JPH0253941A - Operation apparatus for loom - Google Patents

Abstract

PURPOSE:To surely stop a loom in the case of malfunction of a control circuit by outputting an abnormal signal when the electrified state of a motor is detected after the cancellation of an operation order and opening a back-up breaker. CONSTITUTION:A discrimination unit 10 is connected to the output of a current transformer CT inserted in an S-phase power line in the middle of a motor M and a main contactor MC. The state-discrimination means of the discrimination unit 10 detects the electrified state of the motor M after the cancellation of an operation order. When the electrified state of the motor is detected after the cancellation of the operation order, an abnormal signal is outputted from the unit to open a back-up breaker such as an auxiliary contactor MC2 and stop the motor.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a system for safely stopping a loom even when the contacts of a loom operating device, particularly a main contactor for switching on and off a motor power supply, are welded. Concerning a devised operating device for a loom.

In conventional looms, if the main motor for operating the loom (hereinafter simply referred to as motor) does not stop reliably when the operation command is canceled, there is a risk of extremely large damage being caused. In other words, if the motor continues to operate when a cause of loom stoppage occurs, such as warp thread breakage or weft thread breakage, these troubles will eventually develop into the breakage of all C1 warp threads.
This is because its restoration requires an enormous amount of time and effort. Furthermore, it goes without saying that if the loom cannot be stopped when the loom is about to be stopped for some reason, this will lead to an extremely serious situation in terms of safety.

For looms, various trouble detection technologies have been developed and put into practical use in order to stop the loom as quickly as possible in the event of a stoppage. Special efforts have already been made to stop the system (for example, in the
33888).

When the stop switch is operated, if the motor does not stop for some reason, the main contactor is forcibly opened by operating a timer that measures the passage of a predetermined amount of time after the stop switch is operated. , it is possible to ensure the stopping operation of the motor.

Problem to be Solved by the Invention According to this prior art, when an abnormality occurs in the control circuit for associating the signal indicating that the stop switch has been operated with the return operation of the main contactor, it is difficult to deal with it appropriately. Even if it were possible to do so, there was a problem in that no countermeasures could be taken against the occurrence of an abnormality in the main contactor itself, such as a contact welding accident of the main contactor. In other words, since the main contactor generally opens and closes the motor power supply, the probability of an accident including welding of the main contact is extremely high.
Even if a contact relay, which is said to have low reliability, is used, it is usually easy to achieve much higher reliability than the main contactor. Therefore, in this conventional technology, °C is The unavoidable drawback is that the motor is completely defenseless against malfunctions in stopping the motor due to contact welding or the like.

Therefore, in view of the actual state of the prior art, an object of the present invention is to provide a new loom, which is capable of effectively dealing with accidents such as contact welding of the main contactor by providing a state determining means. Our goal is to provide driving equipment.

Means for Solving the Problems The configuration of the present invention to achieve the object includes a main contactor for switching the motor power supply that operates in response to a loom operation command, and a back-up switch inserted in series with the main contactor. , a state determining means for determining the energized state of the motor after the driving command is canceled, and outputting an abnormality signal when it is detected that the motor is in the energized state after the driving command is canceled, the state determining means detecting the abnormality. The gist is that the backup switch is opened based on the signal.

Note that a first auxiliary contactor that connects the motor windings in a delta connection and a second auxiliary contactor that connects the motor windings in a star connection are provided, and the motor windings are switched from the delta connection to the star connection to start the motor. At this time,
The second auxiliary contactor is configured to maintain its operating state even after the operation command is released, and the state determining means uses the second auxiliary contactor as a backup switch to open it based on the abnormality signal. It shall be permitted to do so.

Further, the state determining means may be activated after a predetermined set time has elapsed after the driving command is canceled.

Therefore, with this configuration, when the operation command is canceled during manual stop operation or when some cause of stoppage occurs, the main contactor returns and tries to stop the motor, but At this time, if the contacts of the main motor are welded, etc., and it fails to shut off the motor power,
The state determining means can detect this and output an abnormal signal, so if this abnormal signal is used to open the backup switch inserted in series with the main contactor, the
It is possible to stop the motor. Here, as the backup switch, a distribution switch with a shunt trip, a switch exclusively for backup protection provided in series with the main contactor, etc. can be used.

Note that the state determining means can also be applied to the case where the starting torque of the motor is increased by so-called delta star starting using the first and second auxiliary contactors.
At this time, connect the second auxiliary contactor for star connection,
It is possible to use it for backup switches.

When the state determination means is activated after a predetermined set time has elapsed after the operation command is canceled, the information source for determining the energization state of the motor is determined by the information that should be used at a predetermined time interval after the operation command is canceled, such as the motor rotation speed. It is possible to realize an appropriate discrimination function even when using

It works as described above.

Example Examples will be described below with reference to the drawings.

The operating device of the loom includes a main contactor MC for switching on and off the power supply for the motor M, and a first auxiliary contactor MCI for delta connection.
, a second auxiliary contactor MC2 for star connection, and a discrimination unit 10 (FIG. 1).

