JPH08120543A - Control of weft insertion in jet loom and device therefor - Google Patents

Abstract

PURPOSE: To provide a method for controlling weft insertion in a jet loom and a device therefor capable of preventing yarn cutting at the completion of the weft insertion while securing good weft insertion. CONSTITUTION: This method for controlling weft insertions in a jet loom and a device therefor comprise detecting a weft yarn unrolled by drawing out from a yarn winding surface 1-2 of a weft yarn length measuring and storing device 1 by a weft yarn unrolling detecting device 4, sending this detected signal to an arithmetic circuit for comparing difference 5. The difference between the output timing of the detected signal and a standard drawing out timing is sent by the arithemetic circuit for comparing difference 5 to a braking timing controlling circuit 6. A braking wire 11 driven by a rotary solenoid 10 actuates braking to the weft yarn Y in the state of demagnetization of the rotary solenoid. The braking timing controlling device 6 controls the demagnetization timing of the rotary solenoid 10 in accordance with the magnitude of the difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weft insertion control method and device in a jet loom.

[0002]

2. Description of the Related Art At the end of flight of a weft in a jet loom, the weft is prevented from being pulled out from the weft length measuring and storage device. The weft is prevented from being pulled out by engagement between a winding surface and a weft locking pin. Since such a weft pull-out preventing function suddenly stops the flight of the high-speed flying weft to increase the tension, the weft may be cut.

Japanese Unexamined Patent Publication No. 56-93659 discloses a device for preventing weft cutting when the weft drawing is blocked. In this conventional device, a braking shoe is arranged near the bobbin winding surface, and the braking shoe contacts the bobbin winding surface in synchronization with the rotation of the loom main shaft. As a result, the weft yarn pulled out from the yarn winding surface is braked, and the weft yarn withdrawing speed, that is, the weft flying speed is reduced. The timing of applying the braking is performed shortly before the weft withdrawal is prevented, and a sudden increase in the weft tension when the withdrawal is prevented is suppressed. The method of synchronizing the braking timing with the rotation of the main shaft of the loom has the following drawbacks. Even in the case of the same type of weft yarn, the flying speed varies with each weft insertion, and the timing at which the weft locking pin prevents the weft from being pulled out varies with each weft insertion. If the winding speed on the winding surface is unwound without being constrained, if the flying speed varies, the unwinding speed of the winding thread that slides out on the winding surface also varies, and the winding thread There is a risk that it will escape from the braking action of the braking shoe that contacts the surface. In order to avoid this, as disclosed in the embodiment of the conventional device, the winding yarn may be constrained and guided by the weft retaining pin that moves in the weft withdrawing direction. Is quite complicated.

In the apparatus disclosed in Japanese Patent Laid-Open No. 2-99644,
The electromagnetic solenoid and its armature form a weft braking device.

[0005]

It is disclosed that the braking timing can be adjusted according to the weft braking device composed of the electromagnetic solenoid and its armature. However, the method of setting the braking timing is not disclosed at all, and the proper setting of the braking timing is unknown.

Japanese Unexamined Patent Publication (Kokai) No. 60-9945 and Japanese Unexamined Patent Publication (Kokai) No. 3-
Japanese Patent No. 279440 discloses a weft retracting device, but these devices do not have the effect of braking the weft because the weft retracting is performed after the beating.

It is an object of the present invention to provide a method and a device that allow the setting of proper braking timing that results in good weft insertion.

[0008]

To this end, in the invention of claim 1, the pull-out timing detecting means detects the pull-out timing of the preset pull-out amount of the weft drawn from the weft measuring and storing device, and the pull-out timing detecting means. The detection pull-out timing detected by the above-mentioned and the preset reference pull-out timing are compared by the comparison difference calculation means to make a difference, and the braking timing control means controls the operation timing of the weft braking means according to the difference. I chose

According to the second aspect of the present invention, weft braking means for braking the weft between the weft measuring and storing device and the main weft inserting nozzle, and the weft drawn from the weft measuring and storing device are set in advance. Withdrawal timing detecting means for detecting the withdrawal timing of the withdrawal amount, comparison difference calculating means for comparing the detected withdrawal timing detected by the withdrawal timing detecting means with a preset reference withdrawal timing, and providing the difference, A weft braking device is provided which comprises a braking timing control means for controlling the operation timing of the weft braking means in accordance with the difference between the detected withdrawing timing and the reference withdrawing timing obtained by the difference calculating means.

