JPH0335418B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing weaving steps, and more particularly to a method for applying a supply voltage to a motor when starting a loom.

When the loom is stopped, the yarn is in a different state than when it is in steady operation due to slack and tension. Therefore, if the loom is started after it has stopped and goes directly into steady operation, weaving steps will occur before and after the corresponding position at the time of startup. The form of this weaving step varies depending on the fabric, especially the yarn type, but if the yarn becomes loose while the stand is stopped, the reed beating force generated by the motor torque during start-up operation will not be enough to drive the weft yarns, resulting in a thin weave. On the other hand, if the yarn is sagged while the machine is stopped, the reed striking force due to the motor torque of the start-up operation will cause the weft to be driven in excessively, and thick steps will easily occur.

An object of the present invention is to suppress the occurrence of such thin steps and thick steps during startup.

That is, in this invention, when the loom is started, a high voltage is applied between the primary windings of the loom drive motor to increase the starting torque, and the application time of the high voltage is increased when a thin stage occurs, and increases when a thick stage occurs. It is meant to be shortened.

As a result, in the case of fabrics that tend to generate thin corrugations, a strong reeding force is obtained for a while after startup, so during this period the weft yarn is driven in more strongly than during steady operation, and the loosening of the yarn during standstill reduces the tendency for thin corrugation to occur. will be reduced. On the other hand, in the case of fabrics that tend to have thick corrugations, the reed striking force of steady operation is weakened in a short time after starting, so the tendency for thick corrugation to occur due to yarn tension during standstill is reduced.

In the present invention, the basis for changing the torque of the motor by adjusting the voltage applied between the primary windings of the motor is as follows.

Generally, the motor torque T is expressed by the following formula.

T=m・E・I・COSΘ・P/4πf・9.8 m...Constant E...Secondary voltage I...Secondary current P...Number of motor poles f...Power frequency Θ...Phase angle of magnetic flux and current In other words, torque T is Equal to the secondary power divided by the synchronous angular velocity. Since the voltage applied between the primary windings of the motor, that is, the primary voltage, is proportional to the secondary voltage and current, the motor torque is ultimately equal to 2 of the primary voltage.
It will be proportional to the power.

Here, if the motors have the same structure, the primary winding should be Y.
The primary voltage is higher when the Δ (delta) connection is used than the (star) connection, and the torque when starting the motor is also 2 to 9 times higher. Even if the same Δ (delta) connection is maintained, high torque can be obtained over a certain period of time by temporarily applying a voltage higher than the power supply voltage. In other words, a large reed striking force can be obtained during this period.

The present invention will be explained in more detail below with reference to the accompanying drawings.

What is shown in FIGS. 1 and 2 is an example of an apparatus for carrying out the present invention. In Fig. 1, motor M
has stator windings C1-C3, each winding having a respective terminal U-X, U-Y and W-Z. These windings C1 to C3 are equipped with magnetic contactors.
Power is supplied from a power source (not shown) via MC1 to MC3.

More specifically, the first terminals U, V, and W of each of the windings C1 to C3 are connected to the power source via a magnetic contactor MC1. These first terminals U, V, W
are connected to the second terminals Z, X, through the electromagnetic contactor MC2.
Each is connected to Y, and the magnetic contactor MC2
When closed, the first terminals U, V, W and the second terminals Z, X, Y are short-circuited. second terminals X, Y,
One contact of the electromagnetic contactor MC3 is connected to Z, and the other contact of the electromagnetic contactor MC3 is short-circuited. Therefore, when the electromagnetic contactor MC3 is closed, the second terminals X, Y, and Z are short-circuited to each other.

Operation of electromagnetic contactors MC1 to MC3 (i.e. opening/closing)
is controlled by the circuit shown in FIG. This circuit includes relays R1 to R3 and a time limit relay TR, and when these are energized, the corresponding relay contacts and electromagnetic contactors perform predetermined operations.

