Brake control device and motor drive device

Abstract

A brake control device for controlling a power-off brake device, the brake control device comprising: a power supply controlled so as to output a voltage or so as not to output a voltage in accordance with a power supply control signal; a brake control unit for outputting a brake control signal; an opening / closing unit for opening / closing an electric circuit between the power supply and the brake device in accordance with the brake control signal; a state detection unit for outputting a state detection signal indicating the potential state of the electric circuit between the opening / closing unit and the brake device; an abnormality detection unit for detecting whether or not an abnormality has occurred on the basis of a combination of the details of the brake control signal and the details of the state detection signal; and a power supply control unit for outputting, as the power supply control signal for the power supply, an output-off signal for controlling the power supply so as not to output a voltage when the abnormality detection unit determines that an abnormality has occurred.

Description

[Technical field]

[0001] The present invention relates to a brake control device and a motor drive device. [Background technology]

[0002] In a non-excitation actuated brake device, the brake is actuated when no voltage is applied to the brake coil (non-excitation), and the brake is released when the brake coil is excited (excitation) and a voltage is applied to the brake coil.

[0003] For example, there is known an electromagnetic brake control device that controls a non-excitation actuated electromagnetic brake, which includes an output terminal for connecting the electromagnetic brake, and a brake control unit that outputs a brake control signal supplied to the electromagnetic brake via the output terminal, and which outputs a brake control signal for releasing the electromagnetic brake when both a normal brake command and a safety brake command are ON, and outputs a brake control signal for applying the electromagnetic brake when at least one of the normal brake command and the safety brake command is OFF (see, for example, Patent Document 1).

[0004] For example, a brake drive control circuit is known that controls an electromagnetic brake that releases the brake when current is applied, the brake drive control circuit having a first rectifying element provided between a first power source of a first circuit voltage and one terminal of the electromagnetic brake, a cut-off switch inserted in a line that supplies power to the first power source to operate the first power source, a first switching element provided between the other terminal of the electromagnetic brake and a ground point, and a second switching element and a second rectifying element provided in series between a second power source of a second circuit voltage different from the first circuit voltage and the one terminal of the electromagnetic brake (see, for example, Patent Document 2).

[0005] For example, in a non-excitation operation type electromagnetic brake control device in which an electromagnetic brake is applied when the excitation coil is in a non-excitation state, there is known an electromagnetic brake control circuit comprising a first brake control circuit having a first calculation unit that performs calculation processing in accordance with a brake command and a first switch that is turned on by a brake signal generated based on the output signal of the first calculation unit, and a second brake control circuit having a second calculation unit that performs calculation processing in accordance with a brake command and a second switch that is turned on by a brake signal generated based on the output signal of the second calculation unit, wherein the first switch and the second switch are connected in series between a brake power supply and the electromagnetic brake (see, for example, Patent Document 3).

[0006] For example, paragraph 0031 of Patent Document 4 states, "Furthermore, when brake power P2 for releasing the brake is not supplied from the brake control unit 7 (see FIG. 1) to the electromagnetic brake 2, the electromagnetic coil 24 is configured not to be driven. In this case, as shown in FIG. 2, the armatures 20a and 20b are pressed against the brake hub 22 (brake shoe 27) by the biasing forces of the torque springs 21a and 21b. As a result, the rotating shaft 14 of the motor 1 is in a brake-applied state (locked state) without rotating. At this time, a gap (gap) is formed between the armatures 20a and 20b and the field core 23, and the first detector 28a and the second detector 28b are in an OFF state (locked position)." Patent Document 4 Paragraph 0032 of the same document states, "Furthermore, when brake power P2 for releasing the brake is supplied to the electromagnetic brake 2, the electromagnetic coil 24 is configured to be driven. In this case, as shown in FIG. 3, the armature 20 moves toward the electromagnetic coil 24 against the elastic force of the torque spring 21. As a result, the armature 20 and the brake hub 22 (brake shoe 27) move in directions away from each other, thereby releasing the brake. This enables the rotating shaft 14 of the motor 1 to be rotated. At this time, no gap (gap) is formed between the armatures 20a and 20b and the field core 23, and the first detector 28a and the second detector 28b are in the ON state (released position)." [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2020-089137 A [Patent Document 2] JP 2019-105286 A [Patent Document 3] International Publication No. 2014 / 045728 [Patent Document 4] JP 2012-237397 A Summary of the Invention [Problem to be solved by the invention]

[0008] In a non-excitation actuation type brake device, an open / close switch is provided on a circuit consisting of a brake coil and a power source, and the presence or absence of excitation of the brake coil is controlled by opening and closing the open / close switch. If an abnormality occurs, such as a short circuit failure of the open / close switch, a failure of the control unit that controls the open / close switch, or a short circuit between the circuit consisting of the brake coil and the power source and a circuit other than the brake device, the brake may be released when the brake should be activated. For example, in a brake device provided for a motor that drives a robot's arm, if the brake is released due to some abnormality when the brake should be activated, it may cause a very dangerous situation in which the robot cannot maintain its posture or the arm falls. Therefore, there is a need for the development of a safe non-excitation actuation type brake device and motor drive device that can prevent the brake from being released when an abnormality occurs. [Means for solving the problem]

[0009] According to one aspect of the present disclosure, a brake control device that controls a non-excitation operation type brake device that activates a brake when no voltage is applied and is not excited, and releases the brake when voltage is applied and is excited, includes: a power source that is controlled to output a voltage or not output a voltage in response to a received power source control signal; a brake control unit that outputs a brake control signal; an opening / closing unit that is connected in series to the brake device and opens and closes an electric path between the power source and the brake device in response to the received brake control signal; a state detection unit that outputs a state detection signal that indicates a potential state of the electric path between the opening / closing unit and the brake device; an abnormality detection unit that detects whether or not an abnormality has occurred based on a combination of the contents of the brake control signal and the contents of the state detection signal; and a power source control unit that outputs an output off signal as a power source control signal for the power source, which controls the power source not to output a voltage when the occurrence of an abnormality is detected by the abnormality detection unit. the opening / closing unit has at least one positive side opening / closing switch which opens and closes an electric path between a positive terminal of the power supply and a positive terminal of the brake device, and at least one negative side opening / closing switch which opens and closes an electric path between a negative terminal of the power supply and a negative terminal of the brake device; the brake control unit executes a brake activation process which outputs a brake control signal which controls the positive side opening / closing switch and the negative side opening / closing switch to be opened, a brake release process which outputs a brake control signal which controls the positive side opening / closing switch and the negative side opening / closing switch to be closed, and a brake release preparation process which outputs a brake control signal which controls the positive side opening / closing switch to be closed and the negative side opening / closing switch to be opened between the brake activation process and the brake release process when transitioning from the brake activation process to the brake release process; the abnormality detection unit detects whether or not an abnormality has occurred based on a combination of the content of the brake control signal and the content of the state detection signal during the execution of the brake activation process and the execution of the brake release preparation process; and the power supply control unit outputs an output off signal when the abnormality detection unit detects an abnormality both during the execution of the brake activation process and the execution of the brake release preparation process. do.

[0010] Furthermore, according to one aspect of the present disclosure, the motor drive device includes a non-excitation actuated brake device that activates a brake on the motor when the motor is not excited and no voltage is applied, and releases the brake on the motor when the motor is excited and a voltage is applied, and the above-mentioned brake control device that controls the brake device. Effect of the Invention

[0011] According to one aspect of the present disclosure, it is possible to realize a safe de-excitation operation type brake device and motor drive device that can prevent the brake from being released when an abnormality occurs. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating a brake control device and a motor drive device including the brake control device according to a first and second embodiment of the present disclosure. [Figure 2A] 1 is a cross-sectional view showing the structure of a non-excitation actuation type brake device, illustrating a state in which the brake is actuated on the motor. [Figure 2B] FIG. 2 is a cross-sectional view showing the structure of a non-excitation actuation type brake device, illustrating a state in which the brake on the motor is released. [Figure 3A] FIG. 2 is a diagram for explaining each signal and brake state in a normal state in the brake control device according to the first embodiment of the present disclosure, showing a table showing each signal and brake state. [Figure 3B] FIG. 2 is a timing chart illustrating each signal and brake state in a normal state in the brake control device according to the first embodiment of the present disclosure. FIG. [Figure 4A] FIG. 2 is a diagram for explaining each signal and brake state when a short-circuit fault occurs only in the positive side opening and closing switch in the brake control device 1 according to the first embodiment of the present disclosure, and shows a table showing each signal and brake state. [Figure 4B]FIG. 2 is a timing chart illustrating each signal and brake state when a short circuit occurs only in the positive side opening and closing switch in the brake control device 1 according to the first embodiment of the present disclosure. FIG. [Figure 5A] FIG. 13 is a diagram explaining the signals and brake states when a short circuit occurs only in the negative side opening / closing switch in a brake control device when there is no output control of the power supply and a constant voltage is output, and shows a table showing the signals and brake states. [Figure 5B] FIG. 13 is a timing chart showing each signal and brake state when a short circuit occurs only in the negative side opening / closing switch in a brake control device when there is no output control of the power supply and a constant voltage is output. [Figure 6A] FIG. 1 is a diagram for explaining each signal and brake state when a short circuit occurs only in the negative side opening / closing switch in a brake control device having an output controllable power supply according to the first embodiment of the present disclosure, and shows a table showing each signal and brake state. [Figure 6B] FIG. 11 is a timing chart illustrating the signals and brake states when a short circuit occurs only in the negative side opening / closing switch in a brake control device having an output controllable power supply according to the first embodiment of the present disclosure; [Figure 7A] FIG. 1 is a diagram for explaining each signal and brake state when a short circuit occurs only in the negative side opening / closing switch in a brake control device having a recovery sequence for brake actuation processing according to the first embodiment of the present disclosure, and shows a table showing each signal and brake state. [Figure 7B] FIG. 1 is a timing chart illustrating each signal and brake state when a short circuit occurs only in the negative side opening / closing switch in a brake control device having a recovery sequence for brake actuation processing according to the first embodiment of the present disclosure; [Figure 8A]FIG. 13 is a diagram explaining the signals and brake states when both the positive side opening / closing switch and the negative side opening / closing switch in a brake control device have a short circuit failure when there is no output control of the power supply and a constant voltage is output, and shows a table showing the signals and brake states. [Figure 8B] FIG. 13 is a timing chart showing each signal and brake state when both the positive side opening / closing switch and the negative side opening / closing switch in a brake control device have a short circuit failure when there is no output control of the power supply and a constant voltage is output. [Figure 9A] FIG. 1 is a diagram for explaining each signal and brake state when both the positive side opening / closing switch and the negative side opening / closing switch have a short circuit failure in a brake control device having an output controllable power supply according to a first embodiment of the present disclosure, and shows a table showing each signal and brake state. [Figure 9B] FIG. 1 is a diagram explaining each signal and brake state when both the positive side opening / closing switch and the negative side opening / closing switch have a short circuit failure in a brake control device having an output controllable power supply according to the first embodiment of the present disclosure, and is a timing chart showing each signal and brake state. [Figure 10] 5 is a flowchart showing an operation flow until the brake applied to the motor by the brake device is released in the brake control device according to the first embodiment of the present disclosure. [Figure 11] 11 is a diagram illustrating examples of signals and brake states when the power supply is normal in a brake control device having a first power supply inspection function according to a second embodiment of the present disclosure. FIG. [Figure 12] 13 is a diagram illustrating examples of signals and brake states during a power supply abnormality in a brake control device having a first power supply inspection function according to a second embodiment of the present disclosure. FIG. [Figure 13] 10 is a flowchart showing an operation flow when releasing the brake applied to the motor by the brake device in the brake control device according to the second embodiment of the present disclosure. [Figure 14]13 is a diagram illustrating examples of signals and brake states when the power supply is normal in a brake control device having a second power supply inspection function according to a second embodiment of the present disclosure. FIG. [Figure 15] 13 is a diagram illustrating examples of signals and brake states during a power supply abnormality in a brake control device having a second power supply inspection function according to a second embodiment of the present disclosure. FIG. [Figure 16] 10 is a flowchart showing an operation flow when applying a brake by a brake device that is released with respect to a motor in a brake control device according to a second embodiment of the present disclosure. [Figure 17] 13 is a diagram illustrating a brake control device and a motor drive device including the brake control device according to a third and fourth embodiment of the present disclosure. FIG. [Figure 18A] FIG. 13 is a diagram for explaining each signal and brake state in a normal state in the brake control device 1 according to the third embodiment of the present disclosure, showing a table showing each signal and brake state. [Figure 18B] FIG. 13 is a timing chart illustrating each signal and brake state in a normal state in the brake control device 1 according to the third embodiment of the present disclosure. FIG. [Figure 19A] FIG. 13 is a diagram for explaining each signal and brake state when a short circuit occurs in an opening / closing switch in a brake control device when there is no output control of the power supply and a constant voltage is output, and shows a table showing each signal and brake state. [Figure 19B] FIG. 13 is a timing chart showing each signal and brake state when a short circuit occurs in an opening / closing switch in a brake control device when there is no output control of the power supply and a constant voltage is output. [Figure 20A] FIG. 13 is a diagram for explaining each signal and brake state when a short circuit occurs in an opening / closing switch in a brake control device having an output controllable power supply according to a third embodiment of the present disclosure, and shows a table showing each signal and brake state. [Figure 20B]FIG. 13 is a timing chart illustrating each signal and brake state when a short circuit occurs in an opening / closing switch in a brake control device having an output controllable power supply according to a third embodiment of the present disclosure; [Figure 21A] FIG. 13 is a diagram illustrating each signal and brake state in a brake control device having a power supply inspection function according to a fourth embodiment of the present disclosure, illustrating each signal and brake state when the power supply is normal. [Figure 21B] FIG. 13 is a diagram illustrating each signal and brake state in a brake control device having a power supply inspection function according to a fourth embodiment of the present disclosure, illustrating each signal and brake state during a power supply abnormality. [Figure 22] 13 is a flowchart showing an operation flow when releasing the brake applied to the motor by the brake device in the brake control device according to the fourth embodiment of the present disclosure. [Figure 23] FIG. 13 is a diagram illustrating a brake control device and a motor drive device including the brake control device according to a fifth embodiment of the present disclosure. [Figure 24A] FIG. 13 is a diagram illustrating each signal and brake state in a brake control device according to a fifth embodiment of the present disclosure, illustrating each signal and brake state under normal conditions. [Figure 24B] FIG. 13 is a diagram illustrating each signal and brake state in a brake control device according to a fifth embodiment of the present disclosure, illustrating each signal and brake state during a power supply abnormality. [Figure 25A] FIG. 13 is a diagram illustrating each signal and brake state in a brake control device according to a fifth embodiment of the present disclosure, illustrating each signal and brake state when a short-circuit fault occurs in a negative side opening / closing switch. [Figure 25B] FIG. 13 is a diagram illustrating each signal and brake state in a brake control device according to a fifth embodiment of the present disclosure, illustrating each signal and brake state when a short-circuit fault occurs in a positive side opening / closing switch. [Figure 26A]FIG. 13 is a diagram illustrating the signals and brake states in a brake control device according to the fifth embodiment of the present disclosure, illustrating the signals and brake states when a first protective operation process is performed upon a short-circuit failure of the positive side opening / closing switch and the negative side opening / closing switch. [Figure 26B] FIG. 13 is a diagram illustrating the signals and brake states in a brake control device according to the fifth embodiment of the present disclosure, illustrating the signals and brake states when a second protective operation process is performed upon a short-circuit failure of the positive side opening / closing switch and the negative side opening / closing switch. [Figure 27] FIG. 13 is a diagram illustrating the signals and brake states in a brake control device according to the fifth embodiment of the present disclosure, illustrating the signals and brake states when a third protective operation process is performed upon a short-circuit failure of the positive side opening / closing switch and the negative side opening / closing switch. [Figure 28] FIG. 13 is a diagram showing a case where a device having an external power supply shorts out to a brake cable of the brake control device and a motor drive device including the same according to a fifth embodiment of the present disclosure. [Figure 29A] FIG. 29 illustrates signals and brake states when an external power source device shorts out a brake cable of the brake device as shown in FIG. 28 in a brake control device and a motor drive device equipped with the same according to a fifth embodiment of the present disclosure, and illustrates signals and brake states when protective operation processing is not performed. [Figure 29B] FIG. 29 illustrates examples of signals and brake states when an external power source device shorts out a brake cable of a brake device as shown in FIG. 28 in a brake control device and a motor drive device including the same according to a fifth embodiment of the present disclosure, and illustrates examples of signals and brake states when protective operation processing is performed. [Diagram 30] FIG. 13 is a diagram showing a case where a device having an external power supply shorts out to a brake cable of the brake control device and a motor drive device including the same according to a fifth embodiment of the present disclosure. [Figure 31A]FIG. 31 illustrates an example of each signal and brake state when an external power source device shorts out a brake cable of the brake device as shown in FIG. 30 in a brake control device and a motor drive device including the same according to a fifth embodiment of the present disclosure, and illustrates an example of each signal and brake state when protective operation processing is not performed. [Figure 31B] FIG. 31 illustrates an example of each signal and brake state when an external power source device shorts out a brake cable of the brake device as shown in FIG. 30 in a brake control device and a motor drive device including the same according to a fifth embodiment of the present disclosure, and illustrates an example of each signal and brake state when a protective operation process is performed. [Diagram 32] FIG. 13 is a diagram illustrating a brake control device and a motor drive device including the brake control device according to a sixth embodiment of the present disclosure. [Figure 33A] FIG. 13 is a diagram illustrating each signal and brake state in a brake control device according to a sixth embodiment of the present disclosure, illustrating each signal and brake state under normal conditions. [Figure 33B] FIG. 13 is a diagram illustrating each signal and brake state in a brake control device according to a sixth embodiment of the present disclosure, illustrating each signal and brake state when a short circuit failure occurs in an open / close switch. [Figure 34A] FIG. 13 is a diagram illustrating the signals and brake states in a brake control device according to a sixth embodiment of the present disclosure, illustrating the signals and brake states when a first protective operation process is performed when a short circuit occurs in an opening / closing switch. [Figure 34B] FIG. 13 is a diagram illustrating each signal and brake state in a brake control device according to a sixth embodiment of the present disclosure, illustrating each signal and brake state when a second protective operation process is performed when a short circuit failure occurs in an opening / closing switch. [Figure 34C] FIG. 13 is a diagram illustrating the signals and brake states in a brake control device according to the sixth embodiment of the present disclosure, illustrating the signals and brake states when a third protective operation process is performed when a short circuit occurs in an opening / closing switch. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The brake control device and the motor drive device will be described below with reference to the drawings. In each drawing, the same reference numerals are used for the same components. In addition, the scale of these drawings is appropriately changed to facilitate understanding. In addition, the embodiment shown in the drawings is one example for carrying out the present invention, and the present invention is not limited to the illustrated embodiment.