[0010]

The detected withdrawal timing detected by the withdrawal timing detecting means is compared with the reference withdrawing timing by the comparison difference calculating means. The braking timing control means controls the operation of the weft braking means at an operation timing according to the difference obtained by the comparison. Control of the operation timing based on the difference between the detected pull-out timing and the reference pull-out timing enables proper weft braking.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment embodying the present invention will now be described with reference to FIGS.
It will be described with reference to FIG. Reference numeral 1 denotes a winding type weft measuring and storing device, in which a weft Y is wound and stored on a yarn winding surface 1-2 by rotation of a yarn winding tube 1-1. The weft yarn Y wound and stored on the yarn winding surface 1-2 is released from the locking action of the weft locking pin 2-1 driven by the electromagnetic solenoid 2 by the jet action of the weft-insertion main nozzle 3. Be withdrawn.
The electromagnetic solenoid 2 is subjected to the excitation / demagnetization control of the extraction / unwinding control circuit 17. The extraction / unwinding control circuit 17 excites the electromagnetic solenoid 17 based on the machine base rotation angle information obtained from the rotary encoder 15 for detecting the machine base rotation angle.

The weft Y ejected from the weft-inserting main nozzle 3 is weft-inserted into the warp opening, and the weft-inserting auxiliary nozzle 1
It jets in the warp opening by the jetting action of 6. Curve E in FIG. 3 represents the amount of weft Y drawn. The machine base rotation angle θ ₀ is a time point at which the electromagnetic solenoid 2 is excited, and the excitation causes the weft thread locking pin 2-1 to separate from the thread winding surface 1-2. That is, the machine rotation angle θ ₀ represents the weft insertion start timing.
When the weft thread locking pin 2-1 engages with the thread winding surface 1-2, the weft thread is prevented from being pulled out. In this embodiment, the weaving width is 3 windings (length L).

A reflective photoelectric sensor type weft unwinding detector 4 is installed near the bobbin winding surface 1-2. The weft unwinding detector 4 detects the unwound yarn drawn and unwound from the bobbin winding surface 1-2, and the detection signal is sent to the comparison difference calculation circuit 5 and the unwound unwinding control circuit 17. The comparison difference calculation circuit 5 determines whether or not the detection signal is input in the range between the machine base rotation angles θ ₂ and θ ₃ shown in FIG. Draw-out and unwind control circuit 17
Determines whether or not the detection signal is input in the range between the machine rotation angles θ ₄ and θ ₅ . The reason for determining the presence / absence of input is to limit the rotation angle range of the machine base to avoid detection of objects other than weft threads such as cotton wool. The comparison difference calculation circuit 5 is signal-connected to the braking timing control circuit 6. A rotary encoder 15 is signal-connected to the comparison difference calculation circuit 5 and the braking timing control circuit 6.

In front of the weft measuring and storing device 1, yarn guide rings 7, 8 and 9 are arranged in series. A rotary solenoid 10 is disposed below the weft path between the weft measuring and storing device 1 and the yarn guide ring 7. A braking wire 11 is fixed to the output shaft 10-1 of the rotary solenoid 10. The tip portion of the braking wire 11 is curved and inverted, and the yarn guide ring 8 is included in the rotation region of the curved portion around the output shaft 10-1.

The output shaft 10-1 is rotationally biased to the left in FIG. 2 by a torsion spring 12. Position restricting pieces 13 and 14 are disposed on the left and right of the output shaft 10-1, and the turning range of the braking wire 11 is restricted between the position restricting pieces 13 and 14. When the rotary solenoid 10 is excited, the braking wire 11 is pivotally arranged against the spring action of the torsion spring 12 to the position shown by the chain line in FIG. Excitation / demagnetization of the rotary solenoid 10 is performed by a command from the braking timing control circuit 5.

