JP6992784B2 - Passenger conveyor - Google Patents

Description

The present invention relates to a passenger conveyor.

Patent Document 1 discloses that a fuse is blown or a circuit breaker is operated when a ground fault occurs on a passenger conveyor.

Japanese Unexamined Patent Publication No. 54-082615

An object of the present invention is to enable a ground fault in a safety circuit to be appropriately cut off by an overcurrent circuit breaker in a configuration in which a DC power supply is used as a control power source for the safety circuit of a passenger conveyor.

The passenger conveyor of the present invention
It is a passenger conveyor that circulates and drives the steps connected in an endless manner.
A safety circuit including a safety device for detecting an abnormality in the passenger conveyor and a safety device monitor relay for detecting the operating state of the safety device.
A DC power supply that outputs DC current to the safety circuit,
Equipped with an overcurrent circuit breaker,
The overcurrent circuit breaker, the contact of the safety device, and the safety device monitor relay are connected in series in this order between the positive and negative output terminals of the DC power supply.
The negative output terminal of the DC power supply is grounded,
The overload stop current value of the DC power supply device is larger than the instantaneous trip current value of the overcurrent circuit breaker.

According to the present invention, in a configuration in which a DC power source is used as a control power source for a safety circuit of a passenger conveyor, a ground fault in the safety circuit can be appropriately cut off by an overcurrent circuit breaker.

It is a schematic side view of the escalator in Embodiment 1. FIG. It is a figure which showed the electric structure of the safety circuit of the escalator in Embodiment 1. FIG. It is a figure which showed the circuit structure of the DC power supply device of the escalator in Embodiment 1. FIG. It is a figure explaining the operation of the escalator in Embodiment 1. It is a figure which showed the electric structure of the safety circuit of the escalator in the comparative example 1. FIG. It is a figure which showed the electric structure of the safety circuit of the escalator in the comparative example 2.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Background of invention)
The background of the invention will be described first. Conventionally, an AC power supply or a DC power supply has been used as a control power supply for a safety circuit including a safety device for detecting an abnormality in an escalator. If an AC power supply is used as the control power supply for the safety circuit, the earth-leakage circuit breaker can easily cut off the ground fault when the ground fault occurs in the safety circuit. However, if an AC power source is used as a control power source for the safety circuit, the durability of the contacts of the safety device included in the safety circuit may be adversely affected. On the other hand, if a DC power supply is used as a control power supply for a safety circuit, adverse effects on the durability of the contacts of the safety device can be suppressed, but an earth-leakage circuit breaker suitable for DC has not become widespread.

In view of the above, the present invention makes it possible to appropriately cut off a ground fault in a safety circuit in a configuration in which a DC power supply is used as a control power source for the safety circuit of a passenger conveyor.

(Embodiment 1)
1. 1. Configuration Figure 1 is a schematic side view of the escalator according to the first embodiment. The escalator 1 is an example of a passenger conveyor.

The escalator 1 includes an escalator main body 10, a motor 20, an inverter 30, a programmable logic controller 40 (hereinafter referred to as "PLC40"), and the like.

The escalator main body 10 is installed in a state of being bridged between two floors F1 and F2 of the building. The escalator main body 10 includes a plurality of steps 11 connected in an endless manner, a pair of left and right endless handrails 12, a power transmission mechanism for transmitting the power of the motor 20 to the steps 11 and the handrail 12, and a riding port 5. It also has a floor plate 19 or the like that constitutes the floor surface of the exit 6. The plurality of steps 11 and the handrail 12 are circulated and driven by the power of the motor 20 driven by the electric power supplied from the inverter 30. The PLC 40 controls the operation of the escalator 1. In the escalator 1 of the present embodiment, it is assumed that the floor F1 is provided with the entrance 5 and the floor F2 is provided with the exit 6, but in the present invention, the floor F2 is provided with the entrance 5. An exit may be provided on the floor F1.

The inverter 30 inputs AC power, converts the frequency of the input AC power, and supplies it to the motor 20.

The motor 20 operates at a rotation speed corresponding to the frequency of the AC power supplied from the inverter 30. As a result, the drive speed of the step 11 is changed according to the frequency of the AC power supplied from the inverter 30. The motor 20 is composed of, for example, an induction motor.