[0014] FIG. 1 is a diagram illustrating a brake control device and a motor drive device including the brake control device according to first and second embodiments of the present disclosure.

[0015] First, a first embodiment of the present disclosure will be described, but FIG. 1 is also applicable to a second embodiment described later.

[0016] The motor drive device 100 includes a non-excitation actuation type brake device 2 that activates a brake on the motor 3 when it is not excited and no voltage is applied, and releases the brake on the motor 3 when it is excited and a voltage is applied, and a brake control device 1 that controls the brake device 2. A power supply unit that supplies drive power to the motor 3 and a motor control unit that controls the motor 3 are not shown in FIG. 1. The motor 3 may be an AC motor or a DC motor. Machines in which the motor 3 may be installed include, for example, machine tools, robots, forging machines, injection molding machines, industrial machines, various electrical appliances, trains, automobiles, and aircraft.

[0017] Prior to describing the brake control device 1 according to the first embodiment of the present disclosure, the structure of a non-excitation actuated brake device 2 will be described with reference to Figures 2A and 2B. Figure 2A is a cross-sectional view showing the structure of a non-excitation actuated brake device, illustrating a state in which a brake is actuated on a motor. Figure 2B is a cross-sectional view showing the structure of a non-excitation actuated brake device, illustrating a state in which the brake is released from the motor. The brake devices shown in Figures 2A and 2B can also be applied to the first to sixth embodiments.

[0018] 2A and 2B, in the non-excitation actuation type brake device 2, a friction plate 111 is disposed between an armature 112 and an end plate 113. A hub 122 is splined to the friction plate 111, and the hub 122 and the shaft 121 of the motor 3 are integrated by shrink fitting, so that the friction plate 111 also rotates in conjunction with the rotation of the shaft 121 of the motor 3. The end plate 113 and a spacer 117 are connected by a bolt 118, and the armature 112 is connected to the spacer 117 so as to be movable toward and away from the friction plate 111. A spring 114 and a brake coil 115 are provided within the core 116. As shown in FIG. 2A, in a non-excited state where no voltage is applied to the brake coil 115, the armature 112 is strongly pressed against the friction plate 111 by the elastic force of the spring 114, and the friction plate 111 is sandwiched between the armature 112 and the end plate 113 and cannot rotate. As a result, the shaft 121 of the motor 3 coupled to the friction plate 111 cannot rotate either, and the motor 3 is braked. On the other hand, as shown in FIG. 2B, in an excited state where a voltage is applied to the brake coil 115, an electromagnetic force that overcomes the elastic force of the spring 114 that has been pressing the armature 112 against the friction plate 111 is generated in the core 116, and this attracts the armature 112 to the core 116, and the friction plate 111 is released from contact with the armature 112 and the end plate 113. As a result, the friction plate 111 and therefore the shaft 121 of the motor 3 can freely rotate, and the brake on the motor 3 is released.

[0019] The brake device 2 is controlled by a brake control device 1. The brake control device 1 according to the first embodiment of the present disclosure includes a power source 11, a brake control unit 12, an opening / closing unit 13, a state detection unit 14, an abnormality detection unit 15, and a power supply control unit 16.

[0020] The power supply 11 is a power supply whose DC output voltage is controllable (i.e., a power supply having a variable output), and is controlled to output a voltage or not output a voltage according to a power supply control signal CTRP received from the power supply control unit 16. The power supply 11 is configured using, for example, a chopper circuit and a switching element. As an example, when the power supply 11 receives an output-on signal as the power supply control signal CTRP, the power supply 11 outputs a DC voltage of, for example, 24 V. Note that, in the example shown in FIG. 1, the value of the DC voltage when the output is on is set to 24 V, but other voltage values ​​(for example, 15 V, 12 V, 5 V, etc.) may also be used. Furthermore, when the power supply 11 receives an output-off signal as the power supply control signal CTRP, for example, the power supply 11 does not output a DC voltage, i.e., the DC output voltage of the power supply 11 is 0 V. As an alternative example, when the power supply 11 receives an output-off signal as the power supply control signal CTRP, the power supply 11 may output a voltage less than the voltage that excites the brake coil 115.

[0021] The opening / closing unit 13 is connected in series to the brake coil 115 of the brake device 2, and opens and closes the electric path between the power source 11 and the brake device 2 in response to the received brake control signal. In the first embodiment, the opening / closing unit 13 has at least one positive side opening / closing switch that opens and closes the electric path between the positive terminal of the power source 11 and the positive terminal of the brake device 2, and at least one negative side opening / closing switch that opens and closes the electric path between the negative terminal of the power source 11 and the negative terminal of the brake device 2. In the example shown in FIG. 1, as an example, the opening / closing unit 13 has one positive side opening / closing switch 21A and one negative side opening / closing switch 21B. In the example shown in FIG. 1, one positive side opening / closing switch and one negative side opening / closing switch are provided, but as a modified example, two or more of each may be provided. For example, the positive side opening / closing switch may be configured by two opening / closing switches connected in series, and in this case, the two opening / closing switches are connected in series to receive the same brake control signal BS. A In addition, for example, the negative side switch may be configured with three switches connected in series. In this case, the three switches are controlled by the same brake control signal BS B Opening and closing is controlled by.

[0022] As an example, the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are normally open switches. Examples of the semiconductor switching elements constituting the positive side opening / closing switch 21A and the negative side opening / closing switch 21B include FETs, IGBTs, thyristors, GTOs (Gate Turn-OFF thyristors), transistors, etc., but other semiconductor switching elements may also be used. An FET has a gate, a drain, and a source as its terminals. A thyristor and a GTO have a gate, an anode, and a cathode as its terminals. A transistor has a base, an emitter, and a collector as its terminals. Below, a case where the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are constituted by FETs will be described. Note that, when the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are constituted by thyristors and GTOs, the "gate" is replaced with the "base", the "drain" is replaced with the "anode", and the "source" is replaced with the "cathode", and each embodiment of the present disclosure is applied. Furthermore, when the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are configured with transistors, the "gate" is replaced with the "base", the "drain" is replaced with the "collector", and the "source" is replaced with the "emitter", and each embodiment of the present disclosure is applied.

[0023] In order to remove momentary high voltages such as switching surges and noise of the switching unit 13, a surge absorber 42 is connected between the input terminals of the brake device 2 (i.e., between the positive and negative terminals of the brake device 2) so as to be connected in parallel to the brake device 2.

[0024] The brake control unit 12 generates a brake control signal BS for opening and closing the positive side opening / closing switch 21A and the negative side opening / closing switch 21B in the opening / closing unit 13. A and B.S. B The brake control signal BS output from the brake control unit 12 is A and B.S. Bis sent to the positive side switch 21A and the negative side switch 21B in the opening / closing unit 13 and to the abnormality detection unit 15. The control process executed in the brake control device 1 according to the first embodiment of the present disclosure is divided into three processes: brake activation process, brake release preparation process, and brake release process. A and B.S. B are sent to the positive side opening / closing switch 21A and the negative side opening / closing switch 21B. Details of the brake activation process, the brake release preparation process, and the brake release process in the brake control device 1 will be described later.

[0025] The state detection unit 14 detects the potential state of the electric path between the opening / closing unit 13 and the brake device 2 during the execution of each of the brake activation process, the brake release preparation process, and the brake release process, and outputs a state detection signal indicating this potential state. In the example shown in Fig. 1, the state detection unit 14 outputs a state detection signal FB A , and a state detection signal FB indicating the potential state of the electric path between the drain of the negative side switch 21B in the switching unit 13 and the negative terminal of the brake device 2. B The state detection signal, which indicates the potential state of the electric path between the opening / closing unit 13 and the brake device 2, detected by the state detection unit 14, is sent to the abnormality detection unit 15. The state detection unit 14 outputs a state detection signal FB AIn order to generate the voltage, the state detection unit 14 has, for example, a photocoupler 41A, voltage dividing resistors R1A and R2A, and a pull-up resistor R3A. One end of the voltage dividing resistor R1A is connected to an electric path connecting the source of the positive side opening / closing switch 21A and the positive terminal of the brake device 2, and the other end of the voltage dividing resistor R1A is connected to one end of the voltage dividing resistor R2A. The other end of the voltage dividing resistor R2A is grounded. A light emitting element in the photocoupler 41A is connected in parallel to the voltage dividing resistor R2A. A pull-up resistor R3A is connected to one end of the light receiving element in the photocoupler 41A, and the other end of the light receiving element in the photocoupler 41A is grounded. The state detection unit 14 also outputs a state detection signal FB B In order to generate the signal, for example, the photocoupler 41B includes a photocoupler 41B, voltage-dividing resistors R1B and R2B, and a pull-up resistor R3B. One end of the voltage-dividing resistor R1B is connected to an electric path connecting the negative terminal of the brake device 2 and the drain of the negative-side open-close switch 21B, and the other end of the voltage-dividing resistor R1B is connected to one end of the voltage-dividing resistor R2B. The other end of the voltage-dividing resistor R2B is grounded. A light-emitting element in the photocoupler 41B is connected in parallel to the voltage-dividing resistor R2B. One end of the light-receiving element in the photocoupler 41B is connected to a pull-up resistor R3B, and the other end of the light-receiving element in the photocoupler 41B is grounded. In the example shown in FIG. 1, the state detection unit 14 is configured with a photocoupler and various resistors. However, as an alternative, the state detection unit 14 may be configured with a power supply that outputs a reference voltage for distinguishing between a High state and a Low state (instead of a power supply, the reference voltage may be generated by a method such as resistor division), and a comparator that compares the reference voltage with the voltage applied to the voltage dividing resistor R2A or R2B, and outputs a High signal or a Low signal based on the result of the comparison.

[0026] The abnormality detection unit 15 detects whether or not an abnormality has occurred based on a combination of the contents of the brake control signal and the contents of the state detection signal. The abnormality detection unit 15 detects whether or not an abnormality has occurred based on a combination of the contents of the brake control signal and the contents of the state detection signal during execution of the brake activation process and during execution of the brake release preparation process. The detection result by the abnormality detection unit 15 is sent to the power supply control unit 16. Details of the abnormality detection process by the abnormality detection unit 15 will be described later.

