JPH02139456A - Multicolor free selector of weaving machine - Google Patents

Abstract

PURPOSE:To control electric current of DC motor at a sufficiently rapid period by providing a chopper control circuit with a velocity order synchronized with a synchronous signal of weaving machine depending upon revolution speed pattern of length measuring drum outputted based on a warp selective order. CONSTITUTION:A first memory 4 which memorizes plural revolution speed patterns D of a length measuring drum 2 and outputs given revolution speed patterns D based on selective order E and a chopper control circuit 6 which controls revolving speed and speed increasing or reducting of a DC motor 3 depending upon change of conduction ratio of armature current are set and a control device 8 provides the chopper control circuit 6 with velocity order I synchronized with a synchronous signal of weaving machine based on the revolution speed patterns outputted from the memory 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a multi-color free selection device for a loom, and particularly to rotation control of a length measuring drum driving motor.

[Conventional technology]

The multicolor free selection method allows you to freely select a plurality of weft yarns depending on the type of woven fabric.

The measuring drum of each weft insertion device measures the weft necessary for weft insertion in advance and stores it until the time of weft insertion. It will rotate to . If the length-measuring drum temporarily stops during this operation, the storage state of the weft becomes unstable due to the occurrence of warping of the spun yarn, so it is necessary to keep it rotating continuously at an appropriate rotation speed. desirable. Therefore, in order to stabilize the weft insertion state, the rotational speed pattern of the motor for driving the length measuring drum is set to appropriate acceleration/deceleration characteristics depending on the type of yarn, that is, the ease with which chattering occurs.

[Issues with conventional technology]

The rotation speed pattern control described above requires wide range speed control and rapid acceleration/deceleration. Normally, this type of DC motor is controlled by a cyrisk phase control method, and its control range is limited to 1/2 cycle of the commercial power supply. For this reason, the Cyrisk phase control method cannot achieve high-speed response or smooth acceleration/deceleration control.

[Summary of the invention]

Therefore, an object of the present invention is to enable rapid acceleration/deceleration control of a DC motor.

On the other hand, if sudden acceleration/deceleration control is performed, length measurement errors are likely to occur due to the response speed of the DC motor, slippage of the weft yarn on the length measurement drum, etc.

Therefore, another object of the present invention is to improve the accuracy of length measurement,
The purpose is to accurately prepare the length of the weft yarn required for weft insertion, with just the right amount and the right amount.

〔Example〕

Hereinafter, the basic idea and embodiments of the present invention will be explained in detail based on the drawings.

First of all, Figure 1 shows the drum rotation speed when performing continuous length measurement.
, weft flying speed V, are shown in relation to time. In the same figure, 1. 1. ... t4 indicates the weft insertion start timing, and specifically coincides with the opening timing of the clamper of the weft insertion device. Also T I, T 2...
T4 is the timing at which weft insertion is completed, and specifically coincides with the closing timing of the clamper. And ■. is -
C is the value that is said to be the average weft insertion speed, and the area of the shaded area of the drum rotation speed ■ and the area of the shaded area of the weft flying speed ■ correspond to the length of the weft, and of course they match. .

Now, in the case of free selection, the drum rotation speed at the time of weft switching becomes a problem. The following two conditions are required at this time.

(1) The necessary length must be prepared by the time of the next weft insertion.

(2) At the time of entering the restraint flight, the drum rotational speed V is the average weft insertion speed V0.

Next, FIG. 2 shows the drum rotation speed ■ during intermittent operation in relation to time t. 1. ．． 1c, shi, and 1c are the timings when weft insertion is completed, and L is the timing when the speed is reduced to zero due to stopping.

Now, assuming that another weft is inserted between t and 1c, in order to satisfy the above condition (1),
The area of the shaded area in the figure must match the area of the shaded area. In order to prevent weft breakage or overrun during weft insertion, it is desirable that the speed change be as gentle as possible. However, on the other hand, if the rotational speed of the length measuring drum is zero, that is, if the weft yarn is not pulled out, for example, a yarn with a large amount of twist may cause a problem of burr. In this case, it is preferable to keep the length measuring drum rotating continuously at a slow speed without stopping the rotation.

FIG. 3 shows the change in the drum rotational speed (■) in relation to time when the speed value is changed to achieve continuous rotation. Here again, the measured lengths (shaded areas in FIGS. 2 and 3) must be equal, so in the case of continuous rotation, rapid rise and fall of the speed is required.