That is, when relay R1 is energized, relay a contact R
1a and the magnetic contactor MC1 change from open to closed.
When relays R2 and R3 are energized, relay b
Contacts R2b and R3b each change from closed to open, and electromagnetic contactors MC2 and MC3 each change from open to closed. Further, when the time limit relay TR is energized, the time limit operation contact TRa and the time limit operation contact B TRb change from open to close and from close to open, respectively, after a predetermined period of time has elapsed.

These relays R1-R3 and time-limited relays
One end of each TR is connected to one output terminal of the power supply. Moreover, the switch S1 and one terminal of the relay a contact R1a are connected to the other output terminal of the power supply, and the relay a contact R1a is also connected to the other output terminal of the power source.
The other terminal of is connected to switch S via switch S2.
1 is connected to the other terminal of 1. Here, the switches S1 and S2 are switches each comprising a manually operated automatic return contact.

The other end of the relay R1 and the time limit relay TR are connected to the other terminal of the switch S1. Also, at the other end of the switch S1, there is a time-limited operation b contact.
Relay R via TRb and relay b contact R3b
The other end of 2 is connected. Furthermore, the switch S1
The other end of the relay R3 is connected to the other end of the relay R3 via a time-limited operation a contact TRa and a relay b contact R2b.

The operation of the apparatus having the above configuration will be explained in order below.

When starting the loom, first turn on switch S.
Press 1. This energizes relay R1, time limit relay TR, and relay R2. Relay R
1 is energized, relay a contact R1a changes from open to closed. Since the self-holding circuit of the relay R1 is closed, even if the switch S1 is released from the press in this state, the energization of the relay R1, time limit relay TR, and relay R2 is maintained. Further, by energizing relays R1 and R2, relay b contact R2b changes from closed to open. FIG. 3B shows a state in which the switch S1 is pressed down.

Furthermore, by energizing the relays R1 and R2, the electromagnetic contactors MC1 and MC2 are changed from open to closed, respectively, and as a result, the primary windings C1 to C3 of the motor M are as shown in FIG. 3A.
The connection is Δ (delta) as shown in . Therefore,
Electric power is supplied from the power source by the operation of the electromagnetic contactor MC1, current flows through the primary windings C1 to C3 of the motor M, the motor M starts rotating, and the loom starts operating accordingly.

The primary windings C1 to C3 at startup are Δ
(Delta) connection, the voltage value applied between each winding is approximately √3 times that of a Y (Star) connection, and the torque of the motor M increases accordingly.

When a predetermined period of time has passed after the loom is started (that is, after switch S1 is pressed), the time limit relay TR operates,
Time-limited action contact TRa changes from open to close, time-limited action B
Contact TRb changes from closed to open. When the time-limited operation b contact TRb is opened, the current to the relay R2 is cut off, so the relay b contact R2b changes from open to closed. In addition, since the time-limited operation contact TRa is also closed, relay R3 is energized, and relay b contact R
3b changes from closed to open. This state is shown in FIG. 4B. At what point after startup is the time-limited relay TR activated?
Whether or not to operate it is determined depending on the tendency of the woven fabric to generate weaving steps.

Furthermore, electromagnetic contactor MC3 is activated by energizing relay R3.
changes from open to closed, and because relay R2 is de-energized, electromagnetic contactor MC2 changes from closed to open. As a result, the primary windings C1 to C3 of the motor M are
This is a Y (star) connection as shown in the figure.

Since the windings C1 to C3 are connected in a Y (star) connection in this way, the voltage value applied between each winding is lower than when they are connected in a Δ (delta) connection, and the torque of the motor M is reduced. will also decrease accordingly.

To stop the loom from the operating state, it is sufficient to press the switch S2. When switch S2 is pressed down, power is cut off to relays R1, R3 and time limit relay TR. As a result, relay a contact R1a and time-limited action a contact TRa change from closed to open, while relay b contact R3b and time-limited action b contact
TRb changes from open to closed, returning to the state shown in FIG.

