JP2019186077A - Power supply cutoff device - Google Patents

Abstract

To provide a power source cutoff device that can suppress the failure of a contact point drive unit due to an unstable coil voltage.SOLUTION: A power source cutoff device 2 includes a cutoff unit 21 that is connected to power supply lines PL1 to PL3 that supply power to a device 30 and that has a contact point 21a that cuts off the power supply lines PL1 to PL3, a contact point drive unit 22 that drives the contact point 21a of the cutoff unit 21 so as to cut off the power supply lines PL1 to PL3, a voltage measurement unit 50 that measures power supply voltages of the power supply lines PL1 to PL3, and a control unit 61 that controls the contact point unit 22 so as to cut off the power supply lines PL1 to PL3 when the power supply voltage measured by the voltage measurement unit 50 is less than an allowable voltage.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power shut-off device used for an injection molding machine or the like.

  Conventionally, a three-phase AC power source of 200 to 400 V is mainly used as a power source of an injection molding machine. Part of the electric power supplied from the three-phase AC power supply is converted to DC and then supplied to the control device. Another part of the electric power is supplied to the heater of the injection molding machine, for example, with alternating current. The rest of the electric power is supplied to, for example, a motor that drives each mechanism unit of the injection molding machine while maintaining an alternating current.

  The power supply line for the heater and the power supply line for the motor are provided with an electromagnetic contactor that shuts off the power supply line when an abnormality occurs. As a conventional technique related to the operation of such an electromagnetic contactor, when the temperature detecting means is disconnected from the heater or disconnected, a temperature abnormality is detected, and the electric power supply to the heater is cut off by the electromagnetic contactor. An excessive temperature rise prevention device has been proposed (see, for example, Patent Document 1).

JP 11-129309 A

  The electromagnetic contactor conducts or cuts off the power supply line by exciting or non-exciting the coil of the contact driving unit. Specifically, when the coil is excited, the movable contact and the fixed contact connected to the power supply line are electrically connected to supply power to the power supply line. On the other hand, when the coil is de-energized, the movable contact and the fixed contact are interrupted, and the supply of power to the power supply line is stopped. If the coil voltage for exciting the coil is the rated voltage or the coil voltage is sufficiently low (non-excited voltage), the movable contact can be appropriately opened and closed.

  By the way, a part of the electric power supplied to the electric power supply line is also used as electric power for exciting the coil of the contact driving unit in the electromagnetic contactor. When a phase failure or the like occurs in the power supply line, an unstable coil voltage that cannot reliably close the movable contact may be supplied to the coil. The unstable coil voltage is a voltage that is higher than the non-excitation voltage but lower than the minimum voltage necessary to close the movable contact (hereinafter also referred to as “middle coil voltage”). If the coil voltage in the intermediate region continues to be supplied to the coil, the so-called suction operation in which the coil tries to close the movable contact is repeated. For example, the coil constituting the contact drive unit overheats, so that fusing, ground fault, etc. May be a cause of failure.

  An object of the present invention is to provide a power shut-off device that can suppress a failure of a contact driving unit due to an unstable coil voltage.

(1) The present invention provides power supply lines (for example, first power supply lines PL1 to PL3 and second power supply lines PL11 to PL1, which will be described later) for supplying power to devices (for example, a heater device 30 and a motor device 40 to be described later). PL13) and a blocking part (for example, a blocking part 21 described later) having a contact (for example, a movable contact 21a described later) that blocks the power supply line, and the blocking part for blocking the power supply line. A contact driving unit (for example, a contact driving unit 22 described later) for driving the contact, a voltage measuring unit (for example, a voltage measuring unit 50 described later) for measuring a power supply voltage of the power supply line, and the voltage measuring unit When the power supply voltage measured by the above is less than the allowable voltage, a control unit (for example, a control unit to be described later) that controls the contact driving unit to cut off the power supply line 1) and relates to a power supply cutoff apparatus provided with (e.g., power cutoff device 2 to be described later).

