JPH05294576A - Maintenance and safety device for linear elevator - Google Patents

Abstract

PURPOSE:To safely and easily carry out a maintenance service work for fastening terminal screws in a connection part between a linear motor for a linear elevator and a power cable, and so forth with a single service crew. CONSTITUTION:An elevator cage is moved so as to establish a predetermined positional relationship between the elevator cage and a balance weight, and during maintenance and inspection service for the connection between a linear motor installed on the balance weight and the power cable, a contractor 21 is opened by an upper switch 22 provided in the upper part of the cage, and an output path from an invertor 14 for driving the linear motor is isolated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a maintenance and safety device for a linear elevator, and more particularly, to safely perform maintenance work such as retightening of motor terminal screws in a linear elevator having a linear motor mounted on a counterweight. The present invention relates to a maintenance safety device for.

[0002]

2. Description of the Related Art A technique disclosed in Japanese Patent Application Laid-Open No. 1-271381 can be cited as one related to a conventional linear elevator of this type. However, in the above-mentioned publication, power supply to the linear motor is realized by using a trolley mechanism, but since there is no functional difference even if a cable is used, the cable power supply system will be described as a premise.

FIG. 5 is a front view showing a state during maintenance work of a conventional linear elevator. In the figure, 1 is an elevator car, 2 is a counterweight, and 3 is a linear motor mounted on the counterweight 2. 4 is a wire rope that connects the elevator car 1 and the counterweight 2, 5a and 5b are pulleys that suspend the elevator car 1 and the counterweight 2 via the wire rope 4, and 6 is pulleys 5a and 5b. It is a ceiling beam of a fixed building. 7 is a secondary conductor arranged over the entire length of the hoistway, 8 is a power cable for supplying electric power to the linear motor 3, 9 is the power cable 8 fixed to the counterweight 2, and the counterweight 2 Linear motor 3 installed in
This is a connection portion that internally houses a terminal for connecting to the lead wire of the above, and a terminal by screwing is usually used. 1
Reference numeral 0 denotes a maintenance worker, and FIG. 5 shows a state in which the connection portion 9 is maintained on the ceiling of the elevator car 1.

FIG. 6 is a front view taken along the line AA of FIG. 5, in which the same reference numerals and symbols as those in FIG. 5 denote the same or corresponding components as those of FIG. In the figure, 3a
3f is a linear motor mounted on the counterweight 2, 11
Is a core wire of the power cable 8, and each linear motor 3a ...
Each of the lead wires 3f is connected to the core wire 11 of the power cable 8 at the connecting portion 9 for each of the three phases U, V, W.

FIG. 7 is a circuit diagram showing a main circuit of a conventional maintenance safety device for a linear elevator. In the figure, 8 is the same power cable as in FIGS. 5 and 6, 12 is a contactor for turning on and off three-phase alternating current, 13 is a diode bridge for rectification that is connected to the contactor 12 and converts alternating current into direct current, and 14 is An electrolytic capacitor for smoothing the direct current converted by the diode bridge 13 into a stable direct current power source, and 15 is an inverter for converting direct current into alternating current of an arbitrary frequency.
5 shows an example in which No. 5 is configured. 16 is a transformer, 17
Is a diode bridge that rectifies the output of the transformer 16,
Reference numeral 18 is a charging resistor for limiting the current charged in the electrolytic capacitor 14.

In the linear elevator having this structure, when the power of the elevator is turned on, the electrolytic capacitor 14 is charged by the charging circuit including the transformer 16, the diode bridge 17 and the charging resistor 18 shown in FIG. After the electrolytic capacitor 14 is completely charged, the contactor 12 is turned on based on the elevator start-up command to drive the inverter 15. The three-phase AC current supplied from the inverter 15 is shunted to the linear motors 3a to 3f at the connecting portion 9 through the power cable 8. Linear motor 3
The current supplied to a to 3f generates a three-phase moving magnetic field,
A voltage is induced in the secondary conductor 7. A current flows through the secondary conductor 7 due to the induced voltage, and the counterweight 2 moves up and down by an electromagnetic force generated between the current and the moving magnetic field. In response to this, the elevator car 1 connected by the wire rope 4 moves up and down synchronously.