Motor M is a three-phase induction motor, and has terminals UX and VY.
, WZ, there are three independent windings. The main contact of the main contactor MC is interposed between the three-phase power supply R3T and the terminal UVW, and a current transformer CT is inserted in the S-phase power line between the main contactor MC and the motor M. be. The main contact of the first auxiliary contactor MCI is interposed between the terminal UvW and the terminal ZXY, while the terminal
YZ is short-circuited via the main contact of the second auxiliary contactor MC2. That is, when operating the main contactor MC, the power to the motor M can be opened and closed, and the first and second auxiliary contactors MCI and MC2 can switch the motor windings between delta connection and star connection, respectively. is now possible.

A discrimination unit 10 is connected to the output of the current transformer CT.

The determination unit 10 includes a state determination stage 11 and a timer 12.
and a setting device 13 (FIG. 2). That is,
The current signal Si, which is the output of the current transformer CT, is transmitted to the state determining means 1.
1, while the state determining means 11 has timer 1.
2 and the setting device 13 are input. An abnormality signal Sa is extracted from the state determining means 11 to the outside, and a normally closed contact R1b of a relay R1, which will be described later, is input to the timer 12.

The main contactor MC etc. are controlled via a relay control circuit (FIG. 3). A relay R1 is connected between the control power line AB via a start switch BSI, and a normally open contact R1a of the relay R1 and a stop switch BS2.
A timer TR is connected via a series circuit to a normally closed contact which is applied from the outside and indicates the presence of a cause of stoppage. The normally closed contact R1b of the relay R1 is input to the state determination unit 10 as described above.

Each control power line A side of relay R1 and timer TR is
Short-circuited to each other, drawn out as auxiliary control power line A1, and connected between relays R2 and R8 to control power line B.
, connect timer TRI and be 0, i.e. relay R2
is driven via on-delay normally closed contact TRb of timer TR and normally closed contact R3b of relay R3, while relay R3 and timer TRI are driven via on-delay normally open contact TRa of timer TR and normally closed contact TRa of relay R2. They are simultaneously driven via the closing contact R2b.

Main contactor MC and first and second auxiliary contactors MC
I and MC2 are relays R1, R2, and R3, respectively.
It is connected between the control power supply lines AB through the normally open contacts R1a, SR2as, and R3a. However, the second auxiliary contactor MC2 is also driven by a series circuit of the off-delay normally open contact TR1a of the timer TRI and the relay contact Sax. Here, the relay contact Sax is connected to the abnormality signal Sa from the discrimination unit 10.
This is assumed to be a normally closed contact of an auxiliary relay (not shown) that is operated by.

Now, when the start switch BSI is operated, the relay R1 is activated and self-holds via the normally open contact R1a, so that the operation command S is output (FIG. 4).

However, the presence or absence of the driving command S corresponds to the presence or absence of the voltage of the auxiliary control power supply line A1 in FIG.

When the operation command S is output, relays R1 and R2 are activated, so the main contactor MC and the first auxiliary contactor MC
I is turned on (Fig. 4), so the motor M becomes
Can be activated in delta connection state. Now, if the motor M is star-connected and has windings such that the power supply voltage of the three-phase power supply RS 'T' is the rated voltage, the motor M is capable of direct starting at the rated voltage. Approximately 3
It is possible to generate twice the starting torque, and therefore, the possibility of occurrence of weaving steps when starting the loom can be minimized.

Subsequently, as the set time tTR of timer TR elapses,
Since the timer TR operates, the first auxiliary contactor MC
I is opened and the second auxiliary contactor MC2
is turned on, the motor M is switched from the delta connection to the star connection, and its startup can be completed. From then on, the motor M continues to operate at the rated voltage, and the loom is continuously operated.

When the stop switch BS2 is operated or some cause of stoppage occurs and the relay contact K is opened, the self-holding relay R1 returns and the operation command S is released.

At the same time, the main contactor MC also returns, so the motor M immediately stops (solid line in FIG. 4). However, when the second auxiliary contactor MC2 returns, there is no abnormality signal Sa.
As long as the relay contact Sax is closed, the installation of timer TRI2 is delayed until after the fixed time tTR1 has elapsed (same).

If the main contacts of the main contactor MC are welded when starting the motor M, the release of the operation command S causes the main contactor M
Even if the excitation of C is cut off, its main contact is not opened, and therefore, the motor M at that time continues to rotate even after the stop switch BS2 is operated (as indicated by the dashed line in Fig. 4). ). At this time, without using timer TRI, the second auxiliary contactor MC2 is activated at the same time as the main contactor MC returns.
If the circuit is set up to also reset the motor M, it is possible to stop the motor M at the same time as the operation command S is released. However, in that case, the starting and stopping of the motor M from the next time onwards will be done by the first and second auxiliary contactors. This is done by MCI and MC2, and it is inevitable that these main contacts will soon be damaged. Therefore, in order to avoid such a situation, a timer TRI and a discrimination unit 1o are used.