(2) In the power shut-off device according to (1), the control unit is configured such that the power supply voltage measured by the voltage measurement unit is less than an allowable voltage (for example, an allowable voltage Vth described later) and the state is a specified time ( For example, the contact driving unit may be controlled so that the power supply line is shut off when the power supply line continues for a specified time Tth) to be described later.

(3) In the power shut-off device according to (2), a first device is connected to the power supply line, and a second device is connected to another power supply line connected in parallel to the power supply line. In the configuration, the specified time may be set for each device based on the time required for the first device and the second device to restart from power-off.

  ADVANTAGE OF THE INVENTION According to this invention, the power interruption device which can suppress the failure of the contact drive part by the unstable coil voltage can be provided.

It is a whole lineblock diagram of power supply system 1 provided with power supply cutoff device 2 of an embodiment. It is a flowchart which shows the main process sequence of the power shutdown control program performed in the control part 61 of embodiment.

  Hereinafter, embodiments of a power shutoff device according to the present invention will be described. Note that the drawings attached to this specification are schematic diagrams, and each part is represented by a functional block or the like in consideration of easy understanding.

(First embodiment)
FIG. 1 is an overall configuration diagram of a power supply system 1 including a power cutoff device 2 according to the first embodiment. The power supply system 1 of 1st Embodiment is comprised as a system which supplies an alternating current electrode to the heater and motor (after-mentioned) of an injection molding machine (not shown), for example.
As shown in FIG. 1, the power supply system 1 includes a power supply device 10, a first electromagnetic contactor 20A, a second electromagnetic contactor 20B, a heater device 30 (first device), and a motor device 40 (second device). The voltage measuring unit 50 and the control device 60 are provided. In the power supply system 1 shown in FIG. 1, the first electromagnetic contactor 20 </ b> A, the second electromagnetic contactor 20 </ b> B, the voltage measuring unit 50, and the control device 60 constitute the power cutoff device 2 in the first embodiment.

  The power supply device 10 is a three-phase AC power source that supplies three-phase AC power to a heater device 30 and a motor device 40 (described later). First power supply lines PL1, PL2, and PL3 are connected to the U, V, and W terminals on the output side of the power supply device 10, respectively. The first power supply lines PL <b> 1 to PL <b> 3 are lines that supply AC power to the heater device 30. The first power supply lines PL1 to PL3 are connected to the second power supply lines PL11, PL12, and PL13 at the connection points J1, J2, and J3, and are parallel to the second power supply lines PL11, PL12, and PL13. . The second power supply lines PL <b> 11 to PL <b> 13 are lines that supply AC power to the motor device 40.

  The first electromagnetic contactor 20 </ b> A is an electromagnetic relay device that is controlled by a control device 60 (described later) and that conducts or cuts off the first power supply lines PL <b> 1 to PL <b> 3 that supply AC power to the heater device 30. The first electromagnetic contactor 20 </ b> A includes a blocking unit 21 and a contact driving unit 22.

  The interruption | blocking part 21 is an opening / closing mechanism (main contact) comprised by the movable contact 21a, the fixed contact 21b, and the crossbar 21c. The movable contact 21a is a contact provided on the power supply side in the first power supply lines PL1 to PL3. The fixed contact 21b is a contact provided on the load side in the first power supply lines PL1 to PL3. In the interruption | blocking part 21, each movable contact 21a connected to 1st electric power supply line PL1-PL3 is connected with the contact drive part 22 via the crossbar 21c. The cross bar 21c is a member that opens and closes the three movable contacts 21a simultaneously. In addition, although the cross bar 21c is connected with the movable iron core (not shown) of the contact drive part 22, it demonstrates as a part of interruption | blocking part 21 here.

  The movable contact 21a is a contact driven by a contact drive unit 22 (described later) via the cross bar 21c. When the movable contact 21a is driven and closed by the contact driving unit 22, the movable contact 21a and the fixed contact 21b are electrically connected, and AC power is supplied from the first power supply lines PL1 to PL3 to the heater device 30. On the other hand, when the movable contact 21a is driven and opened by the contact driving unit 22, the movable contact 21a and the fixed contact 21b are disconnected, and the AC power is supplied from the first power supply lines PL1 to PL3 to the heater device 30. Stops.