The electromagnetic contactor is activated by opening relay R1.
MC1 is opened, the power supply to the motor M is cut off, the motor M stops, and the loom also stops. Also, because relay R3 is open, the electromagnetic contactor
MC3 is also opened, the connection between the windings C1 to C3 is released, and the state shown in FIG. 1 is restored.

As described above, according to the present invention, since the switching point from high voltage operation to steady operation is determined according to the tendency of weaving steps to occur in the fabric to be woven, an appropriate reed beating force can always be obtained and the occurrence of weaving steps can be prevented. It is significantly suppressed.

Next, another example of the apparatus for carrying out the method of the present invention will be described with reference to FIGS. 5 and 6.

In the following explanation, the principle of the right wheel will be used. Fifth
In the control circuit shown in the figure, the leftmost terminal A is connected to a preparation start switch (not shown). Preparation here refers to work such as turning on the blower, preheating the heater, and turning off the fiber cutting stand indicator lamp before starting the operation of the loom. Terminal B
is connected to the operation switch S2 of the loom and the weft and weft cutting stop signal generator, and the terminal C is connected to the operation start switch S1.
are connected to each. Therefore, when these switches are pressed, these terminals A, B, and C
A logical ``1'' appears in each of them. Terminal D at the right end is connected to the star connection system in the circuit shown in FIG. 2, terminal E to the delta connection system, and terminal F to the motor rotation system. Therefore, when a logic "1" appears at these terminals D, E, F, the respective connected systems are energized.

Terminal A is connected to the set terminal S of the first flip-flop 1. Terminal B is connected to the reset terminal R of the first flip-flop 1 and the reset terminal R of the second flip-flop 3, respectively. Terminal C is the first AND element 2
is connected to the second input terminal of. Note that the first input terminal of the AND element 2 is connected to the output terminal of the first flip-flop.

The output terminal of the first flip-flop 1 is also connected to the first input terminal of an OR element 7 via an inverter 6. The output terminal of this OR element 7 is connected to the first input terminal of a second AND element 9, and the output terminal of this AND element 9 is connected to the star connection system terminal D.
It is connected to the.

The output terminal of the first AND element 2 is connected to the second flip. It is connected to the set terminal S of the flop 3. The output of the second flip-flop 3 is connected to the input of a one-shot multivibrator 4. In this example, the input holding time t of the multivibrator 4 is set to 150 to 1000 ms. The output terminal of this multivibrator 4 is directly connected to the terminal E for the delta connection system, and is also connected to the second input terminal of the second AND element 9 via the inverter 8.

The output of the second flip-flop 3 is also connected to the input of the delay circuit 5. In this example, the delay time is set to 40ms. The output terminal of the delay circuit 5 is connected to the second input terminal of the OR element 7 on one side, and to the motor rotation system terminal F on the other side.

First, starting from the operating state, logic "0" appears at each terminal A, B, and C since none of the switches are pressed at this point. Therefore, a logic "1" is present at the output of the first flip-flop. This logic "1" is inverted via the inverter 6 to become logic "0" and is input to the first input terminal of the OR element 7, and the first
is input to the first input terminal of the AND element. Since the logic "0" from the terminal C is input to the second input terminal of the AND element 2, the AND element 2 outputs the logic "0" and the set terminal S of the second flip-flop 3 is input. give this to. On the other hand, the flip
Since the reset terminal R of the flip-flop 3 receives a logic "0" from the terminal B, a logic "1" appears at the output of the flip-flop 3. In response to this, the multivibrator 4 outputs logic "0". Since this is applied to terminal E, the delta connection system will not be energized. The output logic "0" of the multivibrator 4 is inverted by the inverter 8 to become a logic "1" and input to the second input terminal of the second AND element 9.

Output logic “1” of second flip-flop 3
On the other hand, since it is directly applied to the terminal F via the delay circuit 5, the motor rotation system is excited. On the other hand, since the logic "1" is applied to the second input terminal of the OR element 7, the OR element 7 outputs a logic "1", which is applied to the first input terminal of the second AND element 9. Since the second input terminal of this AND element 9 receives the inverted logic "1" from the multivibrator 4 as described above, the AND element 9 outputs a logic "1", which is transmitted to the terminal D. is given, so the star connected system is energized. That is, in the apparatus shown in FIG. 1, the motor rotates in a star line state while the loom is operating.