[0027] The abnormalities detected by the abnormality detection unit 15 include a short circuit failure of the positive side opening / closing switch 21A, a short circuit failure of the negative side opening / closing switch 21B, a short circuit between a cable constituting an electric path from the source of the positive side opening / closing switch 21A to the positive terminal of the brake device 2 and an external circuit, a short circuit between a cable constituting an electric path from the negative terminal of the brake device 2 to the drain of the negative side opening / closing switch 21B and an external circuit, and a failure of the state detection unit 14. For example, if the positive side opening / closing switch 21A does not respond to an open command received due to a failure of the drive circuit of the positive side opening / closing switch 21A and the positive side opening / closing switch 21A remains in a closed state, the failure can be regarded as a "short circuit failure of the positive side opening / closing switch 21A". Similarly, if the negative side opening / closing switch 21B does not respond to an open command received due to a failure of the drive circuit of the negative side opening / closing switch 21B and the negative side opening / closing switch 21B remains in a closed state, the failure can be regarded as a "short circuit failure of the negative side opening / closing switch 21B".

[0028] Moreover, the abnormality detection unit 15 has a function of outputting an alarm signal when an abnormality is detected. The alarm signal output from the abnormality detection unit 15 is sent to, for example, a display unit (not shown), and the display unit displays, for example, to notify an operator of an "abnormality". Examples of the display unit include a standalone display device, a display device attached to the motor drive device 100, a display device attached to a higher-level control device (not shown), and a display device attached to a personal computer and a mobile terminal. For example, the alarm signal output from the abnormality detection unit 15 is sent to a light-emitting device (not shown), such as an LED or a lamp, and the light-emitting device notifies an operator of an "abnormality" by emitting light when receiving the alarm signal. For example, the alarm signal output from the abnormality detection unit 15 is sent to, for example, an audio device (not shown), and the audio device notifies an operator of an "abnormality" by emitting a sound, such as a voice, a speaker, a buzzer, or a chime, when receiving the alarm signal. This allows the operator to reliably and easily grasp the occurrence of an abnormality. For example, an operator can easily take measures such as replacing a part related to the abnormality or removing the cause of the abnormality. In addition, the alarm signal output from the abnormality detection unit 15 may be used for emergency stop processing of the motor drive device 100.

[0029] During execution of the brake activation process, the brake release preparation process, and the brake release process, the power supply control unit 16 outputs an output on signal that controls the power supply 11 to output a voltage unless the occurrence of an abnormality is detected by the abnormality detection unit 15, and outputs an output off signal that controls the power supply 11 not to output a voltage if the occurrence of an abnormality is detected by the abnormality detection unit 15. As an alternative example, during execution of the brake activation process and the brake release preparation process, the power supply control unit 16 may output an output off signal regardless of whether or not the abnormality detection unit 15 detects an abnormality.

[0030] An arithmetic processing device (processor) is provided in the brake control device 1. The arithmetic processing device has a brake control unit 12, an abnormality detection unit 15, and a power supply control unit 16. Each of these units in the arithmetic processing device is a functional module realized by, for example, a computer program executed on the processor. For example, when the brake control unit 12, the abnormality detection unit 15, and the power supply control unit 16 are constructed in the form of a computer program, the arithmetic processing device can be operated in accordance with the computer program to realize the functions of each unit. The computer program for executing each process of the brake control unit 12, the abnormality detection unit 15, and the power supply control unit 16 may be provided in a form recorded on a computer-readable recording medium such as a semiconductor memory, a magnetic recording medium, or an optical recording medium. Alternatively, the brake control unit 12, the abnormality detection unit 15, and / or the power supply control unit 16 may be realized as a semiconductor integrated circuit in which a computer program for realizing the function of each unit is written.

[0031] Next, the brake control process and the state detection process in the brake control device 1 according to the first embodiment of the present disclosure will be described.

[0032] Fig. 3A is a diagram for explaining each signal and brake state in a normal state in the brake control device according to the first embodiment of the present disclosure, and shows a table showing each signal and brake state. Fig. 3B is a diagram for explaining each signal and brake state in a normal state in the brake control device according to the first embodiment of the present disclosure, and shows a timing chart showing each signal and brake state. Note that the "brake control signal" is written as "brake signal" in Figs. 3A and 3B to simplify the drawings.

[0033] In the first embodiment of the present disclosure, the control process executed in the brake control device 1 is divided into three processes: brake activation process, brake release preparation process, and brake release process. A state in which the brake device 2 applies a brake to the motor 3 is realized by executing the brake activation process. A state in which the brake device 2 applies a brake to the motor 3 is released by executing the brake release process. When releasing the brake applied to the motor 3, the brake activation process is terminated and the brake release preparation process is executed, and then the brake release preparation process is terminated and the brake release process is executed. When applying the brake to the motor 3 from a state in which the brake to the motor 3 is released, the brake release process is terminated and the brake activation process is executed.

[0034] The brake activation process, the brake release preparation process, and the brake release process executed in the brake control device 1 in the first embodiment will be described in more detail below. In the following description, as an example, the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are normally open switches.

[0035] In the brake activation process, the brake control unit 12 generates a brake control signal BS that controls the positive side opening / closing switch 21A and the negative side opening / closing switch 21B to open. A and B.S. B Since the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are normally open switches, the brake control unit 12 outputs a brake control signal BS A and outputs a low signal as a brake control signal BS BWhen there is no abnormality in the positive side opening / closing switch 21A, the negative side opening / closing switch 21B, or the devices related thereto, the abnormality detection unit 15 does not detect the occurrence of an abnormality, so the power supply control unit 16 outputs an output-on signal to the power supply 11, and therefore a DC voltage (a DC voltage of 24 V in the example shown in FIG. 1) is output from the power supply 11. Since the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are opened by the brake activation process, the electric path from the positive terminal of the power supply 11 through the brake device 2 to the negative terminal of the power supply 11 is interrupted. Therefore, when there is no abnormality in the positive side opening / closing switch 21A, the negative side opening / closing switch 21B, or the devices related thereto, the brake control unit 12 executes the brake activation process, so that the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. 2A, the armature 112 is pressed strongly against the friction plate 111 by the elastic force of the spring 114, and the friction plate 111 is sandwiched between the armature 112 and the end plate 113 and cannot rotate, and therefore the shaft 121 of the motor 3 coupled to the friction plate 111 cannot rotate either, and the motor 3 is braked. Also, since no current flows through the voltage dividing resistors R1A and R2A and the voltage dividing resistors R1B and R2B in the state detection unit 14, the light emitting elements in the photocouplers 41A and 41B do not emit light, and therefore the output sides of the photocouplers 41A and 41B are High. Therefore, the state detection signal FB A and a state detection signal FB indicating the potential state of the electric path between the drain of the negative side open / close switch 21B and the negative terminal of the brake device 2. B Both will be High.

[0036] The brake release preparation process is executed between the brake application process and the brake release process when the brake application process is switched to the brake release process. In the brake release preparation process, the brake control unit 12 outputs a brake control signal BS that controls the positive side opening / closing switch 21A to close and the negative side opening / closing switch 21B to open. A and B.S. BSince the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are normally open switches, the brake control unit 12 outputs a brake control signal BS A and outputs a high signal as a brake control signal BS B When there is no abnormality in the positive side opening / closing switch 21A, the negative side opening / closing switch 21B, or the devices related thereto, the abnormality detection unit 15 does not detect the occurrence of an abnormality, so the power supply control unit 16 outputs an output-on signal to the power supply 11, and therefore a DC voltage (a DC voltage of 24 V in the example shown in FIG. 1) is output from the power supply 11. Since the positive side opening / closing switch 21A is closed but the negative side opening / closing switch 21B is open, the electric path from the positive terminal of the power supply 11 through the brake device 2 to the negative terminal of the power supply 11 is interrupted. Therefore, when there is no abnormality in the positive side opening / closing switch 21A, the negative side opening / closing switch 21B, or the devices related thereto, the brake control unit 12 executes the brake release preparation process, so that the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. 2A, the armature 112 is strongly pressed against the friction plate 111 by the elastic force of the spring 114, and the friction plate 111 is sandwiched between the armature 112 and the end plate 113 and cannot rotate, and therefore the shaft 121 of the motor 3 coupled to the friction plate 111 cannot rotate either, and the motor 3 is braked. Also, the electric path from the positive terminal of the power source 11 through the positive side open / close switch 21A and the brake device 2 to the drain of the negative side open / close switch 21B has the same potential as the voltage output from the positive terminal of the power source 11 (24V in the example shown in FIG. 1). Therefore, current flows through the voltage dividing resistors R1A and R2A and the voltage dividing resistors R1B and R2B in the state detection unit 14, so that the light emitting elements in the photocouplers 41A and 41B emit light, and the output sides of the photocouplers 41A and 41B become Low. Therefore, the state detection signal FB indicating the potential state of the electric path between the source of the positive side opening / closing switch 21A and the positive terminal of the brake device 2 is A and a state detection signal FB indicating the potential state of the electric path between the drain of the negative side open / close switch 21B and the negative terminal of the brake device 2. BBoth will be Low.

[0037] In the brake release process, the brake control unit 12 outputs a brake control signal BS to control the positive side opening / closing switch 21A and the negative side opening / closing switch 21B to close. A and B.S. B Since the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are normally open switches, the brake control unit 12 outputs a brake control signal BS A and outputs a high signal as a brake control signal BS BWhen there is no abnormality in the positive side opening / closing switch 21A, the negative side opening / closing switch 21B, or the devices related thereto, the abnormality detection unit 15 does not detect the occurrence of an abnormality, so the power supply control unit 16 outputs an output-on signal to the power supply 11, and therefore a DC voltage (a DC voltage of 24 V in the example shown in FIG. 1) is output from the power supply 11. Since the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are closed by the brake release process, an electric path is formed from the positive terminal of the power supply 11 through the brake device 2 to the negative terminal of the power supply 11. Therefore, when there is no abnormality in the positive side opening / closing switch 21A, the negative side opening / closing switch 21B, or the devices related thereto, the brake control unit 12 executes the brake release process, and the voltage of the power supply 11 is applied to the brake coil 115 of the brake device 2. 2B, an electromagnetic force that overcomes the elastic force of the spring 114 that presses the armature 112 against the friction plate 111 is generated in the core 116, and the armature 112 is attracted to the core 116, and the friction plate 111 is released from contact with the armature 112 and the end plate 113. As a result, the friction plate 111 and the shaft 121 of the motor 3 can rotate freely, and the brake on the motor 3 is released. In addition, the electric path from the positive terminal of the power source 11 through the positive side open / close switch 21A to the positive terminal of the brake device 2 has the same potential as the voltage output by the positive terminal of the power source 11 (24V in the example shown in FIG. 1). Therefore, a current flows through the voltage dividing resistors R1A and R2A in the state detection unit 14, so that the light emitting element in the photocoupler 41A emits light, and the output side of the photocoupler 41A becomes Low. Therefore, the state detection signal FB indicating the potential state of the electric path between the source of the positive side opening / closing switch 21A and the positive terminal of the brake device 2 is Abecomes Low. Also, the electric potential of the electric path from the negative terminal of the brake device 2 through the negative side opening / closing switch 21B to the negative terminal of the power source 11 is the same as 0V, which is the electric potential of the negative terminal of the power source 11. Therefore, no current flows through the voltage dividing resistors R1B and R2B in the state detection unit 14, so that the light emitting element in the photocoupler 41B does not emit light, and therefore the output side of the photocoupler 41B becomes High. Therefore, the state detection signal FB B will be High.

[0038] When there is no abnormality in the positive side opening / closing switch 21A and the negative side opening / closing switch 21B and the devices related thereto, that is, when normal, the state detection signal FB A and F.B. B The contents of the above are stored in advance in the abnormality detection unit 15 so that they can be used in the abnormality detection process described later.

[0039] Next, an abnormality detection process in the brake control device 1 according to the first embodiment of the present disclosure will be described. In the following description, as an example, the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are normally open switches.

[0040] Fig. 4A is a diagram for explaining each signal and brake state when a short circuit occurs in only the positive opening / closing switch in the brake control device according to the first embodiment of the present disclosure, and shows a table showing each signal and brake state. Fig. 4B is a diagram for explaining each signal and brake state when a short circuit occurs in only the positive opening / closing switch in the brake control device according to the first embodiment of the present disclosure, and shows a timing chart showing each signal and brake state. Note that the "brake control signal" is written as "brake signal" in Figs. 4A and 4B to simplify the drawings.

[0041] In the brake operation process, the brake control unit 12 outputs a brake control signal BSA and outputs a low signal, which is an open command, as a brake control signal BS B At this time, if the positive side opening / closing switch 21A has a short circuit fault, the brake control signal BS A Even if the positive side opening / closing switch 21A is output with a low signal as an open command, the positive side opening / closing switch 21A remains in a closed state. B In response to the output of a Low signal, which is an open command, the negative side open / close switch 21B is opened. Therefore, when the positive side open / close switch 21A has a short circuit failure, during the brake operation processing period, an electric path is formed from the positive terminal of the power source 11 through the positive side open / close switch 21A and the brake device 2 to the drain of the negative side open / close switch 21B. However, since the negative side open / close switch 21B is open, no voltage is applied to the brake device 2. Therefore, the motor 3 is in a brake operation state. The electric path from the positive terminal of the power source 11 through the positive side open / close switch 21A and the brake device 2 to the drain of the negative side open / close switch 21B has the same potential as the voltage output by the positive terminal of the power source 11 (24V in the example shown in FIG. 1). Therefore, a current flows through the voltage dividing resistors R1A and R2A and the voltage dividing resistors R1B and R2B in the state detection unit 14, so that the light emitting elements in the photocouplers 41A and 41B emit light, and therefore the output sides of the photocouplers 41A and 41B are Low. Therefore, the state detection signal FB indicating the potential state of the electric path between the source of the positive side opening / closing switch 21A and the positive terminal of the brake device 2 is A and a state detection signal FB indicating the potential state of the electric path between the drain of the negative side open / close switch 21B and the negative terminal of the brake device 2. B In this way, during the execution of the brake operation process, if there is no abnormality in the positive side opening / closing switch 21A, the negative side opening / closing switch 21B, and the devices related thereto, the state detection signal FB A and status detection signal FB B are both high, but if the positive side open / close switch 21A has a short circuit, the state detection signal FB A and status detection signal FBB During the execution of the brake activation process, the abnormality detection unit 15 detects the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. B In more detail, the abnormality detection unit 15 detects whether an abnormality has occurred based on the combination of the brake control signal BS A and B.S. B are both low and the status detection signal FB A and F.B. B If both are High, it is determined that no abnormality has occurred, and the brake control signal BS A and B.S. B are both low and the status detection signal FB A and F.B. B When both are Low, it is determined that an abnormality has occurred (that is, a short circuit failure of the positive side opening / closing switch 21A). When the abnormality detection unit 15 detects the occurrence of an abnormality during the execution of the brake actuation process, it outputs an alarm signal.