[0007]

In the conventional linear elevator having the above-mentioned structure, the terminal screw of the connecting portion 9 between the power cable 8 and the linear motors 3, 3a to 3f is loosened, and the screw is regularly tightened. Had to do. When the maintenance work of this linear elevator is performed by one person, the maintenance worker 10 rides on the ceiling of the elevator car 1 and moves the elevator car 1 to a position facing the connecting portion 9 to connect the elevator car 1 while the elevator operation is stopped. The terminal screw of the portion 9 was retightened.

However, during such maintenance work, the contactor 1
Although 2 is cut off and the inverter 15 and the power supply are cut off, the charging circuit is not cut off, and a high voltage (for example, about 300 V DC in the case of 200 V AC power supply) is applied to the electrolytic capacitor 14. It was in a state of being stuck. Therefore, in this state, only the inverter 15 cuts off the voltage of the electrolytic capacitor 14, and it cannot be said that it is necessarily safe considering the leakage current. Also, the connecting portion 9
If the elevator start button is pressed by mistake during the tightening work of the terminal screw, the contactor 12 enters and the inverter 15 operates, so that the maintenance worker 10 has a high risk of electric shock. Further, there is a possibility that a short circuit may occur between the terminals due to a tightening tool or the like, causing a short circuit accident of the output of the inverter 15 and leading to a serious accident such as a fire.

In order to prevent these, it is sufficient to go to the place where the inverter 15 is installed and turn off the power before performing the tightening work, but the work efficiency was very poor. Further, when the facing position of the elevator car 1 and the connecting portion 9 is apart from the elevator hall, the maintenance worker 10 could not go out to the elevator hall and could not turn off the power.
If two workers perform maintenance work, one can turn off the power and the other can perform tightening work to secure safety, but on the elevator car 1 and machine room (installation of the inverter 15). It is generally difficult to contact the location), and there was a possibility that the power might be accidentally turned on during tightening work due to incomplete contact.

Therefore, an object of the present invention is to provide a maintenance / safety device for a linear elevator, in which even one maintenance worker can safely and easily perform maintenance work such as tightening the terminal screw of the connection portion. ..

[0011]

A maintenance safety device for a linear elevator according to the present invention includes a counterweight connected to an elevator car via a wire rope and moving up and down along a secondary conductor in a hoistway. A connecting portion between a linear motor and a power cable that enables maintenance and inspection work by placing a linear motor mounted on a counterweight and driven by an inverter and the elevator car and the counterweight in a predetermined positional relationship. And a switch that is disposed above the elevator car and that can cut off the output path of the inverter.

[0012]

In the maintenance safety device for a linear elevator according to the present invention, maintenance and inspection work is performed on the connection portion between the linear motor mounted on the counterweight and the power cable with the elevator car and the counterweight having a predetermined positional relationship. At this time, because the switch provided on the upper part of the elevator car cuts off the output path of the inverter that drives the linear motor,
When performing such maintenance work, one operator can disconnect the inverter from the power supply and linear motor, and even if the elevator start button is accidentally pressed during maintenance work, the inverter will not operate, and the maintenance worker There is no risk of electric shock.

[0013]

Embodiments of the present invention will be described below. <First Embodiment> FIG. 1 is a circuit diagram showing a main circuit of a maintenance safety device for a linear elevator according to a first embodiment of the present invention, FIG.
FIG. 1 is a circuit diagram showing a contactor control circuit of a maintenance safety device for a linear elevator that is a first embodiment of the present invention. Note that FIGS. 5 and 6 are common to the conventional example, and the description thereof is omitted here. In the figure, the same reference numerals and symbols as those of the above-mentioned conventional example indicate the same or corresponding components as those of the above-mentioned conventional example.

In the figure, 21 is a contactor that disconnects the power cable 8 and the output of the inverter 15, and FIG. 1 shows the main contact of the contactor 21. 21a is a contactor 2
1 is an auxiliary contact, 22 is an on-car switch disposed on the ceiling of the elevator car 1, 23 is an auxiliary contact of the contactor 12, 24 is a coil of the contactor 21, and 25 is a coil of the contactor 12.

