JPH0545706B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention provides a means for measuring and storing weft yarns and for measuring and storing the length of weft yarns through the engagement and disengagement between a yarn winding surface forming body for winding weft yarns and a weft locking body. The present invention relates to a weft length measuring method in a jet room using a weft length measuring and storage device that controls withdrawal from a weft.

(Prior art) As this type of weft length measuring and storage device,
In the conventional device disclosed in Japanese Patent No. 29640, a thread winding tube for winding and supplying a weft around a drum-shaped thread winding surface forming body is driven by a motor separate from the machine drive motor, and a weft thread locking body is driven by an electromagnetic solenoid, and the weft locking operation of the weft locking body is controlled by a photoelectric yarn unwinding detection means. By adopting such a control method, it is possible to easily change the timing at which the weft yarn is stopped being pulled out from the yarn winding surface, which leads to a change in the weft length measurement amount.
Furthermore, excessive length measurement can be avoided during irregular operations such as when the machine is started up at a speed lower than the machine rotational speed during normal operation, or during machine inching operation. However, since the yarn unwinding detection means is constantly operating,
Counting errors are likely to occur due to the detection of fluff, and there is a problem of insufficient length measurement due to the detection of fluff, as opposed to excessive length measurement.

A length measurement storage device that attempts to solve this problem is disclosed in Japanese Utility Model Application Publication No. 106976/1983. In this device, a period during which a predetermined unwinding of the winding yarn is expected to be detected is set in advance, and when the detection timing of the predetermined unwinding of the winding yarn is within the set expected detection period, this predicted detection is performed. An ejection command for the weft locking body is issued at the timing, and if the expected detection timing of the predetermined yarn unwinding is not within the set period, the ejection command is issued at the time of the previous weft locking body ejection command time. . As a result, even if air fluff is detected, the weft locking body protrusion command is performed after unwinding the number of yarns corresponding to the set weft insertion length, eliminating the lack of length measurement caused by air fluff detection. be done.

(Problem to be Solved by the Invention) However, since the detection period set as the predetermined unwinding prediction detection period is fixed,
Variations in the winding yarn unwinding timing subsequent to the final winding yarn unwinding due to variations in the machine rotation speed, fluctuations in the weft injection speed, or changes in the diameter of the weft cheese are related to the fixed expected detection period. In some cases, the unwinding prevention timing range specified by the above may be exceeded. Therefore, even after the final unwinding, one turn of the winding thread is unwound and inserted into the weft, and the unnecessarily long discarded selvage part gets into the warp opening and is woven into the woven fabric. This may cause fabric defects. A possible solution to this problem is to correct the injection pressure of the weft insertion fluid, but it is quite difficult to automatically correct the injection pressure while the loom is operating in accordance with the actual unwinding situation. Accompany.

Structure of the Invention (Means for Solving the Problems) Therefore, in the present invention, a predetermined number of times the thread is unwound from the thread winding surface is set, and the thread being pulled out and unwound from the thread winding surface is pulled out and unwound. setting a winding thread unwinding prediction detection period including a reference time and a synchronous quasi-time defining the unwinding prevention command time to prevent the unwinding;
If the set predetermined unwinding of the thread is not detected within the set winding release prediction detection period, an unwinding prevention command is issued at a time specified in relation to the set reference time, and the set The reference period and the set yarn unwinding prediction detection period are maintained, and if only the set predetermined winding yarn unwinding is detected within the set yarn unwinding prediction detection period, this winding yarn unwinding is performed. The unwinding prevention command is issued at a time specified in relation to the detection time, and the set reference time and the set expected winding thread unwinding detection period are corrected in relation to the same winding thread unwinding detection time. .

(Operation) That is, if the predetermined unwinding of the winding thread is not detected within the set winding thread unwinding prediction detection period and the number of winding thread unwinding detections has already reached the predetermined number, the above-mentioned The unwinding prevention operation of the weft yarn locking body is delayed from the set reference time by a time defined in relation to the set reference time, for example, the expected interval period between the predetermined unwinding and the final unwinding. is commanded, and the set reference time and the set yarn unwinding prediction detection period are maintained as they are. If a predetermined unwinding of the winding yarn is detected within the set winding yarn unwinding prediction detection period, a time specified in relation to this winding yarn unwinding prediction detection time;
For example, the unwinding prevention operation of the weft thread locking body is commanded after the expected detection timing of the predetermined thread unwinding by the expected interval period between the predetermined thread unwinding and the final winding thread unwinding, and The reference timing and the set winding yarn unwinding prediction detection period are corrected in relation to the predetermined actual winding yarn unwinding detection timing.

(Example) Hereinafter, an example embodying the present invention will be described based on the drawings.