[0042] Fig. 5A is a diagram for explaining each signal and brake state when a short circuit occurs only in the negative open / close switch in a brake control device when a constant voltage is output without output control of the power supply, and shows a table showing each signal and brake state. Fig. 5B is a diagram for explaining each signal and brake state when a short circuit occurs only in the negative open / close switch in a brake control device when a constant voltage is output without output control of the power supply, and shows a timing chart showing each signal and brake state. Note that the "brake control signal" is written as "brake signal" in Figs. 5A and 5B to simplify the drawings.

[0043] 5A and 5B show the signals and brake states when only the negative side switch 21B has a short circuit, assuming that the power source 11 is not an output controllable power source (i.e., a power source having a variable output) but is a power source that outputs a voltage of a constant magnitude (e.g., 24 V). When the positive side switch 21A is normal and the negative side switch 21B has a short circuit, the state detection signal FB A and F.B. B The status detection signal FB A becomes Low and the status detection signal FB B During the brake release preparation process, the brake control signal BS B Although the negative side opening / closing switch 21B outputs a Low signal, which is an open command, as the negative side opening / closing switch 21B has a short circuit failure, the negative side opening / closing switch 21B is closed. Therefore, when the negative side opening / closing switch 21B has a short circuit failure, an electric path is formed from the positive terminal of the power source 11 through the positive side opening / closing switch 21A, the brake device 2, and the negative side opening / closing switch 21B to the negative terminal of the power source 11 during the brake release preparation process. As a result, the voltage of the power source 11 is applied to the brake coil 115 of the brake device 2, and the brake on the motor 3 is released. In this way, if a short circuit failure occurs in the negative side opening / closing switch 21B during the brake release preparation process, the brake is released when it should be activated, which is dangerous. The electric path from the negative terminal of the brake device 2 to the drain of the negative side opening / closing switch 21B has the same potential as 0V, which is the potential of the negative terminal of the power source 11. Therefore, no current flows through the voltage dividing resistors R1B and R2B in the state detection unit 14, so the light emitting element in the photocoupler 41B does not emit light, and the output side of the photocoupler 41B becomes High. Therefore, the state detection signal FB Bbecomes High. On the other hand, the electric path from the positive terminal of the power source 11, via the positive side opening / closing switch 21A, to the positive terminal of the brake device 2 becomes the same potential as the voltage output by the positive terminal of the power source 11 (24 V in the example shown in FIG. 1). Therefore, a current flows through the voltage dividing resistors R1A and R2A in the state detection unit 14, causing the light emitting element of the photocoupler 41A to emit light, and therefore the output side of the photocoupler 41A becomes Low. Therefore, the state detection signal FB A In this way, during the brake release preparation process, if there is no abnormality in the positive side opening / closing switch 21A, the negative side opening / closing switch 21B, and the devices related thereto, the state detection signal FB A and status detection signal FB B are both low, but when only the negative side open / close switch 21B has a short circuit failure, the state detection signal FB A becomes Low and the status detection signal FB B During the brake release preparation process, the abnormality detection unit 15 detects the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. B In more detail, the abnormality detection unit 15 detects whether an abnormality has occurred based on the combination of the brake control signal BS A is High and the brake control signal BS B is Low and the status detection signal FB A and F.B. B When both of the brake control signal BS are low, the brake control unit 12 determines that no abnormality has occurred, and ends the brake release preparation process and executes the brake release process. A is High and the brake control signal BS B is Low and the status detection signal FB A is Low and the status detection signal FB B If the signal is High, it is determined that an abnormality has occurred (i.e., a short circuit failure of the negative side open / close switch 21B).

[0044] If a short-circuit failure occurs in the negative side opening / closing switch 21B during the brake release preparation process period, the brake on the motor 3 may be released, which may lead to a dangerous state, so the time period for executing the brake release preparation process may be set to a time shorter than the response time of the brake device 2 to a brake command. By setting the time period for executing the brake release preparation process in this manner, even if a short-circuit failure occurs in the negative side opening / closing switch 21B, it is possible to detect the short-circuit failure of the negative side opening / closing switch 21B while preventing the brake of the brake device 2 on the motor 3 from being released.

[0045] Fig. 6A is a diagram for explaining each signal and brake state when a short circuit occurs only in the negative-side open / close switch in the brake control device having an output-controllable power supply according to the first embodiment of the present disclosure, and shows a table showing each signal and brake state. Fig. 6B is a diagram for explaining each signal and brake state when a short circuit occurs only in the negative-side open / close switch in the brake control device having an output-controllable power supply according to the first embodiment of the present disclosure, and shows a timing chart showing each signal and brake state. Note that the "brake control signal" is written as "brake signal" in Figs. 6A and 6B to simplify the drawings.

[0046] As described with reference to FIGS. 5A and 5B, the abnormality detection unit 15 detects the state detection signal FB A and F.B. B are both high, and the brake release preparation process is in progress. A is Low and the status detection signal FB Bis High, it is determined that an abnormality has occurred (i.e., a short circuit failure of the negative side opening / closing switch 21B). In this case, if a short circuit failure occurs in the negative side opening / closing switch 21B during the execution of the brake release preparation process, the brake is released when it should be activated, so the abnormality detection unit 15 outputs an alarm signal. Also, as shown in FIG. 6A, when the abnormality detection unit 15 detects an abnormality during the brake release preparation process period, the power supply control unit 16 outputs an output off signal as a power supply control signal CTRP for the output controllable power supply 11, which controls the power supply 11 not to output a voltage. As a result, the power supply 11 does not output a DC voltage, that is, the DC output voltage of the power supply 11 becomes 0V, that is, the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked. This makes it possible to avoid the brake being released when an abnormality occurs (when a short circuit failure occurs in the negative side opening / closing switch 21B).

[0047] Fig. 7A is a diagram for explaining each signal and brake state when a short circuit occurs only in the negative side open / close switch in a brake control device having a recovery sequence of a brake actuation process according to the first embodiment of the present disclosure, and shows a table showing each signal and brake state. Fig. 7B is a diagram for explaining each signal and brake state when a short circuit occurs only in the negative side open / close switch in a brake control device having a recovery sequence of a brake actuation process according to the first embodiment of the present disclosure, and shows a timing chart showing each signal and brake state. Note that the "brake control signal" is written as "brake signal" in Figs. 7A and 7B to simplify the drawings.

[0048] As described with reference to FIGS. 5A and 5B, the abnormality detection unit 15 detects the state detection signal FB A and F.B. B are both high, and the brake release preparation process is in progress. A is Low and the status detection signal FB Bis High, it is determined that an abnormality has occurred (i.e., a short circuit failure of the negative side opening / closing switch 21B). In this case, the brake control unit 12 ends the brake release preparation process and executes the brake activation process instead of the brake release process. Even if a short circuit failure has occurred in the negative side opening / closing switch 21B, at least the positive side opening / closing switch 21A is opened by the brake control unit 12 executing the brake activation process, so that the voltage of the power source 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked. This makes it possible to avoid the brake being released when an abnormality has occurred (when a short circuit failure has occurred in the negative side opening / closing switch 21B).

[0049] Fig. 8A is a diagram for explaining each signal and brake state when a short circuit occurs in both the positive side open / close switch and the negative side open / close switch in a brake control device when a constant voltage is output without output control of the power supply, and shows a table showing each signal and brake state. Fig. 8B is a diagram for explaining each signal and brake state when a short circuit occurs in both the positive side open / close switch and the negative side open / close switch in a brake control device when a constant voltage is output without output control of the power supply, and shows a timing chart showing each signal and brake state. Note that the "brake control signal" is written as "brake signal" in Figs. 8A and 8B to simplify the drawings.

[0050] 8A and 8B show signals and brake states when both the positive side switch 21A and the negative side switch 21B have a short circuit, assuming that the power supply 11 is not an output controllable power supply (i.e., a power supply with a variable output) but is a power supply that outputs a voltage of a constant magnitude (e.g., 24 V). When both the positive side switch 21A and the negative side switch 21B have a short circuit, the brake control signal BS for the positive side switch 21A is generated by the brake activation process. A and outputs a low signal which is an open command as a brake control signal BS BEven if the power supply 11 outputs a Low signal, which is an open command, as the switch 21A, both the positive side switch 21A and the negative side switch 21B are closed. Therefore, an electric path is formed from the positive terminal of the power supply 11 through the positive side switch 21A, the brake device 2, and the negative side switch 21B to the negative terminal of the power supply 11. As a result, the voltage of the power supply 11 is applied to the brake coil 115 of the brake device 2, and the brake for the motor 3 is released. In this way, if a short circuit failure occurs in both the positive side switch 21A and the negative side switch 21B during the execution of the brake activation process, the brake is released when it should be activated, which is dangerous. The electric path from the positive terminal of the power supply 11 through the positive side switch 21A to the positive terminal of the brake device 2 is at the same potential as the voltage output by the positive terminal of the power supply 11 (24 V in the example shown in FIG. 1). As a result, a current flows through the voltage dividing resistors R1A and R2A in the state detection unit 14, causing the light emitting element of the photocoupler 41A to emit light, and therefore the output side of the photocoupler 41A becomes low. Therefore, the state detection signal FB A becomes Low. On the other hand, the electric potential of the electric path from the negative terminal of the brake device 2 to the drain of the negative side opening / closing switch 21B is the same as 0V, which is the electric potential of the negative terminal of the power source 11. Therefore, since no current flows through the voltage dividing resistors R1B and R2B in the state detection unit 14, the light emitting element in the photocoupler 41B does not emit light, and therefore the output side of the photocoupler 41B becomes High. Therefore, the state detection signal FB B In this way, during the brake operation process, if there is no abnormality in the positive side opening / closing switch 21A, the negative side opening / closing switch 21B, or the devices related thereto, the state detection signal FB A and status detection signal FB B are both high, but if both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are short-circuited, the state detection signal FB A becomes Low and the status detection signal FB B becomes High.

[0051] In addition, when both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are short-circuited, the brake control signal BS A and outputs a High signal, which is an open command, as a brake control signal BS B Even if the power supply 11 outputs a Low signal, which is an open command, as the switch 21A, both the positive side switch 21A and the negative side switch 21B are closed. Therefore, an electric path is formed from the positive terminal of the power supply 11 through the positive side switch 21A, the brake device 2, and the negative side switch 21B to the negative terminal of the power supply 11. As a result, the voltage of the power supply 11 is applied to the brake coil 115 of the brake device 2, and the brake for the motor 3 is released. In this way, if a short circuit failure occurs in both the positive side switch 21A and the negative side switch 21B during the execution of the brake release preparation process, the brake is released when it should be activated, which is dangerous. The electric path from the positive terminal of the power supply 11 through the positive side switch 21A to the positive terminal of the brake device 2 is at the same potential as the voltage output by the positive terminal of the power supply 11 (24 V in the example shown in FIG. 1). As a result, a current flows through the voltage dividing resistors R1A and R2A in the state detection unit 14, causing the light emitting element of the photocoupler 41A to emit light, and therefore the output side of the photocoupler 41A becomes low. Therefore, the state detection signal FB A becomes Low. On the other hand, the electric potential of the electric path from the negative terminal of the brake device 2 to the drain of the negative side opening / closing switch 21B is the same as 0V, which is the electric potential of the negative terminal of the power source 11. Therefore, since no current flows through the voltage dividing resistors R1B and R2B in the state detection unit 14, the light emitting element in the photocoupler 41B does not emit light, and therefore the output side of the photocoupler 41B becomes High. Therefore, the state detection signal FB BIn this way, during the brake release preparation process, if there is no abnormality in the positive side opening / closing switch 21A, the negative side opening / closing switch 21B, and the devices related thereto, the state detection signal FB A and status detection signal FB B are both high, but if both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are short-circuited, the state detection signal FB A becomes Low and the status detection signal FB B becomes High.

[0052] In this way, when a short circuit occurs in both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B, the state detection signal FB A and F.B. B This results in a signal state that is different from normal.

[0053] Fig. 9A is a diagram for explaining each signal and brake state when a short circuit occurs in both the positive side open / close switch and the negative side open / close switch in a brake control device having an output controllable power supply according to the first embodiment of the present disclosure, and shows a table showing each signal and brake state. Fig. 9B is a diagram for explaining each signal and brake state when a short circuit occurs in both the positive side open / close switch and the negative side open / close switch in a brake control device having an output controllable power supply according to the first embodiment of the present disclosure, and shows a timing chart showing each signal and brake state. Note that the "brake control signal" is written as "brake signal" in Figs. 9A and 9B to simplify the drawings.

[0054] As described with reference to FIG. 8A and FIG. 8B, when the abnormality detection unit 15 detects an abnormality both during the execution of the brake activation process and during the execution of the brake release preparation process, both the positive side open / close switch 21A and the negative side open / close switch 21B have a short circuit failure, and the brake should be activated by the brake activation process and the brake release preparation process, but is released, so the abnormality detection unit 15 outputs an alarm signal. Also, as shown in FIG. 9A, when the abnormality detection unit 15 detects an abnormality both during the execution of the brake activation process and during the execution of the brake release preparation process, the power supply control unit 16 outputs an output off signal as a power supply control signal CTRP for the output controllable power supply 11, which controls the power supply 11 not to output a voltage. As a result, the power supply 11 does not output a DC voltage, that is, the DC output voltage of the power supply 11 is 0V. Therefore, the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2, and the brake is activated for the motor 3. This makes it possible to prevent the brake from being continuously released when an abnormality occurs (when a short circuit occurs in the positive side opening / closing switch 21A and the negative side opening / closing switch 21B).

[0055] FIG. 10 is a flowchart showing an operation flow until the brake applied to the motor by the brake device is released in the brake control device according to the first embodiment of the present disclosure.

[0056] During the execution of the brake activation process, the brake release preparation process, and the brake release process, the state detection unit 14 outputs a state detection signal FB A , and a state detection signal FB indicating the potential state of the electric path between the drain of the negative side switch 21B in the switching unit 13 and the negative terminal of the brake device 2. B Output.

[0057] In step S101, a brake actuation process is executed. In the brake actuation process, the brake control unit 12 outputs a brake control signal BS for controlling the positive side opening / closing switch 21A and the negative side opening / closing switch 21B to be opened. A and B.S. B Output.

