JP-7856780-B2 - Brake drive unit that drives the mechanical brake system

Inventors

• 稲垣 慶太郎

Assignees

• ファナック株式会社

Dates

Publication Date

20260511

Application Date

20221025

Claims (5)

1. A switch that, when turned ON to supply current to the mechanical brake device, releases the brake by the mechanical brake device, and when turned OFF to stop current from flowing to the mechanical brake device, activates the brake by the mechanical brake device. An energy storage circuit electrically connected to the aforementioned mechanical brake device and storing energy, A switch control unit controls the switch to be turned on and the brake by the mechanical brake device released while the switch is turned on, to keep the switch off for a certain period of time. Equipped with, A brake drive device that supplies energy from an energy storage circuit to the mechanical brake device to suppress current changes when the brake by the mechanical brake device is released.
2. A detection unit detects the potential of the power line connecting the switch and the mechanical brake device when the switch is turned ON by the control of the switch control unit, thereby releasing the brake by the mechanical brake device, and the switch is turned OFF for a certain period of time. A diagnostic unit diagnoses whether or not the switch is faulty based on the detection result of the detection unit, The brake drive device according to claim 1 , comprising:
3. The brake drive device according to claim 1 or 2 , wherein the energy storage circuit has a capacitor connected in parallel with the brake coil of the mechanical brake device.
4. The brake drive device according to claim 1 or 2 , wherein the energy storage circuit has an inductor connected in series with the brake coil of the mechanical brake device.
5. The brake drive device according to claim 1 or 2, wherein the mechanical brake device applies a brake to the motor by pressing the armature against a friction plate connected to the motor shaft using the elastic force of a spring, and releases the brake to the motor by pulling the armature away from the friction plate using the electromagnetic force generated when current flows through the brake coil.

Description

This disclosure relates to a brake drive system for driving a mechanical brake system. In motor drive systems that drive motors within machines such as industrial robots and machine tools, mechanical brake systems are widely used to apply brakes to rotating motors or to fix stationary motors in place to prevent them from rotating. A switch is connected between the brake coil and the power supply of the mechanical brake system. When the switch is turned on, current flows from the power supply to the brake coil, releasing the brake of the mechanical brake system. Conversely, when the switch is turned off, current does not flow from the power supply to the brake coil, activating the brake of the mechanical brake system. Japanese Patent Publication No. 2013-248946Japanese Patent Publication No. 2011-195287Japanese Patent Publication No. 2020-029877 This is a circuit diagram showing a brake drive device according to the first embodiment of the present disclosure.This is a cross-sectional view showing the structure of a mechanical brake device controlled by a brake drive device according to the first and second embodiments of the present disclosure, showing the state in which the brake is applied to the motor.This is a cross-sectional view showing the structure of a mechanical brake device controlled by a brake drive device according to the first and second embodiments of the present disclosure, showing a state in which the brake on the motor is released.This is a circuit diagram showing a brake drive device according to a second embodiment of the present disclosure.This is a timing chart illustrating the waveforms in the brake drive device according to the first and second embodiments of this disclosure.This is a timing chart showing the waveforms when the brake drive device according to the first and second embodiments of this disclosure is actually operated.This timing chart shows the waveforms when a conventional brake drive system without an energy storage circuit is actually operated. The brake drive device that drives the mechanical brake device of the embodiment will be described below with reference to the drawings. In the following description, components having the same or similar functions will be denoted by the same reference numerals. Duplication of these components may be omitted. Here, "on" of the switch means that the circuit to which the switch is provided is closed; that is, when the switch is turned on, the circuit to which the switch is provided is connected and becomes closed. "Off" of the switch means that the circuit to which the switch is provided is open; that is, when the switch is turned off, the circuit to which the switch is provided is interrupted and becomes open. <Configuration of the brake drive device according to the first embodiment> Figure 1 is a circuit diagram showing a brake drive device according to a first embodiment of the present disclosure. The mechanical brake device 2 controlled by the brake drive device 1 according to the first embodiment of this disclosure is an unexcited type brake device that operates the brake when no voltage is applied to the brake coil 25 and releases the brake when voltage is applied to the brake coil 25. Before describing the brake drive device 1 according to the first embodiment of this disclosure, the structure of the mechanical brake device 2 will be described with reference to Figures 2 and 3. Figure 2 is a cross-sectional view showing the structure of the mechanical brake device controlled by the brake drive device according to the first and second embodiments of this disclosure, showing the state in which the brake is applied to the motor. Figure 3 is a cross-sectional view showing the structure of the mechanical brake device controlled by the brake drive device according to the first and second embodiments of this disclosure, showing the state in which the brake is released from the motor. The mechanical brake device 2 shown in Figures 2 and 3 is applicable to the first and second embodiments. As shown in Figures 2 and 3, in the mechanical brake device 2, a friction plate 21 is positioned between the armature 22 and the end plate 23. A hub 32 is spline-coupled to the friction plate 21. Since the hub 32 and the motor shaft 31 are integrated, for example by shrink-fitting, the friction plate 21 rotates in conjunction with the rotation of the motor shaft 31. The end plate 23 and the spacer 27 are connected by bolts 28, and the armature 22 is coupled to the spacer 27 so that it can move toward and away from the friction plate 21. A spring 24 and a brake coil 25 are provided inside the core 26. As shown in Figure 2, in the unexcited state where no voltage is applied to the brake coil 25, the armature 22 is strongly pressed against the friction plate 21 by the elastic force of the spring 24, and the friction plate 21 is sandwiched between the armature 22 and the end plate 23 and cannot rotate. As a result, the motor shaft 31 coupled to the