JPH04241147A - Starting of weaving machine - Google Patents

Abstract

PURPOSE:To effectively prevent defects of woven fabric caused by shrinkage of weft by reversing a weaving machine to remove bad yarn, normally operating a selvage forming device and firmly restricting final weft through selvedge yarn. CONSTITUTION:In restarting a jet loom stopped by weft, a weaving machine is reversely operated, pick finding is carried out to remove bad weft and the weaving machine is normally operated or an auxiliary motor of exclusive use is driven to normally operate a selvedge forming device. By the operation, final weft normally subjected to weft inserting just before stopping of the weaving machine is firmly restricted with upper and lower selvedge yarns in such a way that the final weft crosses the yarns, is sandwiched between the yarns and wound. Consequently even in the case of using strongly shrinkable yarn such as hard twist yarn or spandex, shrinkage of weft apt to occur in setting an opening device in a given starting angle is obstructed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for starting a loom in a jet loom, which effectively prevents fabric defects from occurring due to shrinkage of weft yarns when restarting a loom that has stalled.

0002

2. Description of the Related Art When a highly contractile weft yarn is used in a jet loom, fabric defects may occur due to shrinkage of the weft yarn when the weft is restarted after the weft has come to rest.

[0003] In order to remove the defective weft yarn that caused the weft to stall, the loom first performs one rotation of reverse operation after stopping, thereby releasing the defective weft yarn from being restrained by the warp (so-called reverse start-up). motion). Therefore, after removing the defective weft yarns, the loom is reversed about one rotation, the loom is set at a predetermined starting angle, and then starting from this starting angle is performed. At this time, the first reed beating after startup is performed without weft insertion, so-called dry beating, and the second and subsequent reed beatings are actual reed beating. This starting method is widely known as a dry start, and according to this method, the first reed beating, which tends to lack the reeding force, is a blank beating, so it is effective for the generation of weaving steps. can be prevented.

However, when such a starting method is used, the warp shedding opens when the reverse operation is completed after removing the defective weft, and the weft that was normally inserted just before the loom stops (hereinafter referred to as the final weft) is , the binding force of the warp yarns is lost, so the final weft yarns may shrink and create new fabric defects. This type of fabric defect is particularly noticeable when using highly shrinkable weft yarns such as high twist yarns or spandex yarns.

[0005] Therefore, as a countermeasure to this problem, a technique using an ear-closing device is known (Japanese Unexamined Patent Publication No. 62-2
06059). This device temporarily disconnects the selvage tying device from the main shaft when performing a reverse operation after removing defective weft yarns, or even if the selvedge tying device reverses in conjunction with the main shaft.
In order to prevent the influence from reaching the binding point of the weft yarn by the selvage yarn,
By introducing a kind of twist stopping device, the final weft is kept restrained by the selvedge yarn, and its shrinkage is prevented.

[0006]

Problems to be Solved by the Invention With such conventional techniques, there is a problem in that it is not always possible to sufficiently prevent the shrinkage of the weft yarns, and it is difficult to completely prevent the occurrence of fabric defects. In other words, the final weft at this time is restrained by the upper selvage thread and the lower selvage thread crossing once between the reed and the woven fabric, but the position of this crossing point is Because the distance from the selvage device to the selvage device is long, it tends to be far away from the fabric. Therefore, the restraining force obtained is only weak, and it is difficult to strongly hold highly twisted yarns, spandex yarns, etc. against the tension.

Therefore, in view of the actual state of the prior art, an object of the present invention is to remove defective weft yarns and then actively rotate the selvage device in the normal direction, so that the weft yarns are strongly twisted yarns, spandex yarns, etc. Another object of the present invention is to provide a method for starting a loom that can generate a binding force that can hold the weft in a sufficiently stable manner and can effectively prevent fabric defects from occurring due to shrinkage of the weft.

[0008]

[Means for Solving the Problems] The configuration of the present invention for achieving the above object is such that when restarting a loom that has stopped weft, the loom is reversed to remove defective weft yarns, and then the selvage tying device is rotated in the normal direction. At the same time, the shedding device and the reed are set at a predetermined starting angle, and the loom is started.