FIG. 4 shows a comparison difference calculation circuit 5 and a braking timing.
Excitation / demagnetization of the rotary solenoid 10 by the control circuit 6
It is a flowchart which controls. Machine rotation angle θ is θ
₁Then, the braking timing control circuit 6 becomes
Excite the noid 10. θ = θ₁Is the winding on the thread winding surface 1-2
The machine base where the knitting thread is released from the locking action of the weft thread locking pin 2-1.
Rotation angle θ = θ₀It is the angle before. Rotary soleno
The excitation of the id 10 causes the braking wire 11 to move to the solid line position in FIG.
To the position of the chain line, between the yarn guide rings 7 and 9
The weft yarn Y is released from the engagement with the braking wire 11. Machine stand
Rotation angle θ is θ ₀Then, the pull-out and unwind control circuit 17
Excites the electromagnetic solenoid 2. This excitation causes the weft thread
The stop pin 2-1 is separated from the bobbin winding surface 1-2, and on the bobbin winding surface 1-2.
Is released from the locking action of the weft locking pin 2-1.
You. At the same time, the main nozzle 3 for weft insertion jets and the thread is wound.
The winding yarn on the surface 1-2 is pulled out and unwound. This drawer
The unwinding is detected by the weft unwinding detector 4. Figure 3
The loose waveforms P and Pn are detected by the weft unwinding detector 4.
Represents the detected waveform of the weft. Represented by a pulse waveform
The weft unwinding detection signals P and Pn are used for comparison difference calculation circuit 5 and pulling.
It is sent to the output / unwind control circuit 17. Withdrawal and release control times
Path 17 is the machine rotation angle [θ_Four, Θ_Five] In the range
The electromagnetic solenoid 2 is activated in response to the input of the yarn unwinding detection signal P.
Degauss. Due to this demagnetization, the weft thread locking pin 2-1 causes the bobbin winding surface to
It engages with 1-2, and the withdrawal of the winding thread is blocked.

The comparison difference calculation circuit 5 determines the output timing θx of the weft unwinding detection signal Pn sent to the nth time (third time in this embodiment) based on the machine base rotation angle information from the rotary encoder 15. Figure out The output timing θx is a preset weft pull-out unwinding amount (in this embodiment, approximately 2 L /
It is the timing of drawing out 3). The weft unwinding detector 4 serves as pull-out timing detection means for detecting the pull-out timing θx of the set pull-out amount of the weft drawn from the weft measuring and storing device 1.

The comparison difference calculation circuit 5 has a preset reference value.
Withdrawal timing (indicated by θn in Fig. 3) and detection withdrawal
Then, the difference from the timing θx Δθn = θx−θn is calculated.
You. The reference drawing timing θn is sent to the nth time.
Average of past actual data of incoming weft unwinding detection signal Pn
The value is adopted. The comparison difference calculation circuit 5 calculates this
The difference Δθn is output to the braking timing control circuit 6. System
The dynamic timing control circuit 6 controls the difference Δθn and the preset difference.
Compare the magnitude with α. When Δθn <α, braking timing
The turning control circuit 6 has a machine base rotation angle θy = θx + K.₁(K₁
Is definite, the rotary solenoid 10 is demagnetized.
When α ≦ Δθn, the braking timing control circuit 6 turns the machine base.
Rolling angle θy = θx + K₁・ At the time of Δθn, the rotary
Degauss Noid 10. The weft unwinding detection signal Pn turns on
Turning angle (θ₂, Θ₃] If the output is not within the range
Indicates that the braking timing control circuit 6 is the machine rotation angle θy = θ.
₃+ K ₁(Θ₃-Θn) + K₂At the time of rotary Soleno
Degauss Id 10. That is, θy is the braking on the weft Y
Indicates the start time. Curve C in FIG. 3 is the rotary solenoid 1
Represents 0 excitation and demagnetization.

The demagnetization of the rotary solenoid 10 causes the braking wire 11 to be rotated from the chain line position in FIG. 2 to the solid line position by the spring action of the torsion spring 12. The weft yarn Y passing through the yarn guide rings 7, 8 and 9 is bent by the rotational arrangement of the braking wire 11 from the chain line position to the solid line position.
By this bent shape, the weft Y is braked, and the flying speed of the weft Y is reduced. When the weft insertion is normally performed, the arrival of the front end of the weft yarn Y is detected by the weft detector 18 on the weft insertion end side. The arrival of the weft end is the weft detector 18.
If it is not detected by, the operation of the loom is stopped. The loom is stopped immediately before beating, and when the loom is stopped, the rotary solenoid 10 is demagnetized.

Demagnetization of the rotary solenoid 10 is maintained until θ = θ ₁ of the next weft inserting cycle. Therefore, when the weft-locking pin 2-1 prevents the weft Y from being pulled out, the weft Y is braked by the braking wire 11. Therefore, the weft Y is not cut by the shock when the pulling out is prevented.

The flight speed of the weft Y, which is inserted by the air injection, varies. When the flying speed of the weft Y is slower than the proper speed, the timing θω (shown in FIG. 3) at which the weft tip reaches a predetermined position at the weft insertion end is delayed from the proper timing. If the flying of the weft Y is braked by the braking wire 11, the weft end arrival timing θω is further delayed. If the weft yarn end arrival timing θω is delayed from the allowable range by braking the flying of the weft Y by the braking wire 11, the risk that the weft Y interferes with the warp yarn going from the open state to the closed state increases. Such interference leads to weft insertion errors.

