Elevator control device

Patent metadata

Field	Value
Publication number	US-12486143-B2
Application number	US-201817269250-A
Country	US
Kind code	B2
Filing date	Oct 3, 2018
Priority date	Oct 3, 2018
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

Provided is a control device for an elevator including: a first control unit configured to control a hoisting machine configured to raise and lower a car and a counterweight in a hoistway; and a second control unit configured to obtain a generation torque which is a torque to be generated by the hoisting machine, and to limit the obtained generation torque to be generated by the hoisting machine so that the obtained generation torque is lower than an abnormal torque which is the generation torque generated when, under a state in which a movement of one of elevating bodies which are the car and the counterweight is limited, the other elevating body is wound by the hoisting machine.

First claim

The invention claimed is:

1 . A control device for an elevator, comprising:
a first control circuit configured to control a hoisting machine configured to raise and lower a car and a counterweight in a hoistway; and a second control circuit configured to obtain a generation torque which is a torque to be generated by the hoisting machine, and to limit the obtained generation torque to be generated by the hoisting machine so that the obtained generation torque is lower than an abnormal torque which is the generation torque generated when, under a state in which a movement of one of elevating bodies which are the car and the counterweight is limited, the other elevating body is wound by the hoisting machine, wherein the abnormal torque is a torque generated when the other elevating body is wound by the hoisting machine under one of a state in which the movement of the car being the one elevating body is limited by an emergency stop device provided for the car or a state in which the counterweight being the one elevating body is in contact with a buffer provided in the hoistway so that a downward movement of the counterweight is limited.

2 . The control device for an elevator according to claim 1 ,
wherein a value equal to or lower than the abnormal torque is set as a first torque threshold value, and wherein, when the obtained generation torque is equal to or higher than the first torque threshold value, the second control circuit performs first torque reduction control of reducing the generation torque to be generated by the hoisting machine to a value lower than the first torque threshold value, to thereby limit the generation torque.

3 . The control device for an elevator according to claim 2 , wherein the second control circuit is configured to shut off supply of power to the hoisting machine, to thereby stop the hoisting machine as the first torque reduction control.

4 . The control device for an elevator according to claim 2 , wherein the second control circuit is configured to cause the first control circuit to perform control of continuing drive of the hoisting machine as the first torque reduction control under a state in which the generation torque to be generated by the hoisting machine is reduced to a value lower than the first torque threshold value.

5 . The control device for an elevator according to claim 2 , wherein the second control circuit is configured to:
obtain a car position which is a position of the car; and correct the first torque threshold value in accordance with the obtained car position.

6 . The control device for an elevator according to claim 2 ,
wherein a value lower than the first torque threshold value is set as a second torque threshold value, and wherein, when the obtained generation torque is equal to or higher than the second torque threshold value and is lower than the first torque threshold value, the second control circuit performs second torque reduction control of reducing the generation torque to be generated by the hoisting machine to a torque lower than the second torque threshold value, to thereby limit the generation torque.

7 . The control device for an elevator according to claim 6 , wherein the second control circuit is configured to shut off supply of power to the hoisting machine, to thereby stop the hoisting machine as the second torque reduction control.

8 . The control device for an elevator according to claim 6 , wherein the second control circuit is configured to cause the first control circuit to perform control of continuing drive of the hoisting machine as the second torque reduction control under a state in which the generation torque to be generated by the hoisting machine is reduced to a value lower than the second torque threshold value.

9 . The control device for an elevator according to claim 6 , wherein the second control circuit is configured to:
obtain a car position which is a position of the car; and correct the second torque threshold value in accordance with the obtained car position.

10 . The control device for an elevator according to claim 1 , wherein the second control circuit is provided independently of the first control circuit.

11 . The control device for an elevator according to claim 1 ,
wherein the hoisting machine includes a three-phase motor, and wherein the second control circuit is configured to: further obtain current information on a current flowing through the three-phase motor; and calculate the generation torque based on the obtained current information, to thereby obtain the generation torque.

12 . The control device for an elevator according to claim 11 , wherein the second control circuit is configured to:
further obtain rotation information on rotation of the three-phase motor; detect three-phase currents flowing through the three-phase motor from the obtained current information; detect a rotation position of the three-phase motor from the obtained rotation information; apply coordinate conversion to the three-phase currents based on the rotation position, to thereby calculate a current vector on dq axes; and calculate the generation torque based on a magnitude of a q-axis current which is a q-axis component of the calculated current vector.

13 . The control device for an elevator according to claim 11 ,
wherein the first control circuit is configured to control a d-axis current in the current flowing through the three-phase motor so as to be 0 when the first control circuit uses vector control to control the three-phase motor, and wherein the second control circuit is configured to: detect three-phase currents flowing through the three-phase motor from the obtained current information; apply coordinate conversion to the three-phase currents, to thereby calculate a current vector on dq axes; and calculate the generation torque based on a magnitude of the calculated current vector.

14 . A control device for an elevator, comprising:
a first control circuit configured to control a hoisting machine configured to raise and lower a car and a counterweight in a hoistway; and a second control circuit configured to obtain a generation torque which is a torque to be generated by the hoisting machine, and to limit the obtained generation torque to be generated by the hoisting machine so that the obtained generation torque is lower than an abnormal torque which is the generation torque generated when, under a state in which a movement of one of elevating bodies which are the car and the counterweight is limited, the other elevating body is wound by the hoisting machine, wherein the abnormal torque is the generation torque generated when the car being the other elevating body is wound by the hoisting machine under a state in which the counterweight being the one elevating body is in contact with a buffer provided in the hoistway so that a downward movement of the counterweight is limited.

15 . A control device for an elevator, comprising:
a first control circuit configured to control a hoisting machine configured to raise and lower a car and a counterweight in a hoistway; and a second control circuit configured to obtain a generation torque which is a torque to be generated by the hoisting machine, and to limit the obtained generation torque to be generated by the hoisting machine so that the obtained generation torque is lower than an abnormal torque which is the generation torque generated when, under a state in which a movement of one of elevating bodies which are the car and the counterweight is limited, the other elevating body is wound by the hoisting machine,

Assignees

• Mitsubishi Electric Corp

Inventors

• Ishiguro Hidetaka

Classifications

• B66B5/16

  Braking or catch devices operating between cars, cages, or skips and fixed guide elements or surfaces in hoistway or well · CPC title

• B66B1/3492

  Position or motion detectors or driving means for the detector (B66B1/40, B66B1/50 take precedence; length measuring G01B; speed measuring G01P) · CPC title

• B66B5/125 Primary

  electrical · CPC title

• B66B5/10 Primary

  electrical · CPC title