JPH0735624B2 - Weft insertion device for loom using moving magnetic field - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a weft inserting device for a loom using a moving magnetic field, and more specifically, a flying body such as a gripper or a shuttle using a moving magnetic field (linear motor). The present invention relates to a weft inserting device of a type in which wefts are inserted to perform weft insertion.

(Prior Art) Recently, even in the loom of a type in which a flying object such as a gripper or a shuttle is flying to perform weft insertion, from the viewpoint of enabling high-speed operation and reducing noise during operation, FIG. A linear motor type as shown in FIG. 1, that is, a moving magnetic field A is provided continuously in the weft insertion direction in the sley 1 or in a part of the sley, and a gripper 70 or shuttle made of, for example, a lightweight metal material is flown over this. Many weaving machines of the type in which weft insertion is performed by running them have been proposed.

(Problems to be Solved by the Invention) Generally, it is well known that in order to perform high-speed weft insertion using a moving magnetic field, it is necessary to strongly excite the magnetic field and increase the frequency.

However, when the magnetic field is strongly excited, heat generation in the moving magnetic field increases, which not only shortens the life of the coil but is also not preferable from the viewpoint of energy saving.

By the way, in a conventional linear motor type weft inserting device of a type in which a moving magnetic field is provided continuously over the entire weft inserting direction of the sley or in a part of the sley, excitation of the moving magnetic field is partially performed. It could not be controlled, and there was no choice but to perform uniform excitation in the entire extension direction. Therefore, if the magnetic field is constantly excited, the loss of electric energy is extremely large, and if the coil is damaged due to long-term heat generation, the entire coil must be replaced, which also reduces maintenance costs. Not good.

However, it is not necessary to perform uniform excitation as a whole as described above. For example, it is possible to apply proper tension to the weft yarn by exciting at a lower frequency in the vicinity of both ends than in the vicinity of the center.

Therefore, an object of the present invention is to optimize the flight mode of a flying object in accordance with a wide variety of changes according to the weft insertion pattern over the entire width of the cloth.

(Means for Solving the Problems) Therefore, in the present invention, the moving magnetic field is divided into a plurality in the weft inserting direction, and each moving magnetic field is excited by the timing controller only at a preset timing, and The frequency for exciting each moving magnetic field is individually set according to the weft insertion pattern by the frequency controller.

In the following description, a gripper is used, but this is for convenience and needless to say, a shuttle type may be used.

(Example) Hereinafter, the Example of this invention is described.

As shown in FIG. 1, a moving magnetic field A is provided in a divided manner in a flying direction of the gripper 70 in a sley (not shown). The moving magnetic fields A _{1 to} A ₅ are connected to the corresponding inverters B _{1 to} B ₅ , respectively. These inverters B ₁
~ B ₅ are weft insertion timing controller 5 and frequency controller 7 respectively
The weft-insertion timing controller 5 is connected to an encoder 15 and a timing setter 16 mounted on the crankshaft of a loom (not shown). Frequency controller 7
Is connected to a frequency setter 27 and a tachogenerator 17, which is installed as a loom rotation detector, so that the moving speed (frequency) of the moving magnetic field can be set according to the weft insertion pattern and the loom rotation speed. The command signal corresponding to is emitted.

As shown in FIG. 3, the frequencies of the moving magnetic fields A _{1 to} A ₅ are set so that the moving magnetic field A ₁ located on the yarn feeding side is set to a low frequency in order to accelerate the gripper 70, and the moving magnetic field A _{3 at the} center of the sley is set. The frequency is set higher as you go to, and the flying gripper 70 goes from the center to the moving magnetic field A ₅ on the anti-feeding side.
The frequency is set to be gradually weakened in order to decelerate.

The length dimension in the weft inserting direction of each of the above divided moving magnetic fields is such that when the central moving magnetic field A ₃ whose frequency is set high is set longer than the moving magnetic fields A ₁ and A ₅ on both ends, the gripper 70 is set. High speed running is possible and weaving efficiency is improved.

Further, in the example shown in FIG. 3, the respective excitation frequencies are set to be almost equal in height difference over the same period, but the present invention is not limited to this. The period of each excitation frequency can be freely set to be short or long. Further, the height difference is not limited to the example shown in the figure, and can be set to any size.