Next, the operation of the maintenance safety device for the linear elevator of this embodiment will be described. Also in this embodiment, similarly to the conventional example, the power cable 8 and the linear motor 3a are used.
In order to tighten the terminal screw of the connection part 9 with 3f, the maintenance worker 10 rides on the ceiling of the elevator car 1 and moves the elevator car 1 to a position facing the connection part 9 to stop the terminal while the elevator is stopped. Tighten the screws. Before entering the tightening work, the elevator car 1 in which the maintenance worker 10 is stopped
When the on-car switch 22 is operated to the shut-off state, the contactor 12 is in the open state because the elevator is not in operation and the auxiliary contact 23 is also open, so the coil 24 is deenergized and the contactor 21 is opened. .. Therefore, the inverter 15 and the power cable 8 are electrically disconnected, and no voltage is applied to the motor terminal of the connecting portion 9. Thus, while the contactor 21 is open, the coil 25 of the contactor 12 is forcibly maintained in the deenergized state by the auxiliary contact 21a, and the power supply is not connected even if the elevator is accidentally started. On the contrary, while the elevator is normally operating and the inverter 15 is operating, the auxiliary contact 23 of the contactor 12 short-circuits the car upper switch 22 and the contact failure of the car upper switch 22 causes the inverter 15 to move during traveling.
The output of is blocked.

As described above, the maintenance safety device for the linear elevator according to the present embodiment is connected to the elevator car 1 via the wire rope 4 and the counterweight 2 that moves up and down in the hoistway along the secondary conductor 7. , The elevator car 1 and the counterweight 2 which are mounted on the counterweight 2 and driven by an inverter 15.
Linear motors 3, 3a to 3f for moving up and down, and the elevator car 1 by moving the elevator car 1 and the counterweight 2
The linear motors 3, 3a to 3a, which allow maintenance and inspection work such as retightening of terminal screws, by placing and in a predetermined positional relationship.
It is provided with a connecting portion 9 between the f and the power cable 8 and an on-car switch 22 which is arranged above the elevator car 1 and which can shut off the contactor 21 in the output path of the inverter 15.

That is, in the maintenance safety device for a linear elevator according to the present embodiment, the elevator car 1 is moved to bring the elevator car 1 and the counterweight 2 into a predetermined positional relationship, and the linear car mounted on the counterweight 2 is mounted. When performing maintenance work on the connection 9 between the motors 3, 3a to 3f and the power cable 8, the contactor 21 is opened by the on-car switch 22 provided on the upper part of the elevator car 1, and the linear motors 3 and 3a to. The output path of the inverter 15 that drives 3f is cut off.

Therefore, when performing such maintenance work, it is not necessary to bother to go to the installation place of the inverter 15 in order to turn off the power supply before the work, and one worker can operate the inverter 15, the power supply and the linear motors 3, 3a. Since it can be disconnected from 3f, even if the elevator start button is pressed by mistake during maintenance work, the inverter 15 does not operate, and fire or the like due to a short circuit accident of the output of the inverter 15 does not occur, and the maintenance worker 10 receives an electric shock. There is no fear. As a result, one maintenance worker 10 can easily and safely perform maintenance work such as tightening the terminal screws of the connection portion 9 between the power cable 8 and the linear motors 3, 3a to 3f.

<Second Embodiment> FIG. 3 is a circuit diagram showing a main circuit of a maintenance safety device for a linear elevator according to a second embodiment of the present invention. It should be noted that FIGS. 2, 5 and 6 are common to the conventional example and the first embodiment, and therefore the description thereof is omitted here.
In the figure, the same reference numerals and symbols as those of the above-mentioned conventional example and the first embodiment indicate the same or corresponding components as those of the above-mentioned conventional example and the first embodiment.

In the figure, reference numeral 26 denotes a normally open contact 26a for shutting off the output of the diode bridge 17 for charging, and a normally closed contact 26b for connecting the charging resistor 18 to the electrolytic capacitor 14 in parallel to discharge the electric charge. It is a equipped contactor. The control circuit of the contactor 26 has the same configuration as the circuit of FIG. 2, but 24 is a coil of the contactor 26, and 21a is an auxiliary contact of the contactor 26.