The contact driving unit 22 drives the crossbar 21c by the action (electromagnetic force) of an electromagnet, and opens or closes the movable contact 21a of the blocking unit 21, thereby conducting or blocking the first power supply lines PL1 to PL3. It is.
The contact drive unit 22 includes a main coil CL1, a subcoil CL2, a movable contact 22a, a fixed contact 22b, and a crossbar 22c.

  Main coil CL1 is a member which comprises an electromagnet with a fixed iron core (not shown). The main coil CL1 is excited by applying a coil voltage to generate an electromagnetic force. When the main coil CL1 is excited, a movable iron core (not shown) arranged to face the fixed iron core is attracted to the fixed iron core against the urging force of a trip spring (not shown) by electromagnetic force. . The trip spring is a spring that biases the movable iron core in a direction away from the fixed iron core. When the movable core is sucked to the fixed core side, the cross bar 21c connected to the movable core moves to the fixed core side together with the movable core.

  When the cross bar 21c moves to the fixed iron core side, the movable contact 21a is closed at the blocking portion 21, and the movable contact 21a and the fixed contact 21b are electrically connected. Thereby, AC power is supplied to the heater device 30 from the first power supply lines PL1 to PL3. If the coil voltage for exciting the main coil CL1 is equal to or higher than an allowable voltage (described later), the movable contact 21a can be normally closed.

  On the other hand, when the main coil CL1 is de-energized, the movable iron core is not attracted by the electromagnetic force, and therefore moves to the side away from the fixed iron core by the urging force of the tripping spring. When the movable iron core moves to the side away from the fixed iron core, the cross bar 21c connected to the movable iron core returns to the position before the movement. When the cross bar 21c returns to the position before movement, the movable contact 21a is opened at the blocking portion 21, and the movable contact 21a and the fixed contact 21b are blocked. Thereby, the supply of AC power from the first power supply lines PL1 to PL3 to the heater device 30 is stopped. If the coil voltage for exciting the main coil CL1 is sufficiently low, the movable contact 21a can be normally opened.

  Electric power for exciting main coil CL1 is supplied from first electric power supply lines PL1 and PL2. First power supply lines PL1 and PL2 are connected to coil power supply lines L1 and L2 at connection points J4 and J5, respectively. The coil power supply lines L1 and L2 are lines for supplying power to the main coil CL1. The coil power supply line L1 is connected to the movable contact 22a in the contact drive unit 22. The coil power supply line L2 is connected to one end of the main coil CL1 in the contact drive unit 22. The other end of the main coil CL1 is connected to the fixed contact 22b.

  The movable contact 22a is a contact driven by the action (electromagnetic force) of an electromagnet including a sub coil CL2 (described later). When the movable contact 22a is closed, the movable contact 22a and the fixed contact 22b become conductive, and power is supplied to the main coil CL1 from the first power supply lines PL1 and PL2. On the other hand, when the movable contact 22a opens, the movable contact 22a and the fixed contact 22b are cut off, and the supply of power from the first power supply lines PL1 and PL2 to the main coil CL1 is stopped. The movable contact 22a is connected to a movable iron core (not shown) on the secondary coil CL2 side via a cross bar 22c. The cross bar 22c is a member that opens and closes the movable contact 22a.

  The subcoil CL2 is a member that constitutes an electromagnet together with a fixed iron core (not shown). The subcoil CL2 is connected to the control device 60 (described later) through the power supply line L3. The sub coil CL2 is excited by a coil voltage supplied from the control device 60, and generates an electromagnetic force. When the secondary coil CL2 is excited, a movable iron core (not shown) arranged to face the fixed iron core is attracted to the fixed iron core against the urging force of a trip spring (not shown) by electromagnetic force. . When the movable iron core is sucked to the fixed iron core side, the cross bar 22c connected to the movable iron core moves to the fixed iron core side together with the movable iron core. When the cross bar 22c moves to the fixed iron core side, the movable contact 22a is closed, and the movable contact 22a and the fixed contact 22b are electrically connected. As a result, power for excitation is supplied from the first power supply lines PL1 and PL2 to the main coil CL1.