[0058] In step S102, the abnormality detection unit 15 detects the BS of the brake control signal during the execution of the brake application process. A and B.S. B Contents and status detection signal FB A and F.B. B Based on the combination of the contents of the above, the presence or absence of an abnormality (i.e., a short circuit failure of the positive side opening / closing switch 21A) is detected. If an abnormality is detected in step S102, the process proceeds to step S107. On the other hand, if an abnormality is not detected in step S102, the process proceeds to step S103.

[0059] In step S103, the brake control unit 12 judges whether or not a brake release command has been received from a higher-level control device (not shown). Examples of higher-level control devices include a motor control device for controlling the motor 3 that is the braking target of the brake device 2, and a control device that is higher level than the motor control device (e.g., a numerical control device or a robot control device). If it is judged in step S103 that the brake release command has not been received, the process returns to step S101 and continues executing the brake activation process. If it is judged in step S103 that the brake release command has been received, the process proceeds to step S104.

[0060] In step S104, the brake control unit 12 executes a brake release preparation process. In the brake release preparation process, the brake control unit 12 generates a brake control signal BS A and B.S. B Output.

[0061] In step S105, the abnormality detection unit 15 detects the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. B Based on the combination of the contents of the above, the presence or absence of an abnormality (i.e., a short circuit failure of the negative side opening / closing switch 21B) is detected. If an abnormality is detected in step S105, the process proceeds to step S110. On the other hand, if an abnormality is not detected in step S105, the process proceeds to step S106.

[0062] In step S106, a brake release process is executed. In the brake release process, the brake control unit 12 outputs a brake control signal BS that controls the positive side opening / closing switch 21A and the negative side opening / closing switch 21B to close. A and B.S. B In this way, the brake release process in step S106 is executed when no abnormality is detected in step S102 during the brake application process and no abnormality is detected in step S105 during the brake release preparation process, so that the brakes can be released safely.

[0063] If an abnormality is detected in step S105, in step S110, the power supply control unit 16 outputs an output-off signal as a power supply control signal CTRP for the output-controllable power supply 11, which controls the power supply 11 not to output a voltage. As a result, the power supply 11 does not output a DC voltage, that is, the DC output voltage of the power supply 11 becomes 0V, that is, the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked. This makes it possible to prevent the brake from being released when an abnormality occurs.

[0064] In step S111, the abnormality detection unit 15 outputs an alarm signal to notify an operator of the occurrence of an abnormality.

[0065] In step S102, when the abnormality detection unit 15 detects the occurrence of an abnormality during execution of the brake actuation process, in step S107, the brake control unit 12 determines whether or not a brake release command has been received from a higher-level control device (not shown).

[0066] If it is determined in step S107 that the brake release command has not been received, the process proceeds to step S111. The abnormality detected in step S102, which was executed before step S107, is a short-circuit failure of the positive side opening / closing switch 21A. As described with reference to Fig. 4A and Fig. 4B, even if there is a short-circuit failure of the positive side opening / closing switch 21A, the brake is activated by the brake device 2, so safety is ensured. However, in order to notify the operator of the occurrence of an abnormality, in step S111, the abnormality detection unit 15 outputs an alarm signal.

[0067] If it is determined in step S107 that the brake release command has been received, the process proceeds to step S108. In step S108, the brake control unit 12 executes a brake release preparation process. In the brake release preparation process, the brake control unit 12 outputs a brake control signal BS A and B.S. B Output.

[0068] In step S109, the abnormality detection unit 15 detects the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. B Based on the combination of the contents of the above, the presence or absence of an abnormality (that is, a short circuit failure of the negative side open-close switch 21B) is detected.

[0069] If an abnormality is detected in step S109, a short circuit failure has occurred in both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B described with reference to Figs. 8A and 8B and Figs. 9A and 9B. Therefore, the power supply 11 does not output a DC voltage, that is, the DC output voltage of the power supply 11 is 0V, and the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked. That is, it is possible to prevent the brake from being released when an abnormality occurs. In step S111 following step S110, the abnormality detection unit 15 outputs an alarm signal to notify the operator of the abnormality.

[0070] If no abnormality is detected in step S109, only a short-circuit failure has occurred in the positive side opening / closing switch 21A as described with reference to Figures 4A and 4B. In this case, the brake of the brake device 2 is operating and safety is ensured. However, in order to notify the operator of the occurrence of an abnormality, in step S111, the abnormality detection unit 15 outputs an alarm signal.

[0071] As described above, according to the brake control device 1 according to the first embodiment of the present disclosure, only when no abnormality occurs, it is possible to release the brake applied by the brake device 2 applied to the motor 3. Furthermore, even if an abnormality occurs when releasing the brake applied by the brake device 2 applied to the motor 3, it is possible to avoid a situation in which the brake is released.

[0072] Next, a second embodiment of the present disclosure will be described. The power supply 11 in the first embodiment is a power supply whose output can be controlled based on a power supply control signal CTRP from the power supply control unit 16, and therefore has a higher probability of failure than a power supply that always outputs a constant voltage. The second embodiment of the present disclosure makes it possible to detect the occurrence of an abnormality in the power supply 11. The occurrence of an abnormality in the power supply can be detected by a first power supply inspection process executed between the brake activation process and the brake release preparation process, or a second power supply inspection process executed between the brake release process and the brake activation process.

[0073] FIG. 11 is a diagram illustrating each signal and brake state when the power supply is normal in a brake control device having a first power supply inspection function according to a second embodiment of the present disclosure. Also, FIG. 12 is a diagram illustrating each signal and brake state when the power supply is abnormal in a brake control device having a first power supply inspection function according to a second embodiment of the present disclosure. For the sake of simplicity, in FIG. 11 and FIG. 12, it is assumed that there is no occurrence of an abnormality such as a short circuit failure of the positive side opening / closing switch 21A and / or the negative side opening / closing switch 21B that may be detected during the execution of the brake activation process and the brake release preparation process. Also, in FIG. 11 and FIG. 12, the "brake control signal" is written as "brake signal" for the sake of simplicity of the drawings.

[0074] The first power supply inspection process is executed before executing the brake release preparation process when transitioning from the brake activation process to the brake release preparation process. In the first power supply inspection process, the power supply control unit 16 outputs an output off signal as the power supply control signal CTRP to the power supply 11, and the brake control unit 12 outputs a brake control signal BS A and B.S. B Since the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are normally open switches, the brake control unit 12 outputs a brake control signal BS A and outputs a high signal as a brake control signal BSB A Low signal is output as a

[0075] As shown in FIG. 11, if the power supply 11 is normal, during the first power supply inspection processing period, the power supply 11 does not output a DC voltage in response to an output off signal received from the power supply control unit 16, that is, the DC output voltage of the power supply 11 is 0V. Therefore, the electric path from the positive terminal of the power supply 11 through the positive side opening / closing switch 21A to the positive terminal of the brake device 2 has the same potential as the output voltage of the positive terminal of the power supply 11 (0V in the example shown in FIG. 1). Therefore, since a current flows through the voltage dividing resistors R1A and R2A and the voltage dividing resistors R1B and R2B in the state detection unit 14, the light emitting elements in the photocouplers 41A and 41B do not emit light, and therefore the output sides of the photocouplers 41A and 41B are High. Therefore, the state detection signal FB indicating the electric potential state of the electric path between the source of the positive side opening / closing switch 21A and the positive terminal of the brake device 2 is A becomes High. Also, the electric potential of the electric path from the negative terminal of the brake device 2 through the negative side opening / closing switch 21B to the negative terminal of the power source 11 is the same as 0V, which is the electric potential of the negative terminal of the power source 11. Therefore, since no current flows through the voltage dividing resistors R1B and R2B in the state detection unit 14, the light emitting element in the photocoupler 41B does not emit light, and therefore the output side of the photocoupler 41B becomes High. Therefore, the state detection signal FB B will be High.

[0076] The state detection signal FB in the first power supply inspection process when the power supply 11 is normal A and F.B. B The contents of the above are stored in advance in the abnormality detection unit 15 so that they can be used in the abnormality detection process for the power supply 11.

[0077] When a fault occurs in the power supply 11, such as "continuing to output voltage without responding to an output-off signal," the power supply 11 continues to output a DC voltage (for example, 24 V) even if it receives an output-off signal from the power supply control unit 16, as shown in FIG. 12. Therefore, the electric path from the positive terminal of the power supply 11 through the positive side opening / closing switch 21A to the positive terminal of the brake device 2 has the same potential as the voltage output by the positive terminal of the power supply 11 (24 V in the example shown in FIG. 1). Therefore, current flows through the voltage dividing resistors R1A and R2A and the voltage dividing resistors R1B and R2B in the state detection unit 14, so that the light emitting elements in the photocouplers 41A and 41B emit light, and therefore the output sides of the photocouplers 41A and 41B become Low. Therefore, the state detection signal FB indicating the electric potential state of the electric path between the source of the positive side opening / closing switch 21A and the positive terminal of the brake device 2 is generated. A and a state detection signal FB indicating the potential state of the electric path between the drain of the negative side open / close switch 21B and the negative terminal of the brake device 2. B Both will be Low.

[0078] In this way, if the power supply 11 is normal, the status detection signal FB A and F.B. B are both high, but if there is an abnormality in the power supply 11, the status detection signal FB A and F.B. B Therefore, during the first power supply inspection process, the abnormality detection unit 15 detects that the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. B Based on a combination of the contents of the state detection signal FB and the contents of the power supply control signal CTRP, the abnormality detection unit 15 detects whether an abnormality has occurred in the power supply 11. In the example shown in FIG. 1, the abnormality detection unit 15 detects whether an abnormality has occurred in the power supply 11 based on the combination of the contents of the state detection signal FB A and F.B. B If both are High, it is determined that there is no abnormality in the power supply 11, and the status detection signal FB A and F.B. BIf both of these are low, it is determined that an abnormality has occurred in the power supply 11. When the abnormality detection unit 15 detects an abnormality in the power supply 11, it outputs an alarm signal. The alarm signal output from the abnormality detection unit 15 is sent to, for example, a display unit (not shown), and the display unit displays, for example, a display that notifies an operator of an "abnormality in the power supply". Examples of the display unit include a standalone display device, a display device attached to the motor drive device 100, a display device attached to a higher-level control device (not shown), and a display device attached to a personal computer and a mobile terminal. In addition, for example, the alarm signal output from the abnormality detection unit 15 is sent to a light-emitting device (not shown), such as an LED or a lamp, and the light-emitting device emits light when receiving the alarm signal to notify the operator of the "abnormality". In addition, for example, the alarm signal output from the abnormality detection unit 15 is sent to, for example, an audio device (not shown), and the audio device notifies the operator of the "abnormality in the power supply" by emitting a sound, such as a voice, a speaker, a buzzer, or a chime, when receiving the alarm signal. This allows the worker to easily and reliably recognize the occurrence of an abnormality in the power supply. The worker can easily take action, such as replacing the power supply. The alarm signal output from the abnormality detection unit 15 may be used for emergency shutdown processing of the motor drive device 100.

[0079] FIG. 13 is a flowchart showing an operation flow when releasing the brake applied to the motor by the brake device in the brake control device according to the second embodiment of the present disclosure.

[0080] During the execution of the brake activation process, the first power supply inspection process, the brake release preparation process, and the brake release process, the state detection unit 14 outputs a state detection signal FB A , and a state detection signal FB indicating the potential state of the electric path between the drain of the negative side switch 21B in the switching unit 13 and the negative terminal of the brake device 2. B Output.

[0081] In step S101, a brake actuation process is executed. In the brake actuation process, the brake control unit 12 outputs a brake control signal BS for controlling the positive side opening / closing switch 21A and the negative side opening / closing switch 21B to be opened. A and B.S. B In addition, the power supply control unit 16 outputs an output on signal to the power supply 11.

[0082] In step S102, the abnormality detection unit 15 detects the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. B Based on the combination of the contents of the above, the presence or absence of an abnormality (i.e., a short circuit failure of the positive side opening / closing switch 21A) is detected. If an abnormality is detected in step S102, the process proceeds to step S107. On the other hand, if an abnormality is not detected in step S102, the process proceeds to step S103.

[0083] In step S103, the brake control unit 12 judges whether or not a brake release command has been received from a higher-level control device (not shown). If it is judged in step S103 that the brake release command has not been received, the process returns to step S101 and continues executing the brake activation process. If it is judged in step S103 that the brake release command has been received, the process proceeds to step S112.

[0084] In step S112, a first power supply inspection process is executed. In the first power supply inspection process, the power supply control unit 16 outputs an output-off signal as a power supply control signal CTRP to the power supply 11, and the brake control unit 12 outputs a brake control signal BS A and B.S. B During the first power supply inspection process, the abnormality detection unit 15 outputs the brake control signal BS A and B.S. B and status detection signal FB A and F.B. BBased on a combination of the contents of this signal and the contents of the power supply control signal CTRP, the presence or absence of an abnormality in the power supply 11 is detected.

[0085] If an abnormality is detected in the power supply 11 in step S112, the process proceeds to step S113. In step S113, the abnormality detection unit 15 outputs an alarm signal to notify the operator of the abnormality in the power supply 11. Thereafter, the process ends.

[0086] If no abnormality in the power supply 11 is detected in step S112, the process proceeds to step S104.

[0087] In step S104, the brake control unit 12 executes a brake release preparation process. In the brake release preparation process, the brake control unit 12 generates a brake control signal BS A and B.S. B Output.

[0088] In step S105, the abnormality detection unit 15 detects the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. B Based on the combination of the contents of the above, the presence or absence of an abnormality (i.e., a short circuit failure of the negative side opening / closing switch 21B) is detected. If an abnormality is detected in step S105, the process proceeds to step S110. On the other hand, if an abnormality is not detected in step S105, the process proceeds to step S106.

[0089] In step S106, a brake release process is executed. In the brake release process, the brake control unit 12 outputs a brake control signal BS that controls the positive side opening / closing switch 21A and the negative side opening / closing switch 21B to close. A and B.S. BIn this way, the brake release process in step S106 is executed when no abnormality is detected in step S102 during the brake application process and no abnormality is detected in step S105 during the brake release preparation process, so that the brakes can be released safely.

[0090] If an abnormality is detected in step S105, in step S110, the power supply control unit 16 outputs an output-off signal as a power supply control signal CTRP for the output-controllable power supply 11, which controls the power supply 11 not to output a voltage. As a result, the power supply 11 does not output a DC voltage, that is, the DC output voltage of the power supply 11 becomes 0V, that is, the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked. This makes it possible to prevent the brake from being released when an abnormality occurs.