Next, the operation of the maintenance safety device for the linear elevator of this embodiment will be described. In the present embodiment, the maintenance worker 10 is engaged before the tightening work of the terminal screw of the connecting portion 9 between the power cable 8 and the linear motors 3a to 3f is started.
When the car upper switch 22 of the elevator car 1 that is stopped is operated to the shut-off state, the contactor 12 is in the open state and the auxiliary contact 23 is also open because the elevator is not in operation, so the coil 24 is deenergized. The normally open contact 26a of the contactor 26 is open and the normally closed contact 26b is closed. Then, the electric charge accumulated in the electrolytic capacitor 14 through the charging resistor 18 until then is discharged through the charging resistor 18 and the normally closed contact 26 b of the contactor 26. Since this discharge continues until the electric charge is completely lost, the voltage across the electrolytic capacitor 14 eventually becomes zero, and even if the output of the inverter 15 and the power cable 8 are connected, the maintenance worker 10 will get an electric shock. There is no. Moreover, while the car top switch 22 is open, the auxiliary contact 21
The coil 25 of the contactor 12 is forcibly maintained in the deenergized state by a, and the power supply is not connected even if the elevator is accidentally started. Conversely, while the elevator is operating normally and the inverter 15 is operating, the contactor 12
The auxiliary car contact 23 short-circuits the on-car switch 22 to prevent the output of the inverter 15 from being cut off during traveling due to poor contact of the on-car switch 22.

As described above, the maintenance safety device for the linear elevator according to this embodiment is similar to the contactor 2 as in the above embodiment.
Instead of shutting off the output of the inverter 15 at 1, the contactor 26 shuts off the charging circuit. That is,
The elevator car 1 is moved to bring the elevator car 1 and the counterweight 2 into a predetermined positional relationship, and the connection portion 9 between the linear motors 3, 3a to 3f mounted on the counterweight 2 and the power cable 8 is maintained. At the time of inspection work, the contactor 26 is set by the car upper switch 22 arranged on the upper part of the elevator car 1.
The output of the charging circuit is cut off and the voltage of the electrolytic capacitor 14 is discharged at the same time, and the linear motors 3, 3a-3
The output path of the inverter 15 that drives f is cut off.

Therefore, when performing maintenance work such as tightening the terminal screw of the connection portion 9 between the power cable 8 and the linear motors 3, 3a to 3f, the inverter 15 is installed at a place where the power is turned off before the work. You do n’t have to go
One operator can disconnect the inverter 15 from the power source, and even if the elevator start button is accidentally pressed during maintenance work, the inverter 15 does not operate, and a fire or the like due to a short circuit accident of the output of the inverter 15 does not occur. There is no risk of the maintenance worker 10 being electrocuted. As a result, as in the case of the above embodiment, one maintenance worker 10 can easily and safely perform maintenance work such as retightening of the terminal screw of the connection portion 9.

<Third Embodiment> FIG. 4 is a circuit diagram showing a contactor control circuit of a maintenance safety device for a linear elevator according to a third embodiment of the present invention. Note that FIGS. 5 and 6 are common to the conventional example, the first and second examples, and the description thereof is omitted here. In the drawing, the same reference numerals and symbols as those of the above-mentioned conventional example, the first and second embodiments indicate the same or corresponding constituent parts as those of the above-mentioned conventional example, the first and second embodiments.

In the figure, reference numeral 31 is an operation stop switch which is usually disposed above the elevator car 1 for ensuring safety during maintenance work. The operation stop switch 31 is connected in series with the safety circuit switch group. When the operation stop switch 31 is turned off, the safety circuit switch group is also cut off and the elevator stops operating. In this control circuit, when the operation stop switch 31 is turned off, the coil 24 is also deenergized at the same time. Therefore, the contactor 21 shown in FIG. 1 or the contactor 2 shown in FIG.
6 operates as described in the above embodiment, and the inverter 15
The output path of is cut off. Therefore, the original purpose can be achieved without providing a new on-car switch 22 on the elevator car 1.