  On the other hand, when the coil voltage is no longer supplied from the control device 60, the sub-coil CL2 is not excited. When the sub-coil CL2 is de-energized, the movable iron core is not attracted by the electromagnetic force, and therefore moves to the side away from the fixed iron core by the biasing force of the tripping spring. When the movable iron core moves to the side away from the fixed iron core, the cross bar 22c connected to the movable iron core returns to the position before the movement. When the cross bar 22c returns to the position before the movement, the movable contact 22a is opened, and the movable contact 22a and the fixed contact 22b are disconnected. As a result, power is not supplied from the first power supply lines PL1 and PL2 to the main coil CL1.

  Thus, while the coil voltage is being output from the control device 60 to the secondary coil CL2 (contact drive unit 22), the movable contact 22a and the fixed contact 22b are electrically connected, and therefore the first power supply line PL1. In addition, power for excitation is supplied from PL2 to the main coil CL1. When the main coil CL1 is excited, the movable contact 21a (interrupting part 21) is closed, and the movable contact 21a and the fixed contact 21b are electrically connected. Thereby, AC power is supplied to the heater device 30 from the first power supply lines PL1 to PL3.

  On the other hand, when the coil voltage is no longer output from the control device 60 to the sub-coil CL2 (contact drive unit 22), the movable contact 22a and the fixed contact 22b are cut off, so that the main power supply lines PL1 and PL2 can The supply of power to the coil CL1 is stopped. When the main coil CL1 is de-energized, the movable contact 21a (blocking portion 21) is opened, and the movable contact 21a and the fixed contact 21b are blocked. Thereby, AC power is not supplied from the first power supply lines PL1 to PL3 to the heater device 30.

The second electromagnetic contactor 20B is an electromagnetic relay device that is controlled by the control device 60 and conducts or cuts off the second power supply lines PL11 to PL13 that supply AC power to the motor device 40 (described later). Since the structure of the interruption | blocking part 21 and the contact drive part 22 in the 2nd electromagnetic contactor 20B is the same as 20A of 1st electromagnetic contactors, description is abbreviate | omitted.
The secondary coil CL2 of the second electromagnetic contactor 20B is connected to the control device 60 via the power line L4. The operations of the first electromagnetic contactor 20A and the second electromagnetic contactor 20B are controlled by the control device 60.

  The heater device 30 is a device that generates heat for melting a plastic as a molding material in an injection molding machine (not shown). The heater device 30 includes a heater 31 and a heater control unit 32. The heater 31 is a device used as a heat source for heating an injection part of an injection molding machine, for example. The heater control unit 32 is a device that controls the temperature of the heater 31. Each heater control unit 32 is supplied with AC power from a two-phase power supply line among the first power supply lines PL1 to PL3.

  The motor device 40 is a device that drives each mechanism of the injection molding machine. The motor device 40 includes a motor 41 and a motor control unit 42. The motor 41 is, for example, a device that is used as a power source for opening and closing the mold in the mold clamping unit. The motor control unit 42 is a device that controls the rotational speed and the like of the motor 41. AC power is supplied to the motor control unit 42 from the second power supply lines PL11 to PL13.

  The voltage measuring unit 50 is a device that measures the power supply voltage of the first power supply lines PL1 to PL3. Voltage measurement unit 50 is connected to first power supply lines PL1 to PL3 at connection points J6, J7, and J8. The connection points J6, J7, and j8 are provided on the power supply device 10 side of the first power supply lines PL1 to PL3 with respect to the connection points J1, J2, and J3 of the second power supply lines PL11 to PL13. Therefore, voltage measurement unit 50 measures the power supply voltage common to both first power supply lines PL1 to PL3 and second power supply lines PL11 to PL13. Moreover, the voltage measurement part 50 measures the power supply voltage when a phase failure occurs in the first power supply lines PL1 to PL3. The power supply voltage measured by the voltage measuring unit 50 (hereinafter also referred to as “power supply voltage Vs”) is transmitted to the control device 60.