If a gripper 70 or shuttle that uses a conductor is used, slippage occurs. To prevent this, a gripper 70 or shuttle that uses a magnet may be used.

(Operation of the Invention) When the signal from the encoder 15 and the signal indicating the angle set by the timing setting device 16 are input to the weft insertion timing controller, as shown in FIG. 3 through the inverters B _{1 to} B ₅ . Currents are sequentially applied to the corresponding moving magnetic fields A _{1 to} A ₅ at the timings set respectively. Then, the excitation of the moving magnetic field at the portion where the gripper has passed is released.

On the other hand, the signal output from the tachogenerator 17 and the frequency setter 27
Each inverter B ₁ of the frequency controller 7 in the input a signal indicating the set frequency corresponding to the command signal so as to set in accordance with the movement speed of the moving magnetic field A ₁ to A ₅ in the weft insertion pattern
To output toward the ~B _5. The frequency controller 7 corrects the set frequency in proportion to the loom rotation speed by a signal from the tachogenerator 17. Therefore, stable weft insertion can be performed. Then, the gripper 70 grips the weft W from the yarn supplying body 80 and moves according to the movement of the moving magnetic fields A _{1 to} A ₅ .
Needless to say, the weft insertion timing is performed in synchronization with the warp opening while the warp opening is being performed.

In the above embodiment, the set frequency is corrected in proportion to the loom rotational speed. However, if the fluctuation of the rotational speed during stable operation is negligible, in addition to setting the frequency for steady operation, the loom It is also possible to set the frequencies for the transient state of startup and switch them at the time when the steady rotation speed is reached from the signal of the tachogenerator, or after a predetermined time has elapsed after the startup, or at a predetermined timing.

(Effect of the Invention) According to the present invention, the moving magnetic field is divided into a plurality of groups to excite the moving magnetic field of the portion corresponding to the flying position of the gripper, that is, the moving magnetic field of only the excitation required portion. Unlike the conventional one, it is not necessary to constantly apply a high current to the entire moving magnetic field, which is preferable from the viewpoint of power saving.

Further, by dividing the moving magnetic field into a plurality of pieces in the weft inserting direction, it is possible to apply the velocity at different points over the entire width of the cloth.
Further, by exciting each moving magnetic field only at a preset timing, it is possible to apply the velocity in different periods. Furthermore, by individually setting the frequency for exciting each moving magnetic field according to the weft insertion pattern,
Velocity can be applied at different heights. As a result, it is possible to provide the flying object with an optimum flying mode that is rich in various kinds of weft insertion patterns. As a result, the weaving efficiency in which the flying speed of the gripper is increased is significantly improved, and an appropriate tension can be applied to the weft yarn during weft insertion, so that the fabric quality can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a weft inserting device of a loom according to the present invention. FIG. 2 is an explanatory view showing an apparatus to which the principle of the linear motor type weft inserting method is applied. FIG. 3 is a graph showing an example of timings and levels of frequencies applied to each moving magnetic field of the present invention. 1 ... Sley, 5 ... Weft insertion timing controller 7 ... Frequency controller, 15 ... Encoder 16 ... Timing setting device, 17 ... Tachogenerator 27 ... Frequency setting device, 70 ... Gripper 80 ... Yarn feeder, 90 ... Yarn guide W ... Weft, A, A ₁ ~ A ₅ ... Moving magnetic field B ₁ ~ B ₅ ... Inverter

Claims (3)

[Claims] 1. A type in which a moving magnetic field is formed so as to extend in the weft inserting direction, and weft insertion is performed by flying a flying object on the moving magnetic field. The moving magnetic field is divided into a plurality of parts in the weft inserting direction. And a frequency controller for exciting each moving magnetic field only at a preset timing and a frequency controller for individually setting the frequency for exciting each moving magnetic field according to the weft insertion pattern. A weft inserting device for a loom using a characteristic moving magnetic field. 2. The frequencies for exciting the respective moving magnetic fields are set so as to increase from those located at both ends in the weft inserting direction toward the central portion. The device according to paragraph. 3. The moving magnetic field divided into a plurality of pieces, wherein the one located at the central portion has a division length set to be larger than the other ones. The apparatus according to item 2.