Therefore, the present invention changes the rotational speed pattern of the measuring drum depending on the weakness of the weft yarn and the ease with which chattering occurs, and stores a plurality of rotational speed patterns in advance in a storage device in order to provide an appropriate rotational speed pattern. , they are selectively read out and the rotation of the length measuring drum is controlled based on the speed characteristics. Note that the low speed V during continuous rotation can be set by predicting in advance the number of picks after which the next weft insertion will be performed.

Further, in order to achieve the above object, the present invention employs a direct current (DC) motor as a drive source for the length measuring drum, and controls the current of the motor by a shifter control circuit. In other words, the Nayosover control circuit inputs DC voltage from a DC power supply,
The conduction ratio of the current is set to a high frequency, for example, 10% of the commercial frequency.
By changing the frequency at about double the frequency, the average current of the armature current of the DC motor is adjusted, and rapid acceleration/deceleration is realized with smooth characteristics.

By the way, even if the above-mentioned high-speed response can be achieved, in actual control, as shown in Figure 4, due to delays in the mechanical system, the target speed command pattern A and the DC motor response speed pattern B may not match. Between 1. During acceleration and deceleration, an error ΔV occurs due to the time delay Δt. In order to eliminate this error, the present invention sequentially performs necessary corrections in advance according to feedback control and the characteristics of the weft and cloth.

FIG. 5 shows a multicolor free selection device 1 for a loom according to the present invention.

This multicolor free selection device 1 includes a plurality of length measuring drums 2, for example, two length measuring drums 2 for measuring and storing the length of the weft, a DC motor 3 for driving each length measuring drum 2, and a plurality of length measuring drums 2 for measuring and storing the weft lengths. A first storage device 4 which stores a rotational speed pattern D in advance and outputs a predetermined rotational speed pattern D based on a selection command; A second storage device 5 for storing data, the above-mentioned D
A chopper control circuit 6 that controls the rotation speed and acceleration/deceleration of the C motor 3 by changing the conduction ratio of the armature current, a pulse generator 7 such as a shaft encoder that detects the amount of rotation of each of the length measuring drums 2, and the first The selected rotational speed pattern D is read from the storage device 4, and based on this rotational speed pattern D, a speed command I is given to the chopper control circuit 6, and an appropriate correction value C is sent from the second 41f1 device 5. The control device 8 reads out the correction value C and the rotation amount from the pulse generator 7, that is, the feedback signal, and controls the rotation of each DC motor 3.

The control device 8 also includes a storage device 9 for storing the weft insertion selection order, a step display device 10 for displaying the weft insertion steps, a correction value C1 rotation speed pattern D, a weft insertion selection command E, An input device 11 for inputting the length measurement amount F is attached. Furthermore, this control device 8 takes in from the outside a loom synchronization signal G, a loom rotational speed H, and a signal from a step forward or backward step detection switch 12, and performs control operations in synchronization with the m loom. The weft insertion step is also displayed by the step display device 10. The output of this control device 8 is connected to a D/A conversion circuit 13 and a chopper/control circuit 6, respectively.
is applied to the DC motor 3 through the
It is applied to a clamper 15 for holding down the weft yarn.

As shown in FIG. 6, the chopper control circuit 6 has a DC power supply circuit 17 connected to an AC power supply 16, and control transistors 18, 19, . The emitters and collectors of 20 and 21 are connected in a bridge shape, and the DC motor 3 (armature) is connected to the connection point of the emitters and collectors, and the drive circuit 22 is connected to the base of each of the transistors 18, 19, 20, and 21. Connect and configure. Here, a in the figure,
bsc, d indicate the correspondence relationship between the base and the drive circuit 22. This drive circuit 22 synchronizes with the pulses of the pulse generating circuit 23 to operate the transistors 18 .
19. Send drive control signal to base of 20.21.

The frequency of this control signal is given by the signal level of the speed command I from the D/A conversion circuit 13.

Now, when the operator operates the input device 11 and inputs the information of the selection command E into the control device 8, the control device 8 reads the corresponding weft insertion selection order program from the storage device 9, and
Set the weft insertion order.

Of course, the storage device 9 can be configured in advance through the input device 11.
Stores data on weft insertion order. At the same time, a predetermined rotational speed pattern D, length measurement amount F, and correction value C are designated through the human-powered device 11. In this way, the control device 8 stores the rotational speed of the DC motor 3 corresponding to the length measurement amount F, and also stores the rotational speed pattern D in the specified first
The correction value C is read from the specified address in the storage device 4, and the correction value C is read from the storage address in the second storage device 5 and stored.