The PLC 40 has a control unit, a storage unit, and an input / output interface. The storage unit is composed of, for example, a flash memory, and stores a program and various data. The control unit is composed of, for example, a CPU, an MPU, or the like, reads a program and data from a storage unit, and performs arithmetic processing based on the read program and data. As a result, various functions in the PLC 40 are realized. The input / output interface is an interface for inputting / outputting signals to / from various devices connected to the PLC 40, and performs signal format conversion and the like. The control device that controls the escalator 1 may be configured by using a general-purpose computer instead of the PLC40. Further, the control device may be composed only of hardware such as an electronic circuit and a relay sequence circuit.

FIG. 2 is a block diagram showing an electrical configuration of the safety circuit and the like of the escalator 1 in the first embodiment.

The escalator 1 includes a safety circuit 50 including safety devices 51, 52, 53, 54 and a safety device monitor relay 55, a DC power supply device 60, and an overcurrent circuit breaker 70.

The DC power supply device 60 outputs a DC current to the safety circuit 50. The DC power supply device 60 inputs an AC voltage, converts the input AC voltage into a DC voltage, and outputs the input between the positive and negative output terminals C + and C-. The AC voltage is, for example, AC200V, and the DC voltage is, for example, DC24V.

Each of the safety devices 51, 52, 53, 54 detects various abnormalities relating to the escalator 1. The safety devices 51, 52, 53, 54 are, for example, an inlet guard safety device, a step abnormality traveling detection device, a skirt guard safety device, a handrail speed abnormality detection device, and the like. Each of the safety devices 51, 52, 53, 54 has a contact that closes in normal times and opens when an abnormality occurs.

The safety device monitor relay 55 detects the operating state of the safety devices 51, 52, 53, 54. The safety device monitor relay 55 has a make contact (not shown) that closes when the excitation coil is energized (excitation voltage is applied) and opens when the excitation coil is not energized (excitation voltage is applied). The open / closed state of this contact is monitored by a PLC 40, a relay type control circuit (not shown), or the like.

The overcurrent circuit breaker 70 instantly performs an opening operation (instantaneous disconnection operation) (trips) when a current having a value larger than the instantaneous disconnection current value flows in. As a result, the overcurrent circuit breaker 70 cuts off the current supply from the DC power supply device 60 to the safety circuit 50.

The overcurrent circuit breaker 70, the contacts of the safety devices 51, 52, 53, 54, and the safety device monitor relay 55 are connected in series in this order between the positive and negative output terminals C + and C- of the DC power supply device 60. Has been done. Further, the negative output terminal C- of the DC power supply device 60 is grounded.

When an abnormality is detected in any of the safety devices 51, 52, 53, 54, the contact of the safety device that detected the abnormality is opened, and the exciting coil of the safety device monitor relay 55 is not energized (excitation voltage is not applied). ). As a result, the contacts of the safety device monitor relay 55 are opened. When the contact of the safety device monitor relay 55 is opened, the PLC 40 and the relay type control circuit perform control to stop the drive of the motor 20 and control to engage the brake (not shown).

FIG. 3 is a diagram showing a circuit configuration of the DC power supply device 60 of the escalator 1 according to the first embodiment.

The DC power supply device 60 is provided on the output side of a rectifying unit 61 that converts (rectifies) the input AC voltage into a DC voltage, a smoothing capacitor 62 that smoothes the DC voltage rectified by the rectifying unit 61, and a smoothing capacitor 62. The semiconductor switch 63 (semiconductor element), the shunt 64 that outputs a signal according to the magnitude of the output current, and the controller 65 are provided.

