JPH07258941A - Driving apparatus for automatic loom - Google Patents

Abstract

PURPOSE:To enable the quick start, quick stop and accurate inching motion of an automatic loom. CONSTITUTION:A main driving shaft 4 of an automatic loom is connected to a motor 16 and provided with a non-excitation working permanent magnet brake 8 to keep the braking state by the attracting force of a permanent magnet 12 and releasing the brake by the repulsion force of an electromagnet 14. A reverse voltage is applied to the electromagnet 14 in the case of starting the main driving shaft 4 to cause the invert excitation of the permanent magnet brake 8 to eliminate the brake torque and to drive the motor 16. In the case of quickly stopping the main driving shaft 4, the supply of electric current to the motor 16 is stopped and, at the same time, a normal direction voltage of 2-4 times the rated voltage of the permanent magnet brake is applied to the electromagnet 14 to quickly stop the main driving shaft 4 by the braking force consisting of the force of the electromagnet 14 in addition to the attraction force of the permanent magnet 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device for an automatic loom.

[0002]

2. Description of the Related Art A main drive shaft driven by a motor of an automatic loom is connected to an exciting electromagnetic brake. Alternatively, the main drive shaft is linked to the excitation type brake motor. There is also a main drive shaft that is connected to the excitation type clutch / brake. When the yarn of the automatic loom is broken, the main drive shaft is suddenly braked by these exciting electromagnetic brakes. A conventional drive device for an automatic loom, as shown in FIG. 4B, applies an overvoltage of 4 to 6 times the rated voltage to an electromagnetic brake in a short time, as shown in FIG. The braking force is maintained by applying the rated voltage after that.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention A conventional drive device for a loom using an excitation type electromagnetic brake cannot hold braking force at the time of power failure. Moreover, the braking force is obtained only by the attraction force generated from the electromagnetic coil. Therefore, during braking, the rise time of the brake current after energization rises according to the coil time constant, so the rise of the brake torque is delayed as shown in D of FIG. 4, and the main drive shaft cannot be suddenly stopped as shown in FIG. 4A. There was a flaw. If the main drive shaft is not stopped promptly after the yarn breakage is detected, the automatic loom will be difficult to perform the yarn breakage repair work depending on the position of the reed and will have to make a fine movement by inching. Further, when the loom is started, the brake is released and the motor is started at the same time, and the brake torque disappears according to the time constant of the brake coil. Therefore, as shown in FIG. 4E, there is a lot of interference between the motor torque and the brake torque at the start. Therefore, the motor starting current becomes high. The present invention aims to solve the above problems.

[0004]

In order to achieve the above object, the present invention relates to a drive device for an automatic loom in which a weaving operation is performed by the rotation of a main drive shaft driven by a motor. It is equipped with a non-excitation actuated permanent magnet brake that brakes and holds it with attractive force and releases it with the repulsive force of the electromagnet.

[0005]

When the vehicle is stopped, the braking force is retained on the main drive shaft. 2 of rated voltage of permanent magnet brake
When a magnetic flux is generated in the same direction as the magnetic flux generated by the permanent magnet by applying a voltage of ˜4 times, this magnetic flux and the magnetic flux of the permanent magnet synergistically act as a braking force on the main drive shaft. Since the magnetic flux of the permanent magnet already exists, the brake torque rises quickly when the power supply to the coil of the electromagnet is turned off. When releasing the brake, since the magnetic flux in the opposite direction to the magnetic flux of the permanent magnet is generated from the electromagnet, it becomes reverse excitation,
The brake torque disappears quickly. Further, by applying a reverse voltage equal to or higher than the rated voltage, the disappearance time of the brake torque can be controlled.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below in detail with reference to the embodiments shown in the accompanying drawings. An automatic loom 2 includes a main drive shaft 4. In the automatic loom 2, the reeds 6 and the like are driven by the power transmitted from the main drive shaft 4, and a textile manufacturing operation is performed. A permanent magnet brake 8 and a belt pulley 10 are connected to the main drive shaft 4.