When the loom enters the operating state, the control device 8 inputs the synchronization signal G and rotation speed H of the loom, and controls D in synchronization with the movement of the loom.
A speed command is given through the /A conversion circuit 13 and the chopper control circuit 6, and the DC motor 3 is controlled under the selected rotational speed pattern D. In this way, the DC motor 3 rotates at the average weft insertion speed Vo in the selected section based on the specified weft insertion order, and measures the weft length, while maintaining a low speed ■ in the non-selected section. , in preparation for the next weft insertion period. Furthermore, the clamper 15 harmoniously performs the weft gripping and releasing operations in synchronization with the movement of the m machine at the timing already described.

Here, the chopper control circuit 6 changes the conduction ratio at a frequency higher than the commercial frequency and controls the average value of the armature current of the DC motor 3 after a steep rise or fall. No. 3 continues to rotate even in the non-selected section, and does not stop until the next weft insertion starts to prevent warping.

On the other hand, the pulse generator 7 detects the actual rotation amount of the DC motor 3 and sends it to the control device 8 as a feedback signal. Therefore, the control device 8 compares the amount of rotation of the DC motor 3, that is, the length measuring drum 2, with the target amount of rotation at that time based on the feedback signal, gives a speed command I in a direction to eliminate the deviation, and at the same time A correction value C corresponding to the speed characteristic and the type of weft is read from the second storage device 5, and the rotation speed of the DC motor 3 is corrected using that value. For this reason, the rotational speed of the DC motor 3 is controlled with high precision, so that the actual measured length of the weft can be accurately prepared without excess or deficiency.

Furthermore, each time weft insertion is performed in a certain order, the signal from the strip detection switch 12 is input to the control device 8.
The control device 8 counts the signals and displays the step display device 1.
Display as 0. In this way, the control device 8 performs functions such as rotation commands and operation commands for the clamper 15 based on the loom synchronization signal G and rotational speed pattern D, as well as error correction and step display. It can be progressed at high speed in a divided state. Therefore, this control device 8 can actually be composed of a CPU module or the like. Further, the first storage device 4 and the second storage device 5 are configured by combining FROM, RAM, and the like.

〔Effect of the invention〕

The present invention has the following unique effects.

First, since several rotational speed patterns are stored in advance, an appropriate speed pattern can be selected depending on the shape of the yarn feeder, the release speed, etc., and therefore ideal rotational speed control of the C motor is possible.

Next, since the current of the motor for driving the length measuring drum is controlled by the chopper control circuit, the current can be controlled at a cycle sufficiently faster than the commercial frequency, and various acceleration/deceleration speeds can be easily obtained. Response can be achieved, and continuous rotation at low speed is possible even during non-selection periods.

Furthermore, in embodiments where errors caused by delays in the mechanical system, errors in length measurement due to slips, etc. are determined experimentally in advance, and appropriate corrections are made based on these, the negative effects of high-speed response can be eliminated. , high length measurement accuracy can be ensured.

[Brief explanation of the drawing]

Figure 1 is a characteristic diagram of the drum rotational speed and weft flying speed versus time, Figures 2 and 3 are velocity characteristic diagrams of the drum rotational speed on the time axis, and Figure 4 is a time delay between the target speed and error. FIG. 5 is a block diagram of a multi-color free selection device for m-machines according to the present invention, and FIG. 6 is a circuit diagram of a chopper control circuit. 1. Multicolor free selection device for loom, 2. Length measuring drum, 3
... DC motor, 4.. First storage device, 5.. Second storage device, 6.. Chopper control circuit, 7.. Pulse generator, 8.. Control device, 9.. Storage device, 11.. Input device, 13... D/A conversion circuit, 14... Driver 15
・・Clumber Diagram F Diagram T →

Claims (1)

[Claims] a first storage device that stores a plurality of rotational speed patterns of the length measuring drum and selectively outputs them based on a weft selection command; a motor that drives the length measuring drum; and a DC voltage obtained by smoothing a commercial power supply to the motor. a chopper control circuit that performs chopping control by changing the conduction ratio of current according to a rotational speed pattern; and a control device that provides the chopper control circuit with a speed command synchronized with a synchronization signal of the loom based on the rotational speed pattern. A loom multicolor free selection device consisting of.