In this embodiment, the difference Δθn is smaller than the set difference α.
Demagnetization of the rotary solenoid 10, that is, weft
The braking start for Y starts from the detection pull-out timing θx.
K for a certain period₁Will be done later. However, the difference Δθn is
When α or more, the braking start for the weft yarn Y has a difference Δθn
The period K from the detection extraction timing θx according to the size
₁・ Δθn₁Will be done later. In addition, the weft unwinding detection signal Pn
Is the machine rotation angle [θ₂, Θ₃] Did not output in the range
In this case, the braking of the weft Y starts at the time {θ ₃+ K₁
(Θ₃−θn)} for a certain period of time K₂Will be done later.

The larger the delay of the detected pull-out timing θx with respect to the reference pull-out timing θn, the greater the influence of the braking start timing of the braking wire 11 on the delay of the weft yarn tip arrival timing θω. In the present embodiment, the braking start timing θy of the braking wire 11 is delayed in response to the delay Δθn of the detected withdrawal timing θx with respect to the reference withdrawal timing θn increasing in the range of the set difference α or more. Therefore, the influence of the braking action of the braking wire 11 on the delay of the weft yarn tip arrival timing θω is reduced, and the weft insertion state is stabilized. The set difference α and the constant K ₁ are determined so that the delay of the weft yarn tip arrival timing θω is within the allowable range even when the detected drawing timing θx is delayed from the reference drawing timing θn.

The weft unwinding detection signal Pn indicates the machine base rotation angle [θ
_It is most likely that the weft flying speed is quite slow when the output is not within the range [ ₂ , θ ₃ ]. Therefore, in such a case, it is considered that the weft flying speed is considerably slow, and the braking start for the weft Y starts at the time {θ ₃ + K ₁ (θ ₃ −θ
n)} after a certain period of time K ₂ . Also in this case, the influence of the braking action of the braking wire 11 on the delay of the weft yarn tip arrival timing θω is reduced, and the weft insertion state is stabilized. The constant K ₂ is obtained when the weft unwinding detection signal Pn is the machine rotation angle [θ ₂ ,
Even if the output is not made in the range of [θ ₃ ], the delay of the weft yarn tip arrival time θω is determined to be within the allowable range.

By avoiding the delay of the weft yarn tip arrival timing θω by setting the braking start timing as described above, it becomes possible to reduce the set injection pressures of the weft insertion main nozzle 3 and the weft insertion auxiliary nozzle 16. As a result, yarn breakage due to the jetting of the weft inserting main nozzle 3 is eliminated, and the compressed air consumption is also reduced.

Next, the embodiment shown in FIG. 5 will be described. In this embodiment, a weft arrival detector 19 serving as a pull-out timing detecting means is installed within the weaving width. The arrival of the tip of the weft Y flying in the warp shed is detected by the weft arrival detector 19. This arrival detection signal is sent to the comparison difference calculation circuit 5. The other structure is the same as that of the first embodiment. The comparison difference calculation circuit 5 calculates the difference between the output timing θx of the arrival detection signal obtained from the weft arrival detector 19 and the reference drawing timing θn. The braking timing control circuit 6 selects the braking start timing according to the value of the difference Δθn as in the case of the first embodiment. The detection of the arrival of the front end of the weft by the weft arrival detector 19 reflects the magnitude of the flying speed of the weft Y more accurately than in the case of the first embodiment. Therefore, the braking start control by the braking timing control circuit 6 is performed more accurately than in the first embodiment in accordance with the flying state of the weft Y.

As a weft braking device, as shown in FIG. 6, a braking nozzle 23 is mounted in a pipe 22 for supporting the yarn guide rings 20, 21, and the weft Y is bent by the braking nozzle 23 to apply braking. Good. Braking nozzle 2
The valve opening of the rotary valve 24 that controls the supply of pressure air to the valve 3 is controlled by the braking force control circuit 25. The comparison difference calculation circuit 5 calculates the difference between the output timing θx of the weft unwinding detection signal obtained from the weft unwinding detector 4 and the reference drawing timing θn. The braking force control circuit 6 selects the valve opening degree of the rotary valve 24 according to the value of the difference Δθn as in the case of the first embodiment. When the difference Δθn is small, the valve opening degree of the rotary valve 24 is increased, and when the difference Δθn is large, the valve opening degree of the rotary valve 24 is decreased. The smaller the valve opening, the smaller the injection flow rate from the braking nozzle 23, and the smaller the braking force on the weft Y. Therefore, the difference Δ
When θn is large, that is, when the flying speed of the weft Y is low, the braking force on the weft Y is small. As a result, the weft yarn tip arrival timing θω due to the braking injection action of the braking nozzle 23
The influence on the delay of is reduced and the weft insertion state is stabilized.