The controller 65 controls ON / OFF of the semiconductor switch 63 based on the signal output from the shunt 64. Specifically, the controller 65 keeps the semiconductor switch 63 ON when the output current value indicated by the signal output from the shunt 64 during the operation of the DC power supply device 60 is equal to or less than the overload stop current value, and the DC power supply The operation of the device 60 is continued. The overload stop current value is set according to the rated output current value or the like in order to protect the DC power supply device 60 from the overload. When the output current value exceeds the overload stop current value, the controller 65 instantly controls the semiconductor switch 63 to OFF, and stops the operation of the DC power supply device 60. At this time, since the coil of the safety device monitor relay 55 is not energized, the contacts of the safety device monitor relay 55 are opened, and the PLC 40 and the relay type control circuit control the drive of the motor 20 to be stopped and the brake to be engaged. It will be. After controlling the semiconductor switch 63 to OFF, the controller 65 controls the semiconductor switch 63 to ON when the administrator of the escalator 1 performs an escalator activation operation on the key switch or the like and an ON signal is output from the PLC 40. Then, the output of the DC current is restarted.

In the present embodiment, when a ground fault occurs in the safety circuit 50, the overcurrent circuit breaker 70 performs an instantaneous disconnection operation (instantaneous interruption operation) before the DC power supply device 60 stops due to an overload. The following conditions are provided for the DC power supply device 60 and the overcurrent circuit breaker 70.
Overload stop current value of DC power supply device 60> Instantaneous disconnection current value of overcurrent circuit breaker 70

2. 2. Operation FIG. 4 is a diagram illustrating the operation of the escalator 1 in the first embodiment.

As illustrated in FIG. 4, it is assumed that a ground fault has occurred in the power line between the safety device 52 and the safety device 53. In the escalator 1 of the present embodiment, the overload stop current value of the DC power supply device 60 is larger than the instantaneous disconnection current value of the overcurrent circuit breaker 70. Therefore, when a ground fault occurs, the DC current value output from the DC power supply device 60 reaches the instantaneous tripping current value of the overcurrent circuit breaker 70 before it reaches the overload stop current value. Then, when the DC current value output from the DC power supply device 60 reaches the instantaneous disconnection current value of the overcurrent circuit breaker 70, the overcurrent circuit breaker 70 instantly trips (performs the instantaneous disconnection operation). As described above, according to the present embodiment, when a ground fault occurs in the safety circuit 50, the overcurrent circuit breaker 70 is tripped before the DC power supply device 60 stops overloading, which causes the ground fault. The safety circuit 50 that has become can be appropriately cut off.

Here, in the present embodiment, the DC power supply device 60 stops the output of the DC current when the output current value exceeds the overload stop current value, and restarts the output of the DC current when the start operation for the escalator 1 is performed. It is configured to do. This is so that the escalator 1 can be easily restarted when the number of passengers temporarily becomes extremely large and the escalator 1 is stopped due to an overload. In the case of having such a configuration, contrary to the present embodiment, the overload stop current value of the DC power supply device is smaller than the instantaneous trip current value of the overcurrent circuit breaker. Then, when a ground fault occurs, the DC power supply will stop due to overload before the overcurrent circuit breaker trips. If the overcurrent circuit breaker is not tripped, the escalator administrator may easily start it without investigating the cause, and if the degree of ground fault is mild, the escalator will start normally. There is a possibility that it will be done. As a result, the escalator manager may overlook the occurrence of ground faults. However, in the present embodiment, as described above, the overload stop current value of the DC power supply device 60 is set to be larger than the instantaneous disconnection current value of the overcurrent circuit breaker 70, so that the DC power supply device is set when a ground fault occurs. The overcurrent circuit breaker 70 trips first before the 60 stops due to overload. Therefore, it is highly possible that the escalator manager tries to find out the cause of the trip of the overcurrent circuit breaker 70 and discovers the occurrence of a ground fault.

FIG. 5 is a diagram showing an electrical configuration of the safety circuit and the like of the escalator in Comparative Example 1.

In Comparative Example 1, the negative output terminal C-side of the DC power supply device 60 is grounded via the resistor 80. In this case, the ground fault current becomes smaller due to the presence of the resistance 80. As a result, the magnitude of the current passing through the overcurrent circuit breaker 70 at the time of a ground fault becomes smaller than the instantaneous tripping current value (for example, 5 (A) above), and the overcurrent circuit breaker 70 at the momentary ground fault. Has the problem that it does not work.

FIG. 6 is a diagram showing an electrical configuration of an escalator safety circuit and the like in Comparative Example 2.