[0009] The selvage assembly device may be rotated in the normal direction by rotating the loom in the normal direction, or may be rotated in the normal direction by a dedicated auxiliary motor.

0010

[Operation] With this configuration, the selvage assembly device is always driven in normal rotation when setting the shedding device and the reed to a predetermined starting angle after removing a defective weft yarn. By rotating the selvage device in the normal direction, the upper and lower selvage threads do not simply intertwine, but can be twisted so as to sandwich the final weft thread, which exerts a strong binding force on the final weft thread. It can be prevented from shrinking.

[0011] The timing for normal rotation of the ear assembly device is determined by the opening device,
When driving the reed to a predetermined starting angle, it is not necessary to drive the reed later than the time when the warp shedding opens, and it is also possible to drive the reed earlier than this.
It may be done at the same time. Note that, for the shedding device, the predetermined starting angle here corresponds to the loom cycle (hereinafter referred to as the starting cycle) that is one cycle before the loom cycle in which the weft insertion defect occurred (hereinafter referred to as the defect occurrence cycle). This refers to the crank angle at which the loom starts in the shedding pattern, and for reeds, it refers to the crank angle that corresponds to the starting angle of the shedding device.

[0012] If the selvage assembly device is rotated in the normal direction by rotating the loom in the normal direction, no special mechanical device is required.
This invention can be implemented. However, in this case, instead of the reverse operation after removing the defective weft yarn, a forward rotation operation will be performed, so if the shedding pattern is plain weave, one rotation of forward rotation is sufficient, but one cycle of n cycles is sufficient. In the case of a complicated weaving pattern, it is necessary to perform (n-1) normal rotations and set the starting angle of the shedding device. In any case, the position of the weaving cloth is properly corrected using a well-known cloth cloth position correcting means before starting, thereby preventing the occurrence of weaving steps.

When the selvage-assembling device is rotated forward by a dedicated auxiliary motor, the shedding device and the reed can be driven independently of the selvedge-assembly device, so the loom can be rotated in reverse, forward, or in other ways. Both may be driven simultaneously or independently by any dedicated auxiliary motor.

[0014]

[Embodiment] An embodiment will be explained below with reference to the drawings.

The method for starting a loom can be carried out in a known air jet loom or water jet (FIG. 1).

[0016] The warp threads P, P... are the reed feathers R1, R1 of the reed R.
... and is opened according to a predetermined opening pattern by a heald frame (not shown). The weft yarn F is inserted through the nozzle NZ and driven into the fabric front Wa by the reed R, thereby weaving the woven fabric W. The inserted weft yarn F is cut by the yarn feeding cutter CT1 every pick. Additionally, selvage threads S, S supplied from the selvage assembly device SV run on the outside of the warp threads P, P..., which capture the surplus portion of the inserted weft thread F to create a waste selvage SG. Can be done. However, the surplus portion of the weft F is cut by a waste edge cutter CT2 after multiple picks after weft insertion, and is separated from the woven fabric W, and the waste edge SG is
It is gripped by take-up rollers RL, RL, taken off at the same speed as the woven fabric W, and discarded (FIG. 2).

[0017] The ear assembly device SV is, for example,
This is well known from Japanese Patent No. 2835. Ear assembly device S
V is the bobbin S1, S1 which is the supply source of the selvage thread S, S
are held, and the bobbins S1 and S1 are each
By driving the sun gear G1, the planetary gear G2
, through the relay gear G3, it can rotate while revolving around the sun gear G1, and the selvage yarns S, S can be let out from the tips of the yarn guides Y, Y. However, at this time, the tips of the yarn guides Y, Y draw a spindle-shaped locus x with a small bulge in the vertical direction, and therefore the selvage yarns S, S can be twisted by opening up and down. Therefore, bobbin S1
, S1 are synchronized with the rotation of the main shaft of the loom, the selvage threads S, S can be captured by twisting the weft threads F, F, . . . in sequence.

Now, when the loom is operating normally, if a weft insertion failure occurs in the loom cycle Ko (FIG. 3), the loom will restart after inertia operation in response to a stop signal from a weft feeler (not shown). Next loom cycle K1
It stops in the open state at . At this time, the warp P, P
..., the selvage yarns S and S include the defective weft Fb, and the final weft Fb
a, all the previous normal wefts F, F, etc. are restrained (Fig. 4(a), (b)). However, the opening pattern at this time is a simple plain weave with two cycles as one period (FIG. 3).