As described above, the maintenance safety device for the linear elevator according to the present embodiment has the coil 24 as in the above embodiments.
Instead of using the on-car switch 22, the operation stop switch 31 used for normal maintenance work is substituted for the energizing and deactivating switching of. That is, the elevator car 1 is moved to bring the elevator car 1 and the counterweight 2 into a predetermined positional relationship, and the connecting portion 9 between the linear motors 3, 3a to 3f mounted on the counterweight 2 and the power cable 8 is connected. When carrying out maintenance and inspection work on the vehicle, the normal operation stop switch 31 arranged on the upper part of the elevator car 1 is used to operate the contactor 21.
Alternatively, via the contactor 26, the linear motors 3, 3a
The output path of the inverter 15 that drives 3f is cut off.

Therefore, also in this embodiment, the power cable 8 and the linear motors 3 and 3a are used as in the above embodiments.
When performing maintenance work such as tightening the terminal screw of the connection part 9 to 3f, it is not necessary to bother to go to the installation place of the inverter 15 to turn off the power supply before the work, and one operator can operate the inverter 15 together. Power supply and linear motor 3, 3a-
3f can be disconnected, and even if the elevator start button is pressed by mistake during maintenance work, the inverter 15 does not operate, fire due to a short-circuit accident of the output of the inverter 15 does not occur, and the maintenance worker 10 may get an electric shock. There is none. As a result, as in the case of the above embodiment, one maintenance worker 10 can easily and safely perform maintenance work such as retightening of the terminal screw of the connection portion 9. In particular, it is not necessary to provide a new on-car switch 22.

By the way, in each of the above embodiments, the contactor 21 is provided between the inverter 15 and the power cable 8 of the maintenance safety device for the linear elevator, or the contactor 26 is provided in the charging circuit. However, a circuit configuration in which both of them are arranged may be used.

[0029]

As described above, the maintenance safety device for a linear elevator according to the present invention includes a counterweight, a linear motor, a connecting portion, and a switch, and the elevator car and the counterweight are provided in a predetermined manner. When performing maintenance work on the connection between the linear motor mounted on the counterweight and the power cable in a positional relationship, the output path of the inverter that drives the linear motor is set by the switch installed on the top of the elevator car. By shutting off, when performing such maintenance work,
The inverter can be disconnected from the power supply and the linear motor by a single worker, and even if the elevator start button is accidentally pressed during maintenance work, the inverter will not operate and there is no risk of electric shock to the maintenance worker. Maintenance work can be done easily and safely by one maintenance worker.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a main circuit of a maintenance safety device for a linear elevator according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a control circuit of a contactor of a maintenance safety device for a linear elevator that is the first and second embodiments of the present invention.

FIG. 3 is a circuit diagram showing a main circuit of a maintenance safety device for a linear elevator that is a second embodiment of the present invention.

FIG. 4 is a circuit diagram showing a contactor control circuit of a maintenance safety device for a linear elevator according to a third embodiment of the present invention.

FIG. 5 is a front view showing a state during maintenance work of the conventional and the linear elevators of the present invention.

FIG. 6 is a front view showing an arrow AA of FIG.

FIG. 7 is a circuit diagram showing a main circuit of a conventional maintenance safety device for a linear elevator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Elevator car 2 Counterweight 3, 3a-3f Linear motor 7 Secondary conductor 8 Power cable 9 Connection part 12 Contactor 14 Electrolytic capacitor 15 Inverter 21 Contactor 21a Auxiliary contact 22 Car switch 23 Auxiliary contact 24 Coil 25 Coil 26 Contactor 31 Shutdown switch

Claims (1)

[Claims] 1. A counterweight connected to an elevator car via a wire rope and moved up and down in a hoistway along a secondary conductor; a linear motor mounted on the counterweight and driven by an inverter; By placing the elevator car and the counterweight in a predetermined positional relationship, the connecting portion between the linear motor and the power cable that enables maintenance and inspection work, and the output of the inverter that is arranged on the upper part of the elevator car A maintenance safety device for a linear elevator, comprising: a switch capable of interrupting a path.