In Comparative Example 2, the control power supply is composed of an AC power supply. Therefore, an isolation transformer 90 is provided in place of the DC power supply device 60. Further, an earth-leakage circuit breaker 70A is provided as a circuit breaker. If the circuit breaker is an earth-leakage circuit breaker 70A, the safety circuit can be appropriately disconnected by the earth-leakage circuit breaker 70A even when the ground fault current is minute. However, if an AC power supply is used, the durability of the contacts of the safety devices 51 to 54 may be adversely affected. In addition, a control circuit that uses an AC power supply and a control circuit that uses a DC power supply coexist, and there is a risk of contact.

(Summary of embodiments)
(1) The escalator 1 (an example of a passenger conveyor) of the first embodiment is
An escalator 1 that circulates and drives a step 11 connected in an endless manner.
A safety circuit 50 including safety devices 51, 52, 53, 54 for detecting an abnormality in the escalator 1 and a safety device monitor relay 55 for detecting the operating state of the safety devices 51, 52, 53, 54.
A DC power supply device 60 that outputs a DC current to the safety circuit 50,
Equipped with an overcurrent circuit breaker 70,
The overcurrent circuit breaker 70, the contacts of the safety devices 51, 52, 53, 54, and the safety device monitor relay 55 are connected in series in this order between the positive and negative output terminals C + and C- of the DC power supply device 60. ,
The negative output terminal C- of the DC power supply device 60 is grounded.
The overload stop current value of the DC power supply device 60 is larger than the instantaneous disconnection current value of the overcurrent circuit breaker 70.

According to this configuration, in a configuration in which a DC power supply is used as a control power source for the safety circuit 50 of the escalator 1, the ground fault in the safety circuit 50 can be appropriately cut off by the overcurrent circuit breaker 70.

(2) In the escalator 1 of the first embodiment
The DC power supply device 60 resumes the output of the DC current when the start operation for the escalator 1 is performed after the output of the DC current is stopped due to the overload.

Even with such a configuration, the trip of the overcurrent circuit breaker 70 due to the configuration of (1) increases the possibility that the escalator manager will find a ground fault in the safety circuit 50.

(Other embodiments)
(A)
The escalator 1 of the above embodiment is an example of the passenger conveyor of the present invention. In the present invention, the passenger conveyor may be a passenger conveyor such as a so-called moving walkway arranged horizontally or diagonally on one floor.

1 Escalator 5 Entrance 6 Exit 10 Escalator body 11 Step 12 Handrail 19 Floor plate 20 Motor 30 Inverter 40 PLC
50 Safety circuit 51 to 54 Safety device 55 Safety device Monitor relay 60 DC power supply device 61 Rectifier 62 Smoothing capacitor 63 Semiconductor switch 64 Shunt 65 Controller 70 Overcurrent circuit breaker F1 Floor F2 Floor

Claims (2)

It is a passenger conveyor that circulates and drives the steps connected in an endless manner.
A safety circuit including a safety device for detecting an abnormality in the passenger conveyor and a safety device monitor relay for detecting the operating state of the safety device.
A DC power supply that outputs a DC current to the safety circuit,
Equipped with an overcurrent circuit breaker,
The overcurrent circuit breaker, the contact of the safety device, and the safety device monitor relay are connected in series in this order between the positive and negative output terminals of the DC power supply device.
The negative output terminal of the DC power supply is grounded,
The overcurrent circuit breaker is configured to perform an instantaneous disconnection operation when the DC current value output from the DC power supply device reaches the instantaneous disconnection current value.
The DC power supply device is configured to stop due to overload when the output DC current value exceeds the overload stop current value.
When a ground fault occurs in the safety circuit, the overload stop current value of the DC power supply device is set so that the overcurrent circuit breaker momentarily disconnects before the DC power supply device stops due to overload. , The value is set to be larger than the instantaneous disconnection current value of the overcurrent circuit breaker.
Passenger conveyor. The DC power supply device resumes the output of the DC current when the passenger conveyor is started after the output of the DC current is stopped due to an overload.
The passenger conveyor according to claim 1.

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