Thereafter, the loom performs a reverse pick-up operation in response to the pick-up command, and picks out the defective weft Fb. As a result, the reed R, the opening device (not shown), the ear assembly device SV
are interlocked and reversed, so warp threads P, P..., selvage threads S, S
releases the restraint of the defective weft Fb (Fig. 5(a), (
b)). Therefore, the defective weft Fb is removed.

[0020] Next, the loom performs a normal rotation operation of about one rotation in response to a normal rotation command (FIG. 3), rotates the selvedge device SV in the normal direction, and sets the reed R and the shedding device to the starting angle. As a result, the warp threads P, P... are opened in a shedding pattern that matches the shedding pattern of starting cycle K-1.
However, the restraint on the final weft Fa is released (Fig. 6
(A)), the selvage yarns S and S are twisted once in front of the final weft Fa because the selvage assembly device SV rotates in the normal direction ((b) in the same figure), and the selvage threads S and S are twisted once in front of the final weft Fa (Fig. It is possible to express a strong binding force.

[0021] Thereafter, the loom returns to normal operation after one dry run in response to a start signal (FIG. 3). At this time,
Since the shedding pattern in the loom cycle K2 in which the first actual beating is performed is the same as that in the defect generation cycle Ko, the woven fabric W can continue a continuous weaving pattern before and after the weft insertion defect. can.

In the above description, the selvage assembly device SV can be disposed not only on the weft insertion side of the woven fabric W but also on the opposite weft insertion side. At this time, both ear assembly devices SV, SV are
It is enough to do the same action. In addition, when the position of the loom Wa moves due to the reverse start-up operation and the subsequent normal rotation operation, when the loom Wa is moved by a well-known loom position correction means for driving and adjusting the unillustrated feeding device and winding device, What is necessary is to optimally adjust the position of the woven fabric Wa.

[0023]

[Other Examples] If the shedding pattern is not a plain weave but a complex weave pattern with n cycles as one period, the normal rotation of the loom after removing the defective weft Fb is approximately (n
-1) Rotation can be used (Figure 7). However, here:
It is assumed that when n=6, a weft insertion failure occurs in the fourth cycle. The shedding pattern in the loom cycle K6, in which the first actual beating after starting the loom is performed, can be made to match that in the failure occurrence cycle Ko by performing approximately (n-1)=5 forward rotations. In this case, since the selvage assembly device SV also performs about 5 rotations in the normal direction, the selvage threads S, S are connected to the final weft thread F.
It will be twisted 5 times in front of a, and the final weft Fa
It is possible to provide a stronger binding force to the

The ear assembly device SV can be connected to the main shaft AX via a clutch CL (FIG. 8). The main axis AX is
Driven by the main motor M, the shedding device PS and the reed R are
It is connected to the main shaft AX.

After the main motor M rotates the loom in the reverse direction after stopping the weft (FIG. 9) and removes the defective weft Fb,
The main motor M rotates the loom one rotation forward, and the selvedge device SV
is rotated in the normal direction, and the final weft Fa is restrained by the selvedge threads S and S. Thereafter, the clutch CL is disconnected, the loom is reversely rotated approximately two times by the main motor M, and then the clutch CL is reconnected. Subsequently, by starting the loom, the first actual beating after starting can be made to coincide with the failure occurrence cycle Ko.

In this case, the number of normal rotations of the selvedge device SV due to the normal rotation of the loom may be a rotation (a is any integer satisfying a≧1). This is because if the number of subsequent reversals of the loom is (a+1) rotations, the predetermined shedding pattern i can be reproduced.

The shedding device PS may be connected to the main shaft AX via a clutch CL (FIG. 10) and driven independently by a dedicated auxiliary motor Mp. The ear assembly device SV is connected to the main shaft AX together with the reed R, and is driven by a main motor M.