[0091] In step S111, the abnormality detection unit 15 outputs an alarm signal to notify an operator of the occurrence of an abnormality.

[0092] In step S102, when the abnormality detection unit 15 detects the occurrence of an abnormality during execution of the brake actuation process, in step S107, the brake control unit 12 determines whether or not a brake release command has been received from a higher-level control device (not shown).

[0093] If it is determined in step S107 that the brake release command has not been received, the process proceeds to step S111. The abnormality detected in step S102, which was executed before step S107, is a short-circuit failure of the positive side opening / closing switch 21A. As described with reference to Figs. 4A and 4B, even if there is a short-circuit failure of the positive side opening / closing switch 21A, the brake is activated by the brake device 2, so safety is ensured. However, in order to notify the operator of the occurrence of an abnormality, in step S111, the abnormality detection unit 15 outputs an alarm signal.

[0094] If it is determined in step S107 that a brake release command has been received, the process proceeds to step S114.

[0095] In step S114, a first power supply inspection process is executed. In the first power supply inspection process, the power supply control unit 16 outputs an output-off signal as a power supply control signal CTRP to the power supply 11, and the brake control unit 12 outputs a brake control signal BS A and B.S. B During the first power supply inspection process, the abnormality detection unit 15 outputs the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. B Based on a combination of the contents of this signal and the contents of the power supply control signal CTRP, the presence or absence of an abnormality in the power supply 11 is detected.

[0096] If an abnormality in the power supply 11 is detected in step S114, the process proceeds to step S111. In step S111, the abnormality detection unit 15 outputs an alarm signal to notify the operator of the abnormality in the power supply 11. Then, the process ends.

[0097] If no abnormality in the power supply 11 is detected in step S114, the process proceeds to step S108. In step S108, a brake release preparation process is executed. In the brake release preparation process, the brake control unit 12 outputs a brake control signal BS A and B.S. B Output.

[0098] In step S109, the abnormality detection unit 15 detects the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. BBased on the combination of the contents of the above, the presence or absence of an abnormality (that is, a short circuit failure of the negative side open-close switch 21B) is detected.

[0099] If an abnormality is detected in step S109, a short circuit failure has occurred in both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B described with reference to Figs. 8A and 8B and Figs. 9A and 9B. Therefore, the power supply 11 does not output a DC voltage, that is, the DC output voltage of the power supply 11 is 0V, and the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked. This makes it possible to prevent the brake from being released when an abnormality occurs. In step S111 following step S110, the abnormality detection unit 15 outputs an alarm signal to notify the operator of the abnormality.

[0100] If no abnormality is detected in step S109, only a short-circuit failure has occurred in the positive side opening / closing switch 21A as described with reference to Figures 4A and 4B. In this case, the brake of the brake device 2 is operating and safety is ensured. However, in order to notify the operator of the occurrence of an abnormality, in step S111, the abnormality detection unit 15 outputs an alarm signal.

[0101] In the brake control device 1 having the first power supply inspection function according to the second embodiment of the present disclosure, an operation flow other than the operation flow described with reference to Fig. 13 may be adopted as the operation flow when transitioning from the brake actuation process to the brake release process via the brake release preparation process. For example, when at least one of the occurrence of an abnormality to be detected during the execution of the brake actuation process by the abnormality detection unit 15, the occurrence of an abnormality to be detected during the execution of the brake release preparation process by the abnormality detection unit 15, and the occurrence of an abnormality in the power supply 11 is not detected, the brake of the brake device 2 can be actuated by a means that does not detect the abnormality (i.e., any one of the positive side opening / closing switch 21A, the negative side opening / closing switch 21B, or the output-controllable power supply 11), so safety is ensured. Therefore, when at least one of the occurrence of an abnormality to be detected during the execution of the brake actuation process by the abnormality detection unit 15, the occurrence of an abnormality to be detected during the execution of the brake release preparation process by the abnormality detection unit 15, and the occurrence of an abnormality in the power supply 11 is not detected, the brake control unit 12 may operate the brake control device 1 according to an operation flow in which the brake release preparation process is terminated and the brake release process is executed.

[0102] Next, the second power supply inspection process will be described.

[0103] FIG. 14 is a diagram illustrating each signal and brake state when the power supply is normal in the brake control device having the second power supply inspection function according to the second embodiment of the present disclosure. Also, FIG. 15 is a diagram illustrating each signal and brake state when the power supply is abnormal in the brake control device having the second power supply inspection function according to the second embodiment of the present disclosure. For the sake of simplicity, in FIG. 14 and FIG. 15, it is assumed that there is no occurrence of an abnormality such as a short circuit failure of the positive side opening / closing switch 21A and / or the negative side opening / closing switch 21B that may be detected during the execution of the brake activation process and the brake release preparation process. Also, in FIG. 14 and FIG. 15, the "brake control signal" is written as "brake signal" for the sake of simplicity.

[0104] The second power supply inspection process is executed before executing the brake activation process when transitioning from the brake release process to the brake activation process. In the second power supply inspection process, the power supply control unit 16 outputs an output off signal as the power supply control signal CTRP to the power supply 11, and the brake control unit 12 outputs a brake control signal BS A and B.S. B Since the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are normally open switches, the brake control unit 12 outputs a brake control signal BS A and outputs a high signal as a brake control signal BS B A Low signal is output as a

[0105] As shown in FIG. 14, if the power supply 11 is normal, during the second power supply inspection processing period, the power supply 11 does not output a DC voltage in response to an output off signal received from the power supply control unit 16, that is, the DC output voltage of the power supply 11 is 0V. Therefore, the electric path from the positive terminal of the power supply 11 through the positive side opening / closing switch 21A to the positive terminal of the brake device 2 has the same potential as the output voltage of the positive terminal of the power supply 11 (0V in the example shown in FIG. 1). Therefore, since a current flows through the voltage dividing resistors R1A and R2A and the voltage dividing resistors R1B and R2B in the state detection unit 14, the light emitting elements in the photocouplers 41A and 41B do not emit light, and therefore the output sides of the photocouplers 41A and 41B are High. Therefore, the state detection signal FB indicating the electric potential state of the electric path between the source of the positive side opening / closing switch 21A and the positive terminal of the brake device 2 is Abecomes High. Also, the electric potential of the electric path from the negative terminal of the brake device 2 through the negative side opening / closing switch 21B to the negative terminal of the power source 11 is the same as 0V, which is the electric potential of the negative terminal of the power source 11. Therefore, since no current flows through the voltage dividing resistors R1B and R2B in the state detection unit 14, the light emitting element in the photocoupler 41B does not emit light, and therefore the output side of the photocoupler 41B becomes High. Therefore, the state detection signal FB B will be High.

[0106] The state detection signal FB in the second power supply inspection process when the power supply 11 is normal. A and F.B. B The contents of the above are stored in advance in the abnormality detection unit 15 so that they can be used in the abnormality detection process for the power supply 11.

[0107] When a fault occurs in the power supply 11, such as "continuing to output voltage without responding to an output-off signal," the power supply 11 continues to output a DC voltage (for example, 24 V) even if it receives an output-off signal from the power supply control unit 16, as shown in FIG. 15. Therefore, the electric path from the positive terminal of the power supply 11 through the positive side opening / closing switch 21A and the brake device 2 to the drain of the negative side opening / closing switch 21B has the same potential as the voltage output by the positive terminal of the power supply 11 (24 V in the example shown in FIG. 1). Therefore, current flows through the voltage dividing resistors R1A and R2A and the voltage dividing resistors R1B and R2B in the state detection unit 14, so that the light emitting elements in the photocouplers 41A and 41B emit light, and the output sides of the photocouplers 41A and 41B become Low. Therefore, the state detection signal FB indicating the electric potential state of the electric path between the source of the positive side opening / closing switch 21A and the positive terminal of the brake device 2 is generated. A and a state detection signal FB indicating the potential state of the electric path between the drain of the negative side open / close switch 21B and the negative terminal of the brake device 2. B Both will be Low.

[0108] In this way, if the power supply 11 is normal, the status detection signal FB Aand F.B. B are both high, but if there is an abnormality in the power supply 11, the status detection signal FB A and F.B. B Therefore, during the second power supply inspection processing period, the abnormality detection unit 15 detects that the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. B Based on a combination of the contents of the state detection signal FB and the contents of the power supply control signal CTRP, the abnormality detection unit 15 detects whether an abnormality has occurred in the power supply 11. In the example shown in FIG. 15, during the second power supply inspection process, the abnormality detection unit 15 detects whether an abnormality has occurred in the power supply 11 based on the combination of the contents of the state detection signal FB A and F.B. B If both are High, it is determined that there is no abnormality in the power supply 11, and the status detection signal FB A and F.B. B If both of these are Low, it is determined that an abnormality has occurred in the power supply 11. When the abnormality detection unit 15 detects an abnormality in the power supply 11, it outputs an alarm signal. The alarm signal output from the abnormality detection unit 15 is sent to, for example, a display unit (not shown), and the display unit displays, for example, a message to notify an operator of an "abnormality in the power supply". Examples of the display unit include a standalone display device, a display device attached to a higher-level control device (not shown), a display device attached to the motor drive device 100, and a display device attached to a personal computer and a mobile terminal. In addition, for example, the alarm signal output from the abnormality detection unit 15 is sent to a light-emitting device (not shown), such as an LED or a lamp, and the light-emitting device emits light when receiving the alarm signal to notify an operator of an "abnormality". In addition, for example, the alarm signal output from the abnormality detection unit 15 is sent to, for example, an audio device (not shown), and the audio device emits a sound, such as a voice, a speaker, a buzzer, or a chime, when receiving the alarm signal to notify an operator of an "abnormality in the power supply". This allows the worker to easily and reliably recognize the occurrence of an abnormality in the power supply. The worker can easily take action, such as replacing the power supply. The alarm signal output from the abnormality detection unit 15 may be used for emergency shutdown processing of the motor drive device 100.

[0109] FIG. 16 is a flowchart showing an operation flow when applying the brake by the brake device that has been released for the motor in the brake control device according to the second embodiment of the present disclosure.

[0110] During the execution of the brake release process, the second power supply inspection process, and the brake activation process, the state detection unit 14 outputs a state detection signal FB A , and a state detection signal FB indicating the potential state of the electric path between the drain of the negative side switch 21B in the switching unit 13 and the negative terminal of the brake device 2. B Output.

[0111] In step S201, a brake release process is executed. In the brake release process, the brake control unit 12 outputs a brake control signal BS that controls the positive side opening / closing switch 21A and the negative side opening / closing switch 21B to close. A and B.S. B In addition, the power supply control unit 16 outputs an output on signal to the power supply 11.

[0112] In step S202, the brake control unit 12 judges whether or not a brake actuation command has been received from a higher-level control device (not shown). If it is judged in step S202 that a brake actuation command has not been received, the process returns to step S201 and continues to execute the brake release process. If it is judged in step S202 that a brake release command has been received, the process proceeds to step S203.

[0113] In step S203, a second power supply inspection process is executed. In the second power supply inspection process, the power supply control unit 16 outputs an output-off signal as a power supply control signal CTRP to the power supply 11, and the brake control unit 12 outputs a brake control signal BS A and B.S. BDuring the second power supply inspection process, the abnormality detection unit 15 outputs the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. B Based on a combination of the contents of this signal and the contents of the power supply control signal CTRP, the presence or absence of an abnormality in the power supply 11 is detected.

[0114] If an abnormality in the power supply 11 is detected in step S203, the process proceeds to step S204, and if an abnormality in the power supply 11 is not detected in step S203, the process proceeds to step S205.

[0115] In step S204, the abnormality detection unit 15 outputs an alarm signal to notify the operator of the occurrence of an abnormality in the power supply 11. After execution of step S204, the process proceeds to step S205 to apply the brakes to ensure safety.

[0116] In step S205, a brake actuation process is executed. In the brake actuation process, the brake control unit 12 outputs a brake control signal BS for controlling the positive side opening / closing switch 21A and the negative side opening / closing switch 21B to open. A and B.S. B Output.

[0117] As described above, according to the brake control device 1 according to the second embodiment of the present disclosure, it is possible to detect the occurrence of an abnormality in the power supply 11. Moreover, the brake by the brake device 2 acting on the motor 3 can be released only when no abnormality occurs. Moreover, even if an abnormality occurs when releasing the brake by the brake device 2 acting on the motor 3, it is possible to avoid a situation in which the brake is released. The first power supply inspection process and the second power supply inspection process may be executed in combination, or only one of them may be executed alone. That is, any of the following may be performed: "the first power supply inspection process is executed when transitioning from the brake activation process to the brake release preparation process, and the second power supply inspection process is executed when transitioning from the brake release process to the brake activation process", "only the first power supply inspection process is executed when transitioning from the brake activation process to the brake release preparation process", and "only the second power supply inspection process is executed when transitioning from the brake release process to the brake activation process".

[0118] Next, a third embodiment of the present disclosure will be described. In the third embodiment, an opening / closing switch constituting an opening / closing unit is provided in either an electric path between a positive terminal of a power source and a positive terminal of a brake device, or an electric path between a negative terminal of a power source and a negative terminal of a brake device.

[0119] Fig. 17 is a diagram showing a brake control device and a motor drive device including the same according to third and fourth embodiments of the present disclosure. Fig. 17 is also applicable to the fourth embodiment described later.

[0120] In the third embodiment, the opening / closing unit 13 has at least one opening / closing switch that opens / closes either one of the electric paths between the positive terminal of the power source 11 and the positive terminal of the brake device 2 or the electric path between the negative terminal of the power source 11 and the negative terminal of the brake device 2. In the example shown in FIG. 17, as an example, the opening / closing unit 13 has one opening / closing switch 22 that opens / closes the electric path between the negative terminal of the power source 11 and the negative terminal of the brake device 2. In the example shown in FIG. 17, one opening / closing switch is provided on one of the electric paths, but two or more opening / closing switches may be provided on one of the electric paths. For example, two opening / closing switches connected in series may be provided on the electric path between the negative terminal of the power source 11 and the negative terminal of the brake device 2, and in this case, these two opening / closing switches are controlled to open / close by the same brake control signal BS.