If the main contact of the main contactor MC is welded, the terminal UVW of the motor M will not be disconnected from the three-phase power supply R3T, and at this time, the second auxiliary contactor MC2 will also be Since the return is delayed, the motor M is controlled by the operation command S as described above.
continues its rotation even after release of C, and therefore the current transformer C
T continues to output the current signal Si. The current signal Si is
The information that the driving command S has been canceled is input to the state determining means 11 of the determining unit 10, and the information that the driving command S has been canceled is input to the relay R1.
Since the information is transmitted to the timer 12 of the determination unit 10 via the normally closed contact R1b of the state determination means 1, the timer 1
After the set time t of 2 has elapsed, the magnitude of the current signal Si becomes
It is possible to detect that the value is larger than the set value set by the setting device 13 and output the abnormal signal Sa.

In this way, when the abnormality signal Sa is output, the relay contact Sax is opened, so that the second auxiliary contactor MC, 2 is immediately opened (dotted chain line in FIG. 4), and therefore, If the set time t is set as short as necessary, the motor M can be stopped quickly as in the normal state.

That is, the second auxiliary contactor MC2 at this time is
It is used as a backup switch for the main contactor MC. In addition, since the output of the abnormal signal Sa can be displayed as an appropriate alarm, the operator can
By being able to know when a welding accident (C) has occurred, and by performing appropriate repair work, it is possible to prevent the accident from spreading.

In the above explanation, the current signal Si from the current transformer CT indicates the line current of the motor M, and is used to detect the energization state of the motor M after the operation command S is canceled. It is also possible to detect the line voltage at the terminal UVW of the motor M, or to detect the rotational speed or rotational pulses of the motor M, and input this information to the determination unit 10. However, here, the rotation pulse of the motor M is, for example, a pulse signal output by a sensor installed facing the output shaft of the motor M when the output shaft is rotating.

In addition, when using the rotation speed or rotation pulse of the motor M, the setting time t of the timer 12 and the setting value of the setting device 3 should be determined appropriately, taking into consideration the speed at which the rotation speed of the motor M decreases under normal conditions. It goes without saying that it should be done. On the other hand, when using the line current or line voltage of motor M, the set time t
may be extremely short; in some cases, timer 12
It is also possible to omit.

It is assumed that the discrimination unit 10 can also be combined with other types of operating devices. That is, the present invention is applicable to the case where the motor M is directly started by only the main contactor MC, or when the main contactor MC is combined with other control elements to perform other types of overvoltage starting or reduced voltage starting. It can also be widely applied to

As for the control operation based on the abnormality signal Sa, when the second auxiliary contactor MC2 is not used, the other switches other than the main contactor MC may be opened. For example, the distribution switch inserted into the power supply side of the main contactor MC can be equipped with a shunt trip, and this can be tripped as a backup switch. A separate dedicated switch may be inserted and opened. It should be noted that the backup switch in each of these embodiments does not matter where it is inserted as long as it can be inserted in series with the main contactor MC to open and close the motor power supply.

Further, according to the present invention, since it is possible to detect that the motor M is in the energized state after the operation command S is canceled, it is possible to detect not only the welding of the main contacts of the main contactor MC but also the welding of the movable mechanism of the main contactor MC. It is also possible to deal with defects in the return operation due to sticking or the like, abnormalities in the control circuit that drives the main contactor MC, etc.

As described in detail, according to the present invention, the main contactor includes a main contactor, a backup switch, and a state determining means, and the main contactor includes:
The motor power supply is opened and closed in response to the driving command, and the state determining means outputs an abnormal signal when it detects that the motor is energized after the driving command is released, and opens the backup switch based on this. This makes it possible to reliably detect the energized state of the motor at the time when the operation command is canceled and the motor should be disconnected from the power supply as an abnormal signal, and it is possible to detect not only an abnormality in the control circuit but also a much greater This has an excellent effect in that the loom can be reliably stopped even in the event of a contact welding accident of the main contactor, which frequently occurs.

[Brief explanation of the drawing]

1 to 4 show an embodiment, in which FIGS. 1 to 4 are main circuit diagrams, FIG. 2 is a main part system diagram, FIG. 3 is a control circuit diagram, and FIG. 4 is an operation explanatory diagram. S... Operation command Sa... Abnormal signal M... Motor MC... Main contactor MCI... First auxiliary contactor MC2... Second auxiliary contactor L... Setting time 1]・・State determination means

Claims (1)

[Claims] 1) A main contactor that opens and closes the motor power supply in response to a loom operation command, a back-up switch inserted in series with the main contactor, and a energization state of the motor after the operation command is canceled. and a state determining means, the state determining means outputs an abnormal signal when it detects that the motor is in the energized state after the operation command is released, and opens the backup switch. . 2) A loom that includes a first auxiliary contactor that connects the motor windings in a delta connection and a second auxiliary contactor that connects the motor windings in a star connection, and starts the motor by switching the motor windings from the delta connection to the star connection. In the operating device, the second auxiliary contactor maintains an operating state even after the operation command is released, and the state determining means determines, based on an abnormality signal, the second auxiliary contactor as the backup switch. The loom operating device according to claim 1, wherein the loom operating device is opened. 3) The operating device for a loom according to claim 1 or 2, wherein the state determining means operates after a predetermined set time has elapsed after the operation command is released.