At this time, after the loom is stopped and the defective weft Fb is removed by a reverse pick-up operation (FIG. 11), the loom is rotated in the forward direction by the main motor M about one rotation, and the selvedge device SV is rotated in the forward direction. The final weft Fa is restrained by the selvage yarns S and S. After that, the clutch CL is disconnected, and the auxiliary motor Mp
By reversing only the shedding device PS twice, the shedding pattern i is delayed by two cycles. As a result, the loom cycle K2 in which the first actual beating after startup is performed.
Since the opening pattern i in the clutch C can be matched with that in the failure cycle Ko,
Just reconnect L and start the loom.

In this case, the number of normal rotations of the ear assembly device SV can also be set to approximately a (a≧1) rotations, and by making the subsequent reversal of only the shedding device PS to be (a+1) rotations, a predetermined number of rotations can be achieved. can reproduce the aperture pattern of

The selvedge device SV may be connected to the main shaft AX via a clutch CL (FIG. 12) and driven independently by an auxiliary motor Ms.

After removing the defective weft Fb, the clutch C
At the same time as cutting L (FIG. 13), the main motor M reverses the loom including the shedding device PS and the reed R. At the same time, only the selvage assembly device SV is rotated forward by the auxiliary motor Ms, and the final weft Fa is restrained by the selvage threads S and S. after that,
All you have to do is connect the clutch CL and start the loom. The selvage assembly device SV can perform forward rotation an arbitrary number of times more than one rotation, and the drive start point is set before the final weft Fa is released from being restrained by the warp threads P, P, etc. due to the reversal of the loom. It can be arbitrarily determined as long as the weft Fa can be restrained.

In this embodiment, since the selvedge assembly device SV is independently rotated in the normal direction by the auxiliary motor Ms, the setting of the starting angle of the shedding device PS and the reed R by the main motor M is as shown in FIG.
This can also be done by rotating the loom in the normal direction as shown in FIG. Also, following FIGS. 10 and 11, the opening device P
It is also possible to use a dedicated auxiliary motor Mp for S.

[0033] Furthermore, the present invention also applies when the selvage assembly device SV forms the selvage tissue of the woven fabric W instead of the discarded selvage SG.
It can be applied as is.

[0034]

[Effects of the Invention] As explained above, according to the present invention, after the loom is reversed to remove defective weft yarns, the selvage tying device is rotated in the normal direction, thereby strongly restraining the final weft yarns via the selvage yarns. Even if the weft is a strongly shrinkable yarn such as a highly twisted yarn or a spandex yarn, the weft is reliably prevented from shrinking when the shedding device is set at a predetermined starting angle. Therefore, there is an excellent effect that fabric defects caused by shrinkage of the weft yarns can be effectively prevented.

[Brief explanation of the drawing]

[Figure 1] Planar diagram of the main parts of the loom

[Figure 2] Side view of the ear assembly device

[Figure 3] Diagram explaining overall operation

[Figure 4] State diagram of warp and selvage threads when weft stops

[Figure 5
] State diagram of warp and selvage threads when reverse start-up is completed

[Figure 6]
State diagram of warp and selvage threads when set at starting angle

[Figure 7]
A diagram corresponding to FIG. 3 of other embodiments

[Figure 8] Schematic diagram of the main parts of a loom according to another embodiment

[Figure 9
] A diagram corresponding to FIG. 3 of another embodiment

[Figure 10] A diagram equivalent to Figure 8 of yet another embodiment

[Figure 11
】 A diagram corresponding to FIG. 3 of yet another embodiment

[Fig. 12] A diagram corresponding to Fig. 8 of yet another embodiment

[Fig. 13] A diagram corresponding to Fig. 3 of yet another embodiment

[Explanation of symbols]

Fb...Defective weft SV...Ear assembly device PS…Opening device R…Reed Ms...Auxiliary motor

Claims (3)

[Claims] [Claim 1] When restarting a loom that has stopped weft,
A method for starting a loom, which comprises: reversing the loom to remove defective weft yarns, then rotating a selvage device in the normal direction, setting a shedding device and a reed at a predetermined starting angle, and starting the loom. 2. The method for starting a loom according to claim 1, wherein the selvedge device rotates in the normal direction by rotating the loom in the normal direction. 3. The method for starting a loom according to claim 1, wherein the selvage device is rotated in the forward direction by a dedicated auxiliary motor.