[0121] Also, as an example, the open / close switch 22 is a normally open switch. Examples of the semiconductor switching element constituting the open / close switch 22 include FET, IGBT, thyristor, GTO, transistor, etc., but other semiconductor switching elements may also be used. Below, a case where the open / close switch 22 is constituted by a FET will be described. When the open / close switch 22 is constituted by a thyristor and a GTO, the "gate" is replaced with the "base", the "drain" is replaced with the "anode", and the "source" is replaced with the "cathode" in this embodiment. When the open / close switch 22 is constituted by a transistor, the "gate" is replaced with the "base", the "drain" is replaced with the "collector", and the "source" is replaced with the "emitter" in this embodiment.

[0122] The brake control unit 12 outputs a brake control signal BS for opening and closing the open / close switch 22 in the opening / closing unit 13. The brake control signal BS output from the brake control unit 12 is sent to the open / close switch 22 and the abnormality detection unit 15. In the third embodiment of the present disclosure, the control processing content executed by the brake control unit 12 is divided into two processes, a brake activation process and a brake release process, and a brake control signal BS corresponding to each process is sent to the open / close switch 22. The brake activation process and the brake release process in the brake control device 1 will be described in detail later.

[0123] The state detection unit 14 also includes, for example, a photocoupler 41C, voltage-dividing resistors R1C and R2C, and a pull-up resistor R3C in order to generate a state detection signal FB indicating the potential state of the electric path between the drain of the open / close switch 22 in the open / close unit 13 and the negative terminal of the brake device 2. One end of the voltage-dividing resistor R1C is connected to the electric path connecting the negative terminal of the brake device 2 and the drain of the open / close switch 22, and the other end of the voltage-dividing resistor R1C is connected to one end of the voltage-dividing resistor R2C. The other end of the voltage-dividing resistor R2C is grounded. The light-emitting element in the photocoupler 41C is connected in parallel to the voltage-dividing resistor R2C. One end of the light-receiving element in the photocoupler 41C is connected to the pull-up resistor R3C, and the other end of the light-receiving element in the photocoupler 41C is grounded. In the example shown in FIG. 17, the state detection unit 14 is configured with a photocoupler and various resistors, but it may also be configured with a power supply that outputs a reference voltage for distinguishing between a High state and a Low state (instead of a power supply, the reference voltage may be generated by a method such as resistor division), and a comparator that compares the reference voltage with the voltage applied to the voltage dividing resistor R2C and outputs a High signal or a Low signal based on the result of the comparison.

[0124] The abnormality detection unit 15 detects whether an abnormality has occurred based on a combination of the contents of the brake control signal BS and the contents of the state detection signal FB. Details of the abnormality detection process by the abnormality detection unit 15 will be described later. The abnormality detection unit 15 also has a function of outputting an alarm signal when it detects the occurrence of an abnormality.

[0125] The abnormalities detected by the abnormality detection unit 15 include a short circuit failure of the open / close switch 22, a short circuit between a cable constituting between the open / close switch 22 and the brake device 2 and an external circuit, and a failure of the state detection unit 14. For example, when the open / close switch 22 does not respond to an open command received due to a failure of the drive circuit of the open / close switch 22 and the open / close switch 22 remains in a closed state, the failure can be regarded as a "short circuit failure of the open / close switch 22."

[0126] The details of the power source 11, the power source control unit 16, the brake device 2, and the motor 3 are as described in the first embodiment.

[0127] Next, the brake control process and the state detection process in the brake control device 1 according to the third embodiment of the present disclosure will be described.

[0128] Fig. 18A is a diagram for explaining each signal and brake state in a normal state in the brake control device 1 according to the third embodiment of the present disclosure, and shows a table showing each signal and brake state. Fig. 18B is a diagram for explaining each signal and brake state in a normal state in the brake control device 1 according to the third embodiment of the present disclosure, and shows a timing chart showing each signal and brake state. Note that the "brake control signal" is written as "brake signal" in Figs. 18A and 18B to simplify the drawings.

[0129] In the third embodiment of the present disclosure, the control process executed in the brake control device 1 is divided into two processes, a brake activation process and a brake release process. A state in which the brake device 2 applies a brake to the motor 3 is realized by executing the brake activation process. A state in which the brake device 2 applies a brake to the motor 3 is released by executing the brake release process. When releasing the brake applied to the motor 3, the brake activation process is terminated and the brake release process is executed. When applying the brake to the motor 3 from a state in which the brake is released, the brake release process is terminated and the brake activation process is executed. In the following description, as an example, the open / close switch 22 is a normally open switch.

[0130] In the brake actuation process, the brake control unit 12 outputs a brake control signal BS for controlling the opening / closing switch 22 to be opened. Since the opening / closing switch 22 is a normally open switch, the brake control unit 12 outputs a Low signal as the brake control signal BS to the opening / closing switch 22. If there is no abnormality in the opening / closing switch 22 and the devices related thereto, the abnormality detection unit 15 does not detect the occurrence of an abnormality, so the power supply control unit 16 outputs an output-on signal to the power supply 11, and therefore, a DC voltage (a DC voltage of 24 V in the example shown in FIG. 17) is output from the power supply 11. Since the opening / closing switch 22 is opened by the brake actuation process, the electric path from the positive terminal of the power supply 11 through the brake device 2 to the negative terminal of the power supply 11 is interrupted. Therefore, if there is no abnormality in the opening / closing switch 22 and the devices related thereto, the brake control unit 12 executes the brake actuation process, so that the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked. Furthermore, since the open / close switch 22 is open, the current flowing out from the positive terminal of the power source 11 flows through the brake device 2 and the voltage dividing resistors R1C and R2C. Therefore, the light emitting element in the photocoupler 41C emits light, and the output side of the photocoupler 41C becomes Low. Therefore, the state detection signal FB, which indicates the potential state of the electric path between the drain of the open / close switch 22 in the opening / closing unit 13 and the negative terminal of the brake device 2, becomes Low.

[0131] In the brake release process, the brake control unit 12 outputs a brake control signal BS for controlling the opening / closing switch 22 to be closed. Since the opening / closing switch 22 is a normally open switch, the brake control unit 12 outputs a High signal as the brake control signal BS to the opening / closing switch 22. If there is no abnormality in the opening / closing switch 22 and the devices related thereto, the abnormality detection unit 15 does not detect the occurrence of an abnormality, so the power supply control unit 16 outputs an output-on signal to the power supply 11, and therefore, a DC voltage (a DC voltage of 24 V in the example shown in FIG. 1) is output from the power supply 11. Since the opening / closing switch 22 is closed by the brake release process, an electric path is formed from the positive terminal of the power supply 11 through the brake device 2 to the negative terminal of the power supply 11. Therefore, if there is no abnormality in the opening / closing switch 22 and the devices related thereto, the voltage of the power supply 11 is applied to the brake coil 115 of the brake device 2 by executing the brake release process. Thus, the brake for the motor 3 is released. Furthermore, the electric path from the negative terminal of the braking device 2, via the open / close switch 22, to the negative terminal of the power source 11 has the same potential as 0V, which is the potential of the negative terminal of the power source 11. As a result, no current flows through the voltage dividing resistors R1C and R2C in the state detection unit 14, so the light emitting element in the photocoupler 41C does not emit light, and therefore the output side of the photocoupler 41C is High. As a result, the state detection signal FB, which indicates the potential state of the electric path between the drain of the open / close switch 22 in the opening / closing unit 13 and the negative terminal of the braking device 2, is High.

[0132] The contents of the state detection signal FB in the brake activation process and brake release process when there is no abnormality in the above-mentioned opening / closing switch 22 and related devices, i.e., in normal operating conditions, are stored in advance in the abnormality detection unit 15 so as to be available for the abnormality detection process.

[0133] Fig. 19A is a diagram for explaining each signal and brake state when a short circuit occurs in an open / close switch in a brake control device when a constant voltage is output without output control of the power supply, and shows a table showing each signal and brake state. Fig. 19B is a diagram for explaining each signal and brake state when a short circuit occurs in an open / close switch in a brake control device when a constant voltage is output without output control of the power supply, and shows a timing chart showing each signal and brake state. Note that the "brake control signal" is written as "brake signal" in Figs. 19A and 19B to simplify the drawings.

[0134] 19A and 19B show signals and brake states when the open / close switch 22 has a short-circuit failure, assuming that the power source 11 is not an output controllable power source (i.e., a power source having a variable output) but is a power source that outputs a voltage of a constant magnitude (e.g., 24 V). When the open / close switch 22 has a short-circuit failure, the open / close switch 22 is closed because the open / close switch 22 has a short-circuit failure, even though a low signal, which is an open command, is output as a brake control signal BS to the open / close switch 22 during the brake activation process. Therefore, an electric path is formed from the positive terminal of the power source 11 through the brake device 2 and the open / close switch 22 to the negative terminal of the power source 11. As a result, the voltage of the power source 11 is applied to the brake device 2, and the brake on the motor 3 is released. In this way, if a short-circuit failure occurs in the open / close switch 22 during the execution of the brake release preparation process, the brake is released when it should be activated, which is dangerous. The electric path from the negative terminal of the brake device 2 to the drain of the open / close switch 22 has the same potential as 0 V, which is the potential of the negative terminal of the power source 11. As a result, no current flows through the voltage dividing resistors R1C and R2C in the status detection unit 14, so the light emitting element in the photocoupler 41C does not emit light, and therefore the output side of the photocoupler 41C becomes High. Therefore, the status detection signal FB, which indicates the potential state of the electric path between the drain of the open / close switch 22 in the opening / closing unit 13 and the negative terminal of the brake device 2, becomes High. In this way, during the brake activation process, if there is no abnormality in the open / close switch 22 and its related devices, the status detection signal FB is Low, but if the open / close switch 22 suffers a short circuit failure, the status detection signal FB becomes High. The abnormality detection unit 15 detects the presence or absence of an abnormality based on the combination of the contents of the brake control signal BS and the contents of the status detection signal FB during execution of the brake activation process.More specifically, when transitioning from brake activation processing to brake release processing, if the brake control signal BS is low and the state detection signal FB is low during execution of the brake activation processing immediately before the brake release processing, the abnormality detection unit 15 determines that no abnormality has occurred, and the brake control unit 12 ends the brake activation processing and executes the brake release processing. When transitioning from brake activation processing to brake release processing, if the brake control signal BS is low and the state detection signal FB is high during execution of the brake activation processing immediately before the brake release processing, the abnormality detection unit 15 determines that an abnormality has occurred (i.e., a short circuit failure of the open / close switch 22).

[0135] Fig. 20A is a diagram for explaining each signal and brake state when a short circuit occurs in an open / close switch in a brake control device having an output controllable power supply according to a third embodiment of the present disclosure, and shows a table showing each signal and brake state. Fig. 20B is a diagram for explaining each signal and brake state when a short circuit occurs in an open / close switch in a brake control device having an output controllable power supply according to a third embodiment of the present disclosure, and shows a timing chart showing each signal and brake state. Note that the "brake control signal" is written as "brake signal" in Figs. 20A and 20B to simplify the drawings.

[0136] As described with reference to FIG. 19A and FIG. 19B, when the brake control signal BS is Low and the state detection signal FB is High during the execution of the brake activation process, the abnormality detection unit 15 determines that an abnormality has occurred (i.e., a short circuit failure of the open / close switch 22). If a short circuit failure of the open / close switch 22 occurs during the brake activation process, the brake is released when it should have been activated, and the abnormality detection unit 15 outputs an alarm signal. As shown in FIG. 20A, when the brake activation process is shifted to the brake release process, if the abnormality detection unit 15 detects an abnormality during the execution of the brake activation process immediately before the brake release process, the power supply control unit 16 outputs an output off signal as a power supply control signal CTRP for the output controllable power supply 11, which controls the power supply 11 not to output a voltage. As a result, the power supply 11 does not output a DC voltage, that is, the DC output voltage of the power supply 11 is 0V, that is, the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked. This makes it possible to prevent the brake from being released when an abnormality occurs (when the open / close switch 22 has a short circuit).

[0137] As described above, according to the brake control device 1 according to the third embodiment of the present disclosure, only when no abnormality occurs, it is possible to release the brake applied by the brake device 2 applied to the motor 3. Furthermore, even if an abnormality occurs when releasing the brake applied by the brake device 2 applied to the motor 3, it is possible to avoid a situation in which the brake is released.

[0138] Next, a fourth embodiment of the present disclosure will be described. The power supply 11 in the third embodiment is a power supply whose output can be controlled based on a power supply control signal CTRP from the power supply control unit 16, and therefore has a higher probability of failure than a power supply that always outputs a constant voltage. The fourth embodiment of the present disclosure makes it possible to detect the occurrence of an abnormality in the power supply 11. The occurrence of an abnormality in the power supply can be detected by a power supply inspection process executed between a brake activation process and a brake release process.

[0139] FIG. 21A is a diagram illustrating each signal and brake state in a brake control device having a power supply inspection function according to a fourth embodiment of the present disclosure, illustrating each signal and brake state when the power supply is normal. FIG. 21B is a diagram illustrating each signal and brake state in a brake control device having a power supply inspection function according to a fourth embodiment of the present disclosure, illustrating each signal and brake state when the power supply is abnormal. For the sake of simplicity, in FIG. 21A and FIG. 21B, it is assumed that there is no occurrence of an abnormality such as a short circuit failure of the open / close switch 22 that may be detected during the execution of the brake activation process and the brake release process. In addition, the "brake control signal" is written as "brake signal" in FIG. 21A and FIG. 21B for the sake of simplicity.

[0140] The power supply inspection process is executed before executing the brake activation process when transitioning from the brake activation process to the brake release process. During the power supply inspection process, the power supply control unit 16 outputs an output off signal as the power supply control signal CTRP to the power supply 11, and the brake control unit 12 outputs a brake control signal BS that controls the open / close switch 22 to be open, as in the brake activation process. Since the open / close switch 22 is a normally open switch, the brake control unit 12 outputs a low signal as the brake control signal BS to the open / close switch 22.

[0141] As shown in Fig. 21A, if the power supply 11 is normal, during the power supply inspection process, the power supply 11 does not output a DC voltage in response to an output-off signal received from the power supply control unit 16, that is, the DC output voltage of the power supply 11 is 0V. Therefore, the electric potential of the electric path from the positive terminal of the power supply 11 through the brake device 2 and the open / close switch 22 to the negative terminal of the power supply 11 is the same as the electric potential of the positive and negative terminals of the power supply 11, which is 0V. Therefore, no current flows through the voltage dividing resistors R1C and R2C in the state detection unit 14, so that the light emitting element in the photocoupler 41C does not emit light, and therefore the output side of the photocoupler 41B is High. Therefore, the state detection signal FB, which indicates the electric potential state of the electric path between the drain of the open / close switch 22 in the open / close unit 13 and the negative terminal of the brake device 2, is High.