A rotary support tube 3 is rotatably inserted through an annular bracket 2 fixed to a side frame 1 of the loom, and a weft yarn Y supplied from a cheese 4 is introduced thereinto. A thread-wrapped tube 5 is attached to the rotational support tube 3 so as to communicate with the rotational support tube 3, and its tip is opened near a thread-wrapped surface, which will be described later.
A drum-shaped thread wrapping surface forming member 6 is supported at the tip of the rotation support tube 3 so as to be relatively rotatable, and a gear 7 fixed to the annular bracket 2 and the thread wrapping surface forming member 6 are fixedly attached. The gear 8 is meshed and connected by planetary gears 9 and 10. Due to this meshing relationship, even when the rotating support tube 3 side rotates, the thread-wrapped surface forming body 6
The side is held stationary without rotating, and the weft Y supplied from the thread wrapping tube 5 is attached to the thread wrapping surface forming body 6.
The thread is wound around the thread winding surface 6a of the thread winding surface 6a.

The rotation support tube 3 is rotated by a motor 11 that is separate from the machine drive motor (not shown), and the operation of the motor 11 is controlled by a control computer C.
Controlled by instructions from.

A phototube 12 is disposed near the thread winding surface 6a of the thread winding surface forming body 6, and a weft locking body 14 driven by an electromagnetic solenoid 13 can intersect with and separate from the thread winding surface 6a on the front side thereof. It is arranged. The phototube 12 sends a signal current corresponding to the amount of light reflected from the thread winding surface 6a to the control computer C via the signal shaping circuit 15.
The operation of the motor 11 is controlled in accordance with this signal, and the rotation of the motor 11 is controlled so that the amount of yarn stored is equal to or greater than a predetermined amount. Further, the control computer C controls the excitation and demagnetization of the electromagnetic solenoid 13 via the drive circuit 16, and the demagnetization of the electromagnetic solenoid 13 causes the weft locking body 14 to intersect with the thread winding surface 6a, causing the electromagnetic solenoid 13 to intersect with the thread winding surface 6a. The weft locking body 14 is separated from the yarn winding surface 6a by the excitation. Weft locking body 1
A weft detector 17 for detecting yarn unwinding is installed near the yarn winding surface 6a with an angular phase difference of 4 to 180 degrees, and the weft release detection signal from the weft detector 17 is sent to a signal shaping circuit 18. The data is taken into the control computer C via.

The control computer C defines the excitation command angle X of the electromagnetic solenoid 13, the reference angle position θ for defining the expected detection angle range for winding yarn unwinding, the demagnetization command angle of the electromagnetic solenoid 13, and the predictive detection angle range for winding yarn unwinding. An angle α for defining the demagnetization command angle of the electromagnetic solenoid 13, an angle β for defining the demagnetization command angle of the electromagnetic solenoid 13, and a predetermined number of unwinding times (n-1) are input and set in advance by the input setting device 19. n is the number of windings corresponding to the weft yarn length, and is 4 in this embodiment. The reference angle position θ is corrected as needed based on the yarn unwinding detection information for each weft insertion, and the expected yarn unwinding detection angle range is adjusted based on the reference angle that is corrected as necessary. θ−α, θ+α]. Then, the control computer C calculates and grasps the machine rotation angle based on the machine rotation angle detection signal from the rotary encoder 20, and determines the winding yarn within the set winding yarn unwinding expected detection angle range [θ-α, θ+α]. Demagnetization of the electromagnetic solenoid 13 and correction of the reference angular position θ are controlled based on the unwinding information.

FIG. 3 shows a control flowchart of the control computer C, and the control method will be explained below according to this flowchart.

As shown in FIG. 1, the electromagnetic solenoid 13 is in a demagnetized state and the weft locking body 14 intersects with the thread winding surface 6a, thereby preventing the thread from unwinding on the thread winding surface 6a. When the machine rotation angle position reaches X, the control computer C sends an excitation command to the electromagnetic solenoid 13, and the electromagnetic solenoid 13 is excited. As a result, the weft thread locking body 14 is moved slightly behind the thread winding surface 6.
The thread on the thread winding surface 6a is pulled out from the thread winding surface 6a and unwound by the jet from the main weft insertion nozzle 21. Predetermined (n-1) (=3)
If the detected angle position θ' of the unwinding yarn is within the set expected detection angle range [θ−α, θ+α], the control computer C adjusts the set reference angle position θ to a predetermined value ( The n-1)th unwinding detection angle position θ' is corrected, and the set expected detection angle range [θ-α, θ+α] is changed to [θ′-α, θ′+α].
The degaussing command is issued after the machine rotation angle β has passed from the predetermined (n-1)th unwinding detection angle position.
As a result, after the n-th unwinding, the weft locking body 14
intersects with the bobbin winding surface 6a and prevents the bobbin winding from unwinding.
Therefore, the length of the weft Y ejected from the weft insertion main nozzle 21 is equal to n turns of the winding yarn, and a predetermined length of weft yarn is inserted.