Further, in the present invention, the braking wire 1 of the first embodiment
The first braking action position, that is, the position of the position regulating body 13 can be changed so as to approach and separate from the other position regulating body 14, and the position of the position regulating body 13 is changed according to the difference Δθn. May be. When the difference Δθn is small, the position regulating body 13 is separated from the position regulating body 14, and the difference Δθn
When n is large, the position regulating body 13 is brought close to the position regulating body 14. The smaller the distance between the two position regulating bodies 13 and 14, the smaller the braking force of the braking wire 11 on the weft Y. In this embodiment, the same effect as that of the embodiment of FIG. 6 can be obtained.

Inventions other than those described in the claims that can be understood from the above-described embodiments will be described below together with their effects. (1) In a jet loom in which the stored wefts in the weft measuring and storing device are injected by the jetting action of the main nozzle for weft insertion, the timing for drawing out a preset withdrawal amount of the wefts drawn from the weft measuring and storing device is withdrawn. The detection withdrawal timing detected by the timing detection means and the detected withdrawal timing detected by the withdrawal timing detection means are compared with the preset reference withdrawal timing by the comparison difference calculation means to give a difference, and the braking force control means responds to the difference. A weft insertion control method in a jet loom for controlling the braking force of the weft braking means. (2) To brake the weft between the weft measuring storage device and the main weft inserting nozzle in a jet loom where the stored weft in the weft measuring storage device is injected by the jet action of the main weft inserting nozzle. The weft braking means, the withdrawal timing detecting means for detecting the withdrawal timing of the preset withdrawal amount of the weft withdrawn from the weft measuring and storing device, and the withdrawal timing detected by the withdrawal timing detecting means. A comparison difference calculating means for comparing the reference drawing timing to obtain a difference and a control for controlling the braking force of the weft braking means according to the difference between the detected drawing timing obtained by the comparison difference calculating means and the reference drawing timing. A weft insertion control device in a jet loom including a power control means.

In both cases (1) and (2), the weft insertion state is stable.

[0031]

As described above in detail, the present invention detects the braking timing for braking the weft between the weft measuring and storing device and the main nozzle for weft insertion based on the difference between the withdrawing timing and the reference withdrawing timing. Therefore, the braking effect that can prevent the yarn breakage can be applied to the weft thread so as to ensure the good weft insertion.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment embodying the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a graph showing the amount of weft pulled out and the braking timing.

FIG. 4 is a flowchart for controlling braking timing.

FIG. 5 is a side sectional view showing another example.

FIG. 6 is a side sectional view showing another example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Weft length measuring storage device, 4 ... Weft unwinding detector which serves as pull-out timing detection means, 5 ... Comparison difference calculation circuit which serves as comparison difference calculation means, 6 ... Braking timing control circuit which serves as braking timing control means, 10 ... A rotary solenoid that constitutes the weft braking means, 11 ... a braking wire that constitutes the weft braking means, 19 ... a weft arrival detector that serves as pull-out timing detection means, 23 ... a braking nozzle that constitutes the weft braking means, 24 ... a weft braking means Comprising rotary valve, Y
... weft.

Claims (2)

[Claims] 1. A drawing timing of a preset withdrawal amount of a weft drawn from a weft measuring and storing device in a jet loom in which the stored weft in the weft measuring and storing device is injected by a jetting action of a main nozzle for weft insertion. Is detected by the withdrawal timing detection means, the detected withdrawal timing detected by the withdrawal timing detection means and a preset reference withdrawal timing are compared with each other by a comparison difference calculating means, and a difference is obtained, and the braking timing control means obtains the difference. A weft-insertion control method in a jet loom for controlling the operation timing of the weft braking means in accordance therewith. 2. In a jet loom in which the stored weft in the weft measuring and storing device is injected by the jetting action of the main nozzle for weft insertion, braking is applied to the weft between the weft measuring and storing device and the main nozzle for weft insertion. Weft braking means for hanging, pull-out timing detection means for detecting the pull-out timing of a preset pull-out amount of the weft drawn out from the weft measuring and storing device, and detection pull-out timing detected by the pull-out timing detection means and preset A comparison difference calculation means for comparing the calculated reference drawing timing to obtain a difference, and controlling the operation timing of the weft braking means according to the difference between the detected drawing timing and the reference drawing timing obtained by the comparison difference calculating means. In a jet loom with braking timing control means Insertion control device.