CN-122029735-A - Electromagnetic brake control device and winch
Abstract
An electromagnetic brake control device (55) for controlling an electromagnetic brake (54) in which the rotation of an alternating current motor (53) is braked when the energization of an electromagnetic brake coil (54 a) is interrupted, comprises a rectifier (81) connected to the electromagnetic brake coil (54 a) on the DC side, a switching unit (84) for switching on and off a rectifier circuit (RL) connected to the rectifier (81) and the electromagnetic brake coil (54 a) to control the electric power to the electromagnetic brake coil (54 a), a DC converter (82) connected to a motor-driven AC circuit (51 a) to convert the alternating current electric power into a predetermined DC voltage, an electromagnetic brake release circuit unit (85) for switching the switching unit (84) into an on state by using the DC voltage generated by the DC converter (82), and an electromagnetic brake operation command unit (83) for switching the switching unit (84) to a state when the value of the current waveform of the alternating current motor (53) is in a state between a positive threshold and a negative threshold and a predetermined time or longer than a predetermined judgment time.
Inventors
- SAKAMOTO YUUKI
- IDO YUSAKU
Assignees
- 株式会社开道
Dates
- Publication Date
- 20260512
- Application Date
- 20240925
- Priority Date
- 20231018
Claims (5)
- 1. An electromagnetic brake control device for controlling an electromagnetic brake for braking rotation of an AC motor when energization of an electromagnetic brake coil is cut off, The electromagnetic brake control device is characterized by comprising: A rectifier, the ac side of which is connected to a motor drive ac circuit that supplies drive power to the ac motor, and the dc side of which is connected to the electromagnetic brake coil, and which rectifies ac to dc; a switching unit that switches a rectifier circuit that connects the rectifier and the electromagnetic brake coil to an on state and an off state, thereby controlling power supply to the electromagnetic brake coil; A dc converter connected to the motor-driven ac circuit and converting ac power into a predetermined dc voltage; an electromagnetic brake release circuit unit for switching the switching unit to an on state by using the DC voltage generated by the DC converter, and And an electromagnetic brake operation command unit that switches the switching unit to a shut-off state when the value of the current waveform of the ac motor is between a positive threshold value and a negative threshold value including a zero-crossing point and the predetermined determination time or longer.
- 2. The electromagnetic brake control apparatus according to claim 1, wherein, The ac motor is a three-phase ac motor, The rectifier is a full wave rectifier with an ac side connected in series with one phase of the motor drive ac circuit.
- 3. The electromagnetic brake control apparatus according to claim 1, wherein, The electromagnetic brake actuation command unit has a window comparator and a determination unit, The window comparator outputs a high-level signal to the determination unit when the value of the current waveform of the ac motor is between a positive threshold value and a negative threshold value including a zero-crossing point, The determination unit switches the rectifier circuit to the off state by the switching unit when the input of the high-level signal from the window comparator continues for the determination time or longer.
- 4.A hoist is characterized by comprising: An ac motor that is driven to rotate by applying an ac current to raise and lower a suspended load; a motor drive ac circuit that energizes the ac motor with drive power; an electromagnetic brake for braking rotation of the AC motor when energization of an electromagnetic brake coil is cut off, and An electromagnetic brake control unit that controls the electromagnetic brake, The electromagnetic brake control unit includes: A rectifier, the AC side of which is connected with the motor driving AC circuit, and the DC side of which is connected with the electromagnetic brake coil; a switching unit that switches a rectifier circuit that connects the rectifier and the electromagnetic brake coil to an on state and an off state; A dc converter connected to the motor-driven ac circuit and converting ac power into a predetermined dc voltage; an electromagnetic brake release circuit unit for switching the switching unit to an on state by using the DC voltage generated by the DC converter, and And an electromagnetic brake operation command unit that switches the switching unit to a shut-off state when the value of the current waveform of the ac motor is between a positive threshold value and a negative threshold value including a zero-crossing point and the predetermined determination time or longer.