If the predetermined (n-1)th unwinding detection angle position is not included in the set expected detection angle range [θ-α, θ+α], the control computer C calculates the machine rotation angle from the set reference angle position θ. Issue a demagnetization command after β. As a result, for example, fluff is detected as shown by the detection signal D in Fig. 2b, and it is assumed that unwinding is detected n times (=4) within the set expected detection angle range [θ-α, θ+α]. Even when the weft locking body 14
The yarn unwinding prevention operation is performed at an angular position after an angle β from the set reference angular position θ, at which the yarn can be unwound.
The weft insertion length is equal to n turns of yarn. Or, for some reason, the predetermined (n-
1) Even if the second unwinding detection is not performed,
The unwinding prevention operation of the weft thread locking body 14 is performed at an angular position after an angle β from the set reference angular position θ, at which the winding thread can be unwound. The insertion length is n turns of yarn. If yarn unwinding is not actually performed due to a supply error such as yarn breakage or yarn entanglement, the machine is stopped when the error is detected by a weft insertion error detector or a supply error detector (not shown).

The correction from the set reference angular position θ to the actual yarn unwinding detection angle position θ' is performed after the final, ie, nth, unwinding due to variations in machine rotational speed or weft insertion injection speed. This is a countermeasure in line with the fluctuation trend of the winding yarn unwinding time, and in addition to this countermeasure, the setting expected detection angle range [θ-α, θ
+α] to [θ'-α, θ'+α] is based on the tendency of fluctuations in the predetermined (n-1)th unwinding timing due to variations in machine rotational speed or variations in weft insertion injection speed. This is an appropriate response. That is, the fluctuation tendency of the winding yarn unwinding during subsequent weft insertion is a predetermined (n-
1) It is incorporated into the correction of the detected angular position of the yarn unwinding for the th time and the expected detection angle range that includes this detected angular position. Subsequent unwinding of the winding yarn is accurately prevented.

The present invention is, of course, not limited to the above-mentioned embodiments. For example, the reference angular position θ is set for the expected n-th unwinding time, and the demagnetization command limit angular position of the electromagnetic solenoid 13 ( The angular position that cannot be delayed any further) is the reference angular position θ, and the expected detection angle range is [θ-
α, θ], or the reference angular position may be corrected based on the average value or corrected average value of the past several times.

Effects of the Invention As described in detail above, the present invention sets the number of times the winding yarn is unwound and also sets the winding yarn unwinding prediction detection period based on the set reference period, and If the predetermined unwinding of the thread is not detected within the detection period, a thread unwinding prevention command is issued at the reference time, and if the predetermined unwinding of the thread is detected within the set winding thread unwinding prediction detection period. If the above-mentioned reference period and expected detection period of yarn unwinding are corrected, the fluctuation trend of yarn unwinding during weft insertion is determined based on the predetermined yarn unwinding detection period and the winding that includes this detection period. Since it has been incorporated into the correction of the expected detection range for yarn unwinding, even when an abnormality occurs in the detection device, not to mention the detection of fluff, it is possible to unwind yarn with high accuracy by following the operating conditions of the loom. This has an excellent effect of being able to cover variations in the number of threads and accurately preventing unwinding of the yarn after weft insertion of a predetermined length has been completed.

[Brief explanation of the drawing]

1 to 3 show an embodiment embodying the present invention, FIG. 1 is a combination diagram of a weft length measuring and storage device and a block circuit, and FIGS. 2 a, b, and c are all for unwinding. A graph showing the state and the unwinding prevention state;
FIG. 3 is a control flowchart. Yarn winding surface forming body...6, Yarn winding surface...6a, Electromagnetic solenoid...13, Weft locking body...14, Weft detector for detecting yarn unwinding...17, Control computer...C, Reference angular position as reference time...θ, θ', angle...α, β, weft...Y.

Claims (1)

[Claims] 1. In a weft length measurement and storage device that controls length measurement storage and withdrawal of the weft from the thread winding surface by engagement and disengagement between a thread winding surface forming body for winding the weft and an electromagnetically driven weft locking body, the weft A reference time and a synchronized quasi-time for setting a predetermined number of unwinding times from the thread winding surface and specifying an unwinding prevention command timing for preventing the thread from being pulled out and unwound while being pulled out from the thread winding surface. A winding yarn unwinding prediction detection period including the above-mentioned winding yarn unwinding prediction detection period is set, and if the set predetermined winding yarn unwinding is not detected within the set winding yarn unwinding prediction detection period, a prescribed winding yarn unwinding period is specified in relation to the setting standard time. The unwinding prevention command is issued at the specified time, the set standard time and the set winding yarn unwinding prediction detection period are maintained, and the predetermined winding yarn unwinding is performed within the set winding yarn unwinding prediction detection period. If only the thread unwinding is detected, an unwinding prevention command is issued at a time specified in relation to this winding thread unwinding detection time, and at the same time, the above-mentioned set reference time and the above-mentioned A weft length measurement method in a jet room for correcting a set winding yarn unwinding prediction detection period.