When the loom stops, logic “1” is applied only to terminal B.
appears, and the other terminals A and C are in the logic "0" state. A logic "1" from terminal B resets the first flip-flop 1 so that a logic "0" appears at its output. This logic "0" is inverted by the inverter 6 to become a logic "1" and is input to the OR element 7, so the OR element 7 outputs a logic "1". The logic "1" from the output of the first flip-flop 1 is input to the first input of the first AND element 2. Since the logic "0" from the terminal C is input to the second input terminal of the AND element 2, the AND element 2 outputs the logic "0" and the set terminal S of the second flip-flop 3 is input. give this to. Since the reset terminal R of the flip-flop 3 receives a logic "0" from the terminal B, a logic "0" appears at its output terminal. In response to this, the multivibrator 4 outputs logic "0". Since this is applied to terminal E, the delta connection system will not be energized. The output logic "0" of this multivibrator 4 is inverted by the inverter 8 and becomes logic "1".
and enters the second input terminal of the second AND element 9.

Output logic “0” of second flip-flop 3
is applied as it is to the terminal F via the delay circuit 5, so the motor rotation system is not excited. The output logic "1" of the OR element 7 described above is applied to the first input terminal of the second AND element 9. Since the second input terminal of this AND element 9 receives the inverted logic "1" from the multivibrator 4 as described above, the AND element 9 outputs a logic "1", which is transmitted to the terminal D. is given, so the star connected system is energized.

That is, in the apparatus shown in FIG. 1, when the loom stops, the star connection remains, but the motor does not rotate.

When preparations are made prior to the start of operation of the loom, logic "1" appears only at terminal A, and the other terminals B and C are at logic "0". Logic “1” from terminal A
As a result, the first flip-flop 1 is set and a logic "1" appears at its output. This logic "1" is inverted by the inverter 6 to become a logic "0" and is input to the OR element 7, and is also input as is to the first input terminal of the first AND element 2. Since the logic "0" is input from the terminal C to the second input terminal of the AND element 2, the AND element 2 outputs the logic "0", which is input to the second input terminal.
is applied to the set terminal S of flip-flop 3. Since the reset terminal R of the flip-flop 3 receives a logic "0" from the terminal B, a logic "0" appears at its output terminal. In response to this, the multivibrator 4 outputs logic "0". Since this is applied to terminal E, the delta connection system is not energized. The output logic "0" of the multivibrator 4 is inverted by the inverter 8 to become a logic "1" and input to the second input terminal of the second AND element 9.

Output logic “0” of second flip-flop 3
is directly applied to the terminal F via the delay circuit 5, so the motor rotation system is not excited, and on the other hand, it is applied to the second input terminal of the OR element 7, so the OR element 7 eventually becomes It outputs a logic "0" and applies it to the first input terminal of the second AND element 9. As mentioned above, the inverted logic "1" from the multivibrator 4 is input to the second input terminal of the AND element 9, but the OR element 7
Because of the input logic "0" from the AND element 9, the AND element 9 eventually outputs a logic "0", which is applied to the terminal D, so that the star connection system is also not energized.

That is, in the apparatus shown in FIG. 1, the windings C1 to C3 of the motor M are not connected while the loom is being prepared.

When the loom starts operating, logic "1" appears only at terminal C, and the other terminals A and B are at logic "0". Since the set terminal S of the first flip-flop 1 receives the logic ``0'' from the terminal A, and the reset terminal R receives the logic ``0'' from the terminal B, its output terminal maintains the logic ``1''. . This logic "1" is inverted by the inverter 6, becomes logic "0", and is input to the OR element 7.
It is applied as is to the first input terminal of the first AND element 2. Since the logic "1" from the terminal C is input to the second input terminal of the AND element 2, the AND element 2 outputs the logic "1", which is sent to the set terminal of the second flip-flop 3. I will give it to S.
Flip-flop 3 is set so that a logic "1" appears at its output Q.