- 5. A hoist is characterized by comprising: An ac motor that is driven to rotate by applying an ac current to raise and lower a suspended load; a motor drive ac circuit that energizes the ac motor with drive power; a first electromagnetic brake that brakes rotation of the ac motor when power to the first electromagnetic brake coil is turned off; a second electromagnetic brake that brakes rotation of the ac motor when power to the second electromagnetic brake coil is turned off; a first electromagnetic brake control section for controlling the first electromagnetic brake, and A second electromagnetic brake control unit that controls the second electromagnetic brake, The first electromagnetic brake control unit includes: A first rectifier having an ac side connected to the motor driving ac circuit and a dc side connected to the first electromagnetic brake coil; a switching unit that switches a rectifier circuit that connects the first rectifier and the first electromagnetic brake coil to an on state and an off state; A dc converter connected to the motor-driven ac circuit and converting ac power into a predetermined dc voltage; an electromagnetic brake release circuit unit for switching the switching unit to an on state by using the DC voltage generated by the DC converter, and An electromagnetic brake operation command unit that switches the switching unit to a shut-off state when a value of a current waveform of the ac motor is between a positive threshold value and a negative threshold value including a zero-crossing point and a predetermined determination time or longer, The second electromagnetic brake control portion has a second rectifier, the ac side of which is connected to the motor drive ac circuit, the dc side is directly connected to the second electromagnetic brake coil, The direct current rectified by the second rectifier is always supplied to the second electromagnetic brake coil.
Description
Electromagnetic brake control device and winch Technical Field The invention relates to an electromagnetic brake control device and a winch. Background Patent document 1 discloses that a current converted into a direct current by a bridge diode is branched from one phase of a three-phase alternating current circuit connecting a power supply and a motor, and flows through an electromagnetic brake coil, whereby a brake is released. In such a circuit, a dc loop is formed in which a current flows from the bridge diode through the electromagnetic brake coil and then back to the bridge diode. Therefore, immediately after the energization of the motor is stopped, a delay occurs before the energization of the loop is stopped due to the inductance component of the electromagnetic brake coil, and there is a possibility that the brake is delayed and the load is shifted. [ Prior Art literature ] [ Patent literature ] Patent document 1 Japanese patent, japanese patent laid-open publication No. 57-019297 Disclosure of Invention (Problem to be solved by the invention) In patent document 1, in order to cut off the energization due to such an inductance component, a transistor is mounted in the loop, but since a capacitor is included in a circuit for supplying a base current, the base current is supplied to the transistor until the charge of the capacitor disappears, and the loop cannot be cut off. Further, since an ac current is converted to a dc current only by a bridge diode and is used as a base current of a transistor, the transistor is turned on and off based on an analog signal, and thus it is difficult to control without delay. The present invention has been made in view of the above-described problems, and an object thereof is to provide an electromagnetic brake control device, a hoist, and a hoist system that further control an electromagnetic brake without delay. (Means for solving the problems) An electromagnetic brake control device according to one aspect of the present invention is an electromagnetic brake control device for controlling an electromagnetic brake that brakes rotation of an alternating-current motor when energization of an electromagnetic brake coil is interrupted, comprising a rectifier connected to a motor drive alternating-current circuit that drives the alternating-current motor, the direct-current side being connected to the electromagnetic brake coil and rectifying alternating current to direct current, a switching unit that switches a rectifying circuit that connects the rectifier to the electromagnetic brake coil to an on state and an off state to control power supply to the electromagnetic brake coil, a direct-current converter connected to the motor drive alternating-current circuit and converting alternating-current power to a predetermined direct-current voltage, an electromagnetic brake release circuit unit that switches the switching unit to an on state by using the direct-current voltage generated by the direct-current converter, and an electromagnetic brake operation command unit that switches the switching unit to the off state when a value of a current waveform of the alternating-current motor is between a positive threshold value including a zero crossing point and a negative threshold value and a predetermined determination time or longer. The ac motor is a three-phase ac motor, and the rectifier is a full-wave rectifier having an ac side connected in series with one phase of a motor drive ac circuit. The electromagnetic brake operation command unit includes a window comparator that outputs a high-level signal to the determination unit when the value of the current waveform of the ac motor is between a positive threshold value and a negative threshold value including a zero-crossing point, and a determination unit that switches the rectifier circuit to an off state by the switching unit when the input of the high-level signal from the window comparator continues for a determination time or longer. A hoist according to one aspect of the present invention includes an ac motor that is rotationally driven by an ac current to raise and lower a suspended load, a motor-driven ac circuit that energizes the ac motor with drive power, an electromagnetic brake that brakes rotation of the ac motor when energization of an electromagnetic brake coil is turned off, and an electromagnetic brake control unit that controls the electromagnetic brake, the electromagnetic brake control unit including a rectifier that is connected to the motor-driven ac circuit on an ac side and is connected to the electromagnetic brake coil on a dc side, a switching unit that switches a rectifier circuit that is connected to the rectifier and the electromagnetic brake coil to an on state and an off state, a dc converter that is connected to the motor-driven ac circuit to convert ac power to a predetermined dc voltage, an electromagnetic brake release circuit unit that switches the switching unit to an on state by