  The control device 60 is a device that controls the operation of the first electromagnetic contactor 20A and the second electromagnetic contactor 20B based on the power supply voltage Vs measured by the voltage measuring unit 50. The control device 60 is electrically connected to the first electromagnetic contactor 20 </ b> A, the second electromagnetic contactor 20 </ b> B, and the voltage measuring unit 50 that constitute the power shutoff device 2.

The control device 60 includes a control unit 61 and a storage unit 62.
The control unit 61 includes a microprocessor unit including a CPU (Central Processing Unit), a memory, and the like. The control unit 61 implements various functions in cooperation with each hardware by executing an application program (for example, a power-off control program described later) for controlling the power-off device 2.

  When the power supply voltage Vs measured by the voltage measuring unit 50 becomes less than an allowable voltage (described later) and the state continues for a specified time Tth or longer, the control unit 61 performs first power supply lines PL1 to PL3 and PL11 to PL13 ( Hereinafter, the contact driving units 22 of the first electromagnetic contactor 20A and the second electromagnetic contactor 20B are controlled so as to cut off the generically referred to as “power supply line”. When the power supply line is conducted, the control unit 61 supplies a coil voltage to the power supply lines L3 and L4 to excite the sub coil CL2. On the other hand, when the power supply line is cut off, the control unit 61 stops the supply of the coil voltage to the power supply lines L3 and L4 and de-energizes the sub coil CL2.

  Here, the allowable voltage is a coil voltage supplied to the main coil CL1 (the first electromagnetic contactor 20A and the second electromagnetic contactor 20B), and is necessary for normally closing the movable contact 22a of the breaking part 21. Minimum voltage (hereinafter also referred to as “allowable voltage Vth”). If the power supply voltage Vs is equal to or higher than the allowable voltage Vth, the movable contact 22a can be normally closed. On the other hand, when the power supply voltage Vs is less than the allowable voltage Vth, the movable contact 22a cannot be closed normally, and the above-described suction operation may be repeated in the main coil CL1.

  The specified time Tth is a time for waiting until the power supply line is shut off after the power supply voltage Vs becomes less than the allowable voltage Vth. Unlike the case where an abnormality such as a phase failure occurs in the power supply line when the power supply voltage Vs becomes less than the allowable voltage Vth due to a momentary power failure (for example, several 100 ms or less) in the factory. In most cases, it is not necessary to stop the operation of the injection molding machine. If the power supply line is interrupted each time such an event occurs, the injection molding machine stops despite the fact that it cannot be regarded as abnormal, so that restarting takes time and productivity is reduced. Therefore, after the power supply voltage Vs becomes less than the allowable voltage Vth, the unintentional stop of the injection molding machine can be suppressed by cutting off the power supply line when the state continues for the specified time Tth or longer. As a specific example of the specified time Tth, for example, 1 s or less can be cited. In the control unit 61, the specified time Tth is managed by a timer control program executed by the control unit 61.

  The storage unit 62 is a storage device that stores various programs, data, and the like executed by the control unit 61. The storage unit 62 is configured by, for example, a semiconductor memory, a hard disk device, or the like. The storage unit 62 stores, for example, a power-off control program as an application program.

Next, the processing content of the power-off control program executed in the control unit 61 (control device 60) of the first embodiment will be described based on the flowchart shown in FIG.
FIG. 2 is a flowchart illustrating a processing procedure of a power shutdown control program executed in the control unit 61 of the first embodiment.

In step S101 in FIG. 2, the control unit 61 resets the timer (Ts = 0). The operation of the timer is managed by the timer control program as a subroutine of the power-off control program.
In step S102, the control unit 61 determines whether or not the elapsed time Ts of the timer has reached the specified time Tth. In step S102, when the controller 61 determines that the elapsed time Ts of the timer has reached the specified time Tth (YES), the process proceeds to step S105. On the other hand, if the controller 61 determines that the elapsed time Ts of the timer has not reached the specified time Tth (NO), the process proceeds to step S103.