Now, this logic "1" enters the delay circuit 5, and the logic "1" is outputted from the delay circuit 5 with a delay of 40 seconds. Therefore, at terminal F, in this example, logic "0" appears for 40 ms after startup, and logic "1" appears after 40 ms.

The logic "1" also enters the OR element 7 with a delay of 40 ms, and the OR element 7 outputs a logic "1" which is applied to the first input of the second AND element 9.

Since the logic "1" from the output terminal of the second flip-flop 3 is input to the multivibrator, the multivibrator 4 is activated after starting at tms (150
≦t≦1000), a logic "1" is output, and after tms, a logic "0" is output.

Therefore, a logic "1" appears at terminal E for tms after startup, and the delta connection system is excited, and in the device shown in FIG. 1, the motor rotates in the delta connection state.
During this time, the output logic of multivibrator 4 is “1”
is inverted by the inverter 8, becomes a logic "0", and is input to the second input terminal of the AND element 9. Therefore, a logic "0" is input from the AND element 9 to the terminal D, and the star connection system is not excited. .

When tms has elapsed after startup, a logic "0" appears at terminal E, so the delta connection system is no longer energized, and the delta connection state is released in the device of FIG. At the same time, the output logic "0" of the multivibrator 4 is inverted by the inverter 8, becomes a logic "1", and is inputted to the second input terminal of the AND element 9, so the logic "1" is output from the AND element 9 to the terminal. D is input, the star connection system is excited,
In the device shown in Figure 1, the motor rotates in a star-connected state.

That is, by adjusting the one-shot multivibrator to a predetermined time, it is possible to change the point in time at which the delta connection is switched to the star connection.

Note that the specified time may vary depending on the yarn type.
Since the TMS changes, it goes without saying that you can adjust it using a timer, etc.

In the above description, as an example of a device for carrying out the method of the present invention, the primary winding of a loom driving motor is connected through a Δ (delta) connection, the loom is started, and a predetermined time has elapsed after starting. In the above, a type in which the winding is switched to a Y (star) connection was explained.

However, as another example of a device implementing such a method, a transformer such as a transformer or a reactor is interposed between the power supply and the input terminal of the loom drive motor, and the power supply voltage is transferred to the motor by the transformer at startup. One example is a type in which the voltage is increased and applied, and the power supply voltage is directly applied to the motor after a predetermined time has elapsed after startup.

As is clear from the above, according to the present invention, the high voltage application time at startup is lengthened or shortened in accordance with the thinness of the fabric where the weaving steps occur due to the stoppage, so the occurrence of weaving steps can be effectively suppressed. Can be done.

[Brief explanation of the drawing]

FIG. 1: A circuit diagram showing an example of an apparatus for carrying out the method of the present invention. FIG. 2: A circuit diagram of a circuit for suppressing the operation of the electromagnetic contactor in the device shown in FIG. 3A to 4B; Explanatory diagrams showing the operation of the apparatus shown in FIG. 1. FIG. 5; a circuit diagram showing another example of an apparatus for carrying out the method of the present invention. FIG. 6: A graph showing signal states of the control circuit. MC1~MC3...Magnetic contactor, C1~C3...
...Winding, M...Motor, U~W, X~Z...Motor input terminal, S1, S2...Switch, R1~
R3...Relay, TR...Time-limited relay, R1a...
...Relay a contact, R2b, R3b...Relay b contact, TRa...Time-limited action a contact, TRb...Time-limited action b contact.

Claims (1)

[Claims] 1. A high voltage is applied between the primary windings of the loom driving motor when the loom is started to increase torque, and a voltage is applied between the primary windings at the time when a predetermined time has elapsed after the loom is started. A method for preventing weaving steps, characterized in that in a loom in which the voltage is lower than the above-mentioned high voltage, the time for applying the above-mentioned high voltage is made longer when a thin step occurs, and shortened when a thick step occurs.