The permanent magnet brake 8
Is braked and held by the attractive force of the permanent magnet 12, and the electromagnet 14
It is a non-excitation actuated boulek which is released by the repulsive force of. 1
Reference numeral 6 denotes a motor fixedly installed in the machine body. A belt pulley 18 is fixed to the output shaft of the motor, and an endless V belt 20 is hung between the belt pulley 18 and the belt pulley 10.

In the above structure, the rotation of the output shaft of the motor 16 is transmitted to the main drive shaft 4 via the belt pulleys 18 and 10. When the automatic loom 2 is started, the motor 16 is energized to drive the motor 16. At this time, a reverse voltage equal to or higher than the rated voltage is applied to the electromagnet 14 of the permanent magnet brake 8 to cause the electromagnet 14 to generate a magnetic flux in a direction opposite to the magnetic flux of the permanent magnet 12. This allows
The electromagnet 14 is reversely excited, and the braking torque of the permanent magnet brake 8 disappears quickly.

The main drive shaft 4 becomes full speed immediately after starting the automatic loom. If the main drive shaft 4 does not reach the full speed promptly after starting, the force of the reinforcement 6 striking the weft thread 22 is not constant and uneven weaving occurs. Since the brake torque shown in FIG. 3D disappears promptly, there is little interference between the motor torque and the brake torque at the time of starting the automatic loom, and the starting current of the motor 16 can be kept low as shown in FIG. 3E.

When the main drive shaft 4 is stopped, the power supply to the motor 16 is stopped. On the other hand, a voltage that is 2 to 4 times the rated voltage of the permanent magnet brake 8 is applied in the same direction as the magnetic flux generated by the permanent magnet 2 of the permanent magnet brake 8.
A magnetic flux is applied to the electromagnet 14 so that a magnetic flux is generated in the electromagnet 14. As a result, the permanent magnet brake 8
3B, the brake torque due to the attraction force of the permanent magnet 12 and the brake torque due to the attraction force of the electromagnet 14 are added to generate a large brake torque as shown in FIG. 3D, and the main drive shaft 4 is rapidly stopped.

In a so-called inching operation in which the main drive shaft 4 is moved little by little, the on / off control of the motor 16 and the on / off control of the permanent magnet brake 8 are performed at minute time intervals. It rapidly rises up to the number of revolutions and stops immediately.

[0012]

[Effect] Since the present invention is configured as described above, the following effects are present. (1) 2 of rated voltage of permanent magnet brake
By applying a voltage of up to 4 times and generating a magnetic flux in the same direction as the magnetic flux generated by the permanent magnet in the electromagnet, it is possible to generate a synergistic braking force in the permanent magnet brake, which allows the main drive shaft to move quickly. Can be stopped. (2) The main drive shaft can be held in a braking state during a power failure. (3) When the main drive shaft is braked, since the magnetic flux of the permanent magnet already exists in the permanent magnet brake, the rise time of the brake torque after turning off the electromagnet of the permanent magnet brake is short. (4) When the braking of the main drive shaft is released, the magnetic flux in the direction opposite to the magnetic flux of the permanent magnet of the permanent magnet brake is positively generated by the electromagnet, so that reverse excitation occurs and the brake torque disappears quickly. The disappearance time of the brake torque can be controlled by applying a reverse voltage higher than the rated voltage to the electromagnet of the permanent magnet brake. Therefore, the drive shaft can be rapidly started.

[Brief description of drawings]

FIG. 1 is an external view of a drive unit for an automatic loom.

FIG. 2 is a sectional view of a permanent magnet brake.

FIG. 3 is an operation explanatory diagram of the present invention.

FIG. 4 is an operation explanatory diagram of a conventional technique.

[Explanation of symbols]

 2 Automatic loom 4 Main drive shaft 6 Reed 8 Permanent magnet brake 10 Belt pulley 12 Permanent magnet 14 Electromagnet 16 Motor 18 Belt pulley 20 V belt 22 Weft

Claims (1)

[Claims] 1. A drive device for an automatic loom in which a weaving operation is performed by rotation of a main drive shaft driven by a motor, wherein the main drive shaft is braked / held by an attractive force of a permanent magnet,
A drive device for an automatic loom, which is equipped with a non-excitation actuated permanent magnet brake that is released by the repulsive force of an electromagnet.