Here, a case will be described in which it is determined that the elapsed time Ts of the timer has not reached the specified time Tth.
In step S103 (step S102: NO), the control unit 61 acquires the power supply voltage Vs measured by the voltage measurement unit 50.

  In step S104, the control unit 61 determines whether or not the power supply voltage Vs is equal to or higher than the allowable voltage Vth. If the control unit 61 determines in step S104 that the power supply voltage Vs is less than the allowable voltage Vth (YES), the process proceeds to step S102. If it is determined in step S104 that the power supply voltage Vs is less than the allowable voltage Vth, an abnormality such as a phase failure may have occurred in the power supply line. In step S102, the elapsed time Ts of the timer is set to the specified time Tth. It will be in a standby state until it determines with having reached.

  On the other hand, when the control unit 61 determines in step S104 that the power supply voltage Vs is equal to or higher than the allowable voltage Vth (NO), the process proceeds to step S101. When it is determined that the power supply voltage Vs is equal to or higher than the allowable voltage Vth, it is considered that an abnormality such as a phase failure has not occurred in the power supply line, and thus the process returns to step S101 to reset the time count of the timer.

  If the determination in step S104 is YES (YES), the process proceeds to step S102, and it is determined in step S104 that the power supply voltage Vs is equal to or higher than the allowable voltage Vth before the timer elapsed time Ts reaches the specified time Tth. Since the power supply voltage Vs is considered to have dropped instantaneously, the process returns to step S101 to reset the timer timing.

  On the other hand, in step S105 (step S102: YES), the control unit 61 supplies power so as to shut off the first power supply lines PL1 to PL3 and PL11 to PL13 by the first electromagnetic contactor 20A and the second electromagnetic contactor 20B. The supply of the coil voltage to the lines L3 and L4 is stopped. In step S105, after cutting off the power supply line, the process of this flowchart ends (returns to step S101).

  In the power shutoff device 2 of the first embodiment described above, the control unit 61 supplies power to the first electromagnetic contactor 20A and the second electromagnetic contactor 20B when the power supply voltage Vs of the power supply line becomes less than the allowable voltage Vth. The contact driving unit 22 is controlled so as to cut off the power supply line that supplies the power. Therefore, in the power shutoff device 2 of the first embodiment, it is possible to suppress a failure of each contact driving unit 22 of the first electromagnetic contactor 20A and the second electromagnetic contactor 20B due to an unstable coil voltage.

  Further, in the power shutoff device 2 of the first embodiment, the control unit 61 shuts off the power supply line when the state where the power supply voltage Vs of the power supply line is less than the allowable voltage Vth continues for a specified time Tth or longer. Next, the contact driving unit 22 is controlled. According to this, since the power shut-off device 2 of the first embodiment does not stop the injection molding machine carelessly in a situation where it cannot be regarded as abnormal, it is possible to suppress a decrease in productivity.

(Second Embodiment)
In the power shut-off device 2 of the second embodiment, the control unit 61 is different from the first embodiment in that the control unit 61 individually executes the processing of the power shut-off control program shown in FIG. 2 for the heater device 30 and the motor device 40. Is different. In addition, since the basic configuration of the power shutoff device 2 in the second embodiment is the same as that of the first embodiment, the second embodiment will be described with reference to the drawing of the first embodiment. Moreover, in description of 2nd Embodiment, the member etc. equivalent to 1st Embodiment are demonstrated using the same code | symbol as 1st Embodiment.

