft processing device on the weft insertion start end side and the weft processing device on the weft insertion end side are performed according to the weft processing program shown in FIGS. 7A to 7D, but the loom is not restarted.

The present invention is, of course, not limited to the above-described embodiment, but may be, for example, the embodiment shown in FIGS.

In this embodiment, thread guides 21 and 22 having thread piece detectors 21A and 22A, a stepping motor 26, an air cylinder (not shown) having driven rollers, and a suction pipe 30 are provided on a support base 36, The support base 36 is supported by an air cylinder 37 so as to be movable in the reciprocating direction of the sley 1. Support base 36 is always in the position of Figure 8 capable of introducing the yarn piece Y ₃ that yarn guide 21 come to Hihashi is held, retracted position of the support base 36 is sley 1 at the time of withdrawal of the Itohen Y ₃ Moved to the side. Yarn piece Y ₃ This movement is drawn in a direction having a large angle relative to the front W ₁ weave, which facilitates withdrawal of the Itohen Y _3. In addition, the support base 36 to the rearmost position side of the slay 1
The movement is carried out while gripping the Itohen Y ₃ between rollers 27 and 29.

Further, in the present invention, a pair of yarn pieces detector 21A, the yarn piece Y ₃ between 22A is gripped by the peripheral surface of the roller pair in the clamshell, so as to draw the two ends of the thread pieces to between the peripheral surface of the roller pair The embodiment described above is also possible.

〔The invention's effect〕

As described in detail above, the present invention takes up both end portions of a yarn piece between the pair of yarn take-up rollers by using a take-up roller pair between a pair of yarn piece detectors installed on the weft insertion end side, and from both yarn piece detectors. Since the length of the cut thread piece is measured based on the thread presence information and the rotation amount information of the take-off roller pair,
The length of each end of the yarn piece before and after the take-up roller pair can be linked to the rotation amount information of the take-up roller pair to measure the length. With such a length measurement method, the cut yarn piece can be taken from within the warp opening. The length of the thread piece can be accurately measured while being pulled out and removed. Therefore, it is possible to prevent the weaving from being restarted in a state in which a part of the cut thread remains, and to achieve an excellent effect that automation of restarting the operation of the loom is achieved.

[Brief description of the drawings]

1 to 7 show an embodiment of the present invention.
FIG. 1 (a) is a schematic plan view when a yarn break occurs in a weaving width area, and FIG. 1 (b) is a schematic plan view near a slay when a yarn break occurs in front of a weft insertion main nozzle. FIG. 2 is a perspective view showing a weft withdrawing mechanism on the weft insertion start end side, FIG. 3 is an enlarged front sectional view of a main part showing a state in which the tip of the cut yarn piece has reached the inside of the suction pipe, and FIG. FIG. 4B is a schematic plan view showing a state where the slay is at a rearmost position, and FIG. FIG. 5 (b) is an enlarged front sectional view of a main part showing a state in which a thread piece is gripped, and FIG.
FIG. 6A is a cross-sectional view taken along a line A, FIG. 6A is an enlarged front sectional view of a main part showing a state in which a yarn piece is wound around a roller and a peripheral surface, and FIG. 7 (a) to 7 (d) are flowcharts showing a weft processing program, and FIGS. 8 and 9 are schematic plan views showing another example of the present invention. A stepping motor 26 and an air cylinder 28, a winding roller pair 27 and 29, a yarn piece detector 2 which constitute a weft withdrawing mechanism.
1A, 22A, control computer C serving as length measuring means.

Claims (1)

(57) [Claims] 1. A weft handling device in a jet loom having a missed yarn take-up means and a take-off amount measuring means at a weft insertion start end and a weft insertion end side, respectively. A take-up roller pair for pulling out and removing the yarn pieces cut and separated from the warp shedding to the side and removing the take-up amount measuring means on both sides in the weft insertion direction with the take-up amount measuring means sandwiched between the gripping areas of the take-up roller pair. A pair of thread piece detectors installed and a rotation amount detector of the winding roller pair, and yarn presence / absence detection information from the pair of thread piece detectors and the winding roller from the rotation amount detector. A weft processing device in a jet loom that measures the length of the yarn piece based on the rotation amount information of the pair.