  In the first embodiment, when the state where the power supply voltage Vs of the power supply line is less than the allowable voltage Vth continues for a specified time Tth or longer, the two power supply lines (PL1 to PL3 and PL11 to PL13) are simultaneously cut off. An example has been described, but is not limited to this. The specified time Tth may be set to a different time depending on the devices to be connected (in this example, the heater device 30 and the motor device 40). For example, in the heater device 30, when the first power supply lines PL1 to PL3 are shut off, the temperature of the injection unit decreases, and even after restarting, reaches a predetermined temperature and becomes ready for a molding operation. It takes time. Therefore, in the heater device 30, the specified time Tth may be slightly longer than 1 s so as to avoid the interruption of the first power supply lines PL1 to PL3 as much as possible. This is because several tens of minutes are required for the main coil CL1 (first electromagnetic contactor 20A) to fail due to repeated suction operations. On the other hand, since the motor device 40 does not take time to restart after the second power supply lines PL11 to PL13 are shut off, the specified time Tth may be slightly shorter than 1s or 1s.

  The control part 61 (control apparatus 60) of 2nd Embodiment performs the process of the power-off control program shown in FIG. 2 separately about the heater apparatus 30 and the motor apparatus 40, respectively. At this time, when the power supply voltage Vs becomes less than the allowable voltage Vth, the specified time Tth is set to a different time. For example, for the first power supply lines PL <b> 1 to PL <b> 3 that supply AC power to the heater device 30, the second power supply that supplies AC power to the motor device 40 by setting the specified time Tth to a range from 1 s to several s. For the lines PL11 to PL13, the specified time Tth is set to less than 1 s. In this way, by setting the specified time Tth to a different time depending on the connected equipment, the power supply line can be shut off according to the characteristics of the equipment, so that the production efficiency of the injection molding machine can be further increased. .

  As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above, Various deformation | transformation and a change are possible like the deformation | transformation form mentioned later, These are also this invention. Within the technical scope of In addition, the effects described in the embodiments are merely a list of the most preferable effects resulting from the present invention, and are not limited to those described in the embodiments. In addition, although the above-mentioned embodiment and the deformation | transformation form mentioned later can also be used in combination suitably, detailed description is abbreviate | omitted.

(Deformation)
In the embodiment, the example in which the power supply line is shut off when the state where the power supply voltage Vs of the power supply line is less than the allowable voltage Vth continues for the specified time Tth has been described, but the present invention is not limited to this. In the case where only one electromagnetic contactor is connected to the power supply line, the power supply line may be shut off immediately after the power supply voltage Vs becomes less than the allowable voltage.

  In the embodiment, the heater device 30 and the motor device 40 have been described as devices connected to the power supply line. However, the number of devices connected to the power supply line may be one, or three or more. There may be. Further, the specified time Tth may be set in advance.

  DESCRIPTION OF SYMBOLS 1: Power supply system, 2: Power supply interruption | blocking apparatus, 10: Power supply apparatus, 20A: 1st electromagnetic contactor, 20B: 2nd electromagnetic contactor, 21: interruption | blocking part, 21a: Movable contact (contact), 22: Contact drive 30: heater device, 40: motor device, 50: voltage measurement unit, 60: control device, 61: control unit, 62: storage unit, CL1: main coil, CL2: subcoil, L1, L2: coil power supply line , L3, L4: power line, PL1-PL3: first power supply line (power supply line), PL11-PL13: second power supply line (power supply line)

Claims (3)

A blocking unit connected to a power supply line for supplying power to the device and having a contact for blocking the power supply line;
A contact driving unit that drives the contact of the blocking unit to block the power supply line;
A voltage measuring unit for measuring a power supply voltage of the power supply line;
When the power supply voltage measured by the voltage measurement unit is less than an allowable voltage, a control unit that controls the contact driving unit to cut off the power supply line;
A power shut-off device comprising:   The said control part controls the said contact drive part so that the said electric power supply line may be interrupted | blocked, when the power supply voltage measured by the said voltage measurement part becomes less than an allowable voltage, and the state continues more than regulation time. The power shut-off device according to 1.   In the configuration in which the first device is connected to the power supply line and the second device is connected to another power supply line connected in parallel to the power supply line, the first device and the second device The power cutoff device according to claim 2, wherein the specified time is set for each device based on a time required for the device to restart from the power cutoff.

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