[0142] The contents of the state detection signal FB in the first power supply inspection process when the power supply 11 is normal as described above are stored in advance in the abnormality detection unit 15 so as to be available for the abnormality detection process for the power supply 11.

[0143] When a fault occurs in the power supply 11, such as "continuing to output voltage without responding to an output-off signal," as shown in FIG. 21B, the power supply 11 continues to output a DC voltage (for example, 24 V) even if it receives an output-off signal from the power supply control unit 16. Therefore, the electric path from the positive terminal of the power supply 11 to the positive terminal of the brake device 2 has the same potential as the voltage output by the positive terminal of the power supply 11 (24 V in the example shown in FIG. 1). In addition, since the electric path from the negative terminal of the brake device 2 to the negative terminal of the power supply 11 is cut off by the open-close switch 22, the current flowing out from the positive terminal of the power supply 11 flows through the brake device 2 and the voltage dividing resistors R1C and R2C. Therefore, the light-emitting element in the photocoupler 41C emits light, and therefore the output side of the photocoupler 41C becomes Low. Therefore, the state detection signal FB, which indicates the electric potential state of the electric path between the drain of the open-close switch 22 in the opening / closing unit 13 and the negative terminal of the brake device 2, becomes Low.

[0144] In this way, if the power supply 11 is normal, the status detection signal FB is High during the power supply inspection processing period, but if there is an abnormality in the power supply 11, the status detection signal FB is Low during the power supply inspection processing period. Therefore, the abnormality detection unit 15 detects whether or not an abnormality has occurred in the power supply 11 based on a combination of the contents of the brake control signal BS, the contents of the status detection signal FB, and the contents of the power supply control signal CTRP during the power supply inspection processing period. In the example shown in FIG. 17, the abnormality detection unit 15 determines that no abnormality has occurred in the power supply 11 if the status detection signal FB is High during the power supply inspection processing period, and determines that an abnormality has occurred in the power supply 11 if the status detection signal FB is Low. If the abnormality detection unit 15 detects an abnormality in the power supply 11, it outputs an alarm signal. The alarm signal output from the abnormality detection unit 15 is sent to, for example, a display unit (not shown), and the display unit displays, for example, a message notifying an operator that "an abnormality has occurred in the power supply." Examples of the display unit include a standalone display device, a display device attached to the motor drive device 100, a display device attached to a higher-level control device (not shown), and a display device attached to a personal computer and a mobile terminal. For example, the alarm signal output from the abnormality detection unit 15 is sent to a light-emitting device (not shown) such as an LED or a lamp, and the light-emitting device emits light when receiving the alarm signal to notify the operator of the occurrence of an abnormality in the power supply. For example, the alarm signal output from the abnormality detection unit 15 is sent to an audio device (not shown), and the audio device emits a sound such as a voice, a speaker, a buzzer, or a chime when receiving the alarm signal to notify the operator of the occurrence of an abnormality in the power supply. This allows the operator to reliably and easily grasp the occurrence of an abnormality in the power supply. It also becomes easy for the operator to take measures such as replacing the power supply. The alarm signal output from the abnormality detection unit 15 may be used for emergency stop processing of the motor drive device 100.

[0145] FIG. 22 is a flowchart showing an operation flow when releasing the brake applied by the brake device to the motor in the brake control device according to the fourth embodiment of the present disclosure.

[0146] During the execution of the brake activation process, power supply inspection process, and brake release process, the status detection unit 14 outputs a status detection signal FB indicating the potential state of the electrical path between the drain of the opening / closing switch 22 in the opening / closing unit 13 and the negative terminal of the brake device 2.

[0147] In step S301, a brake actuation process is executed. In the brake actuation process, the brake control unit 12 outputs a brake control signal BS for controlling the opening / closing switch 22 to open. In addition, the power supply control unit 16 outputs an output on signal to the power supply 11.

[0148] In step S302, the brake control unit 12 judges whether or not a brake release command has been received from a higher-level control device (not shown). If it is judged in step S302 that the brake release command has not been received, the process returns to step S301 and continues executing the brake activation process. If it is judged in step S302 that the brake release command has been received, the process proceeds to step S303.

[0149] In step S303, a power supply inspection process is executed. In the power supply inspection process, the power supply control unit 16 outputs an output-off signal as the power supply control signal CTRP to the power supply 11, and the brake control unit 12 outputs a brake control signal BS that controls the open / close switch 22 to be open. During the power supply inspection process, the abnormality detection unit 15 detects whether or not an abnormality has occurred in the power supply 11 based on a combination of the contents of the brake control signal BS, the contents of the state detection signal FB, and the contents of the power supply control signal CTRP.

[0150] If an abnormality in the power supply 11 is detected in step S303, the process proceeds to step S304. In step S304, the abnormality detection unit 15 outputs an alarm signal to notify the operator of the abnormality in the power supply 11. Then, the process ends. That is, in this case, the brake control unit 12 continues to execute the brake activation process and does not execute the brake release process.

[0151] If no abnormality in the power supply 11 is detected in step S303, the process proceeds to step S305. In step S305, a brake release process is executed. In the brake release process, the brake control unit 12 outputs a brake control signal BS that controls the open / close switch 22 to close. The brake release process in step S305 is executed in this manner only when no abnormality is detected in step S302 during execution of the brake activation process, and therefore the brake can be released safely.

[0152] Next, a fifth embodiment of the present disclosure will be described. The fifth embodiment of the present disclosure is the second embodiment further including a brake lock switch that shorts the input terminals of the brake device 2 when an abnormality occurs, and a brake lock switch control unit including the brake lock switch.

[0153] FIG. 23 is a diagram illustrating a brake control device and a motor drive device including the brake control device according to the fifth embodiment of the present disclosure.

[0154] The brake control device 1 according to the fifth embodiment further includes a brake lock switch 17 and a brake lock switch control unit 18 in addition to the components of the brake control device 1 according to the second embodiment shown in FIG.

[0155] The brake lock switch 17 is connected between the input terminals of the brake device 2 (i.e., between the positive and negative terminals of the brake device 2) so as to be connected in parallel to the brake device 2, and opens and closes an electric path in response to a brake lock control signal received from a brake lock switch control unit 18. The brake lock switch 17 may be configured with a semiconductor switching element, or may be configured with a mechanical switch such as a relay. Examples of the semiconductor switching element constituting the brake lock switch 17 include FET, IGBT, thyristor, GTO, transistor, etc., but other semiconductor switching elements may also be used. In the example shown in FIG. 23, as an example, the brake lock switch 17 is a normally-off relay.

[0156] The brake lock switch control unit 18 outputs a close signal as a brake lock control signal to the brake lock switch 17 to control the brake lock switch 17 to close when an abnormality is detected by the abnormality detection unit 15, and outputs an open signal to control the brake lock switch 17 to open when no abnormality is detected by the abnormality detection unit 15.

[0157] The brake lock switch control unit 18 is provided in an arithmetic processing device (processor) provided in the brake control device 1. The brake lock switch control unit 18 of the arithmetic processing device is, for example, a functional module realized by a computer program executed on the processor. For example, when the brake lock switch control unit 18 is constructed in the form of a computer program, the function of the brake lock switch control unit 18 can be realized by operating the arithmetic processing device according to the computer program. The computer program for executing the processing of the brake lock switch control unit 18 may be provided in a form recorded on a computer-readable recording medium such as a semiconductor memory, a magnetic recording medium, or an optical recording medium. Alternatively, the brake lock switch control unit 18 may be realized as a semiconductor integrated circuit in which a computer program for realizing the function is written.

[0158] 24A to 27 are diagrams illustrating examples of signals and brake states in a brake control device according to a fifth embodiment of the present disclosure. In Fig. 24A to 27, in order to simplify the drawings, the "brake control signal" is expressed as the "brake signal" and the "power-on control process". In the following description, as an example, the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are normally open switches.

[0159] FIG. 24A is a diagram illustrating each signal and brake state in the brake control device according to the fifth embodiment of the present disclosure, illustrating each signal and brake state in normal operation. FIG. 24B is a diagram illustrating each signal and brake state in the brake control device according to the fifth embodiment of the present disclosure, illustrating each signal and brake state in the event of a power supply abnormality. FIG. 25A is a diagram illustrating each signal and brake state in the brake control device according to the fifth embodiment of the present disclosure, illustrating each signal and brake state in the event of a short circuit failure of the negative side opening / closing switch. FIG. 25B is a diagram illustrating each signal and brake state in the brake control device according to the fifth embodiment of the present disclosure, illustrating each signal and brake state in the event of a short circuit failure of the positive side opening / closing switch. FIG. 26A is a diagram illustrating each signal and brake state in the brake control device according to the fifth embodiment of the present disclosure, illustrating each signal and brake state when the first protection operation process is performed in the event of a short circuit failure of the positive side opening / closing switch and the negative side opening / closing switch. Fig. 26B is a diagram illustrating each signal and brake state in the brake control device according to the fifth embodiment of the present disclosure, and illustrates each signal and brake state when the second protective operation process is performed when the positive side opening / closing switch and the negative side opening / closing switch have a short circuit. Fig. 27 is a diagram illustrating each signal and brake state in the brake control device according to the fifth embodiment of the present disclosure, and illustrates each signal and brake state when the third protective operation process is performed when the positive side opening / closing switch and the negative side opening / closing switch have a short circuit.

[0160] The control process contents in the brake control device 1 in the fifth embodiment of the present disclosure are divided into five processes, namely, a brake activation process, a first brake release preparation process, a power-on control process, a second brake release preparation process, and a brake release process, and a brake control signal, a power control signal, and a brake lock control signal are generated according to each process. The state detection unit 14 generates a state detection signal FB indicating the potential state of the electric path between the source of the positive side opening / closing switch 21A in the opening / closing unit 13 and the positive terminal of the brake device 2 during the execution of each of the brake activation process, the first brake release preparation process, the power-on control process, the second brake release preparation process, and the brake release process. A, and a state detection signal FB indicating the potential state of the electric path between the drain of the negative side switch 21B in the switching unit 13 and the negative terminal of the brake device 2. B Generate.

[0161] First, a case where there is no abnormality in any of the devices in the brake control device 1 according to the fifth embodiment of the present disclosure will be described with reference to FIG. 24A.

[0162] In the brake activation process, the power supply control unit 16 outputs an output off signal, and the brake control unit 12 controls the positive side opening / closing switch 21A and the negative side opening / closing switch 21B to open a brake control signal BS A and B.S. B The brake lock switch control unit 18 outputs a brake lock control signal to open the brake lock switch 17. Since the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are normally open switches, the brake control unit 12 outputs a brake control signal BS A and outputs a low signal as a brake control signal BS B The power supply 11 that has received the output-off signal does not output a DC voltage, that is, the DC output voltage of the power supply 11 is 0V. In addition, since the positive side open / close switch 21A and the negative side open / close switch 21B are opened by the brake activation process, the electric path from the positive terminal of the power supply 11 to the negative terminal of the power supply 11 via the brake device 2 is cut off. Therefore, when there is no abnormality in each device in the brake control device 1, the brake control unit 12 executes the brake activation process, and the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is in a brake-activated state. In addition, since no current flows through the voltage dividing resistors R1A and R2A and the voltage dividing resistors R1B and R2B in the state detection unit 14, the light-emitting elements in the photocouplers 41A and 41B do not emit light, and therefore the output sides of the photocouplers 41A and 41B are High. Therefore, the state detection signal FB indicating the electric potential state of the electric path between the source of the positive side open / close switch 21A and the positive terminal of the brake device 2 is Aand a state detection signal FB indicating the potential state of the electric path between the drain of the negative side open / close switch 21B and the negative terminal of the brake device 2. B Both will be High.

[0163] The first brake release preparation process is executed after the brake application process when the brake application process is shifted to the brake release process. During the first brake release preparation process, the power supply control unit 16 outputs an output off signal as a power supply control signal CTRP to the power supply 11, and the brake control unit 12 controls the positive side opening / closing switch 21A to be closed and the negative side opening / closing switch 21B to be opened by the brake control signal BS A and B.S. B The brake lock switch control unit 18 outputs a brake lock control signal to open the brake lock switch 17. Since the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are normally open switches, the brake control unit 12 outputs a brake control signal BS A and outputs a high signal as a brake control signal BS B The power supply 11 that has received the output-off signal does not output a DC voltage, that is, the DC output voltage of the power supply 11 is 0V. In addition, since the negative side open / close switch 21B is open, the electric path from the positive terminal of the power supply 11 through the brake device 2 to the negative terminal of the power supply 11 is cut off. Therefore, if there is no abnormality in each device in the brake control device 1, the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2 by executing the first brake activation process. Therefore, the motor 3 is in a brake activated state. In addition, since no current flows through the voltage dividing resistors R1A and R2A and the voltage dividing resistors R1B and R2B in the state detection unit 14, the light emitting elements in the photocouplers 41A and 41B do not emit light, and therefore the output sides of the photocouplers 41A and 41B are High. Therefore, the state detection signal FB indicating the electric potential state of the electric path between the source of the positive side open / close switch 21A and the positive terminal of the brake device 2 is Aand a state detection signal FB indicating the potential state of the electric path between the drain of the negative side open / close switch 21B and the negative terminal of the brake device 2. B In this way, when there is no abnormality in the devices in the brake control device 1, the state detection signal FB A and F.B. B is the status detection signal FB during the brake operation processing period. A and F.B. B It becomes the same as:

[0164] The power-on control process is executed after the first brake release preparation process when transitioning from the brake activation process to the brake release process. During the power-on control process, the power supply control unit 16 outputs an output-on signal as the power supply control signal CTRP to the power supply 11, and the brake control unit 12 outputs a brake control signal BS A and B.S. B The brake lock switch control unit 18 outputs a brake lock control signal to open the brake lock switch 17. Since the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are normally open switches, the brake control unit 12 outputs a brake control signal BS A and outputs a high signal as a brake control signal BS B23 )。 The power supply 11 that has received the output-on signal outputs a DC voltage (a DC voltage of 24 V in the example shown in FIG. 23 ). Since the positive side opening / closing switch 21A is closed but the negative side opening / closing switch 21B is open, the electric path from the positive terminal of the power supply 11 through the brake device 2 to the negative terminal of the power supply 11 is cut off. Therefore, if there is no abnormality in each device in the brake control device 1, the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Thus, the motor 3 is braked. In addition, the electric path from the positive terminal of the power supply 11 through the positive side opening / closing switch 21A and the brake device 2 to the drain of the negative side opening / closing switch 21B has the same potential as the voltage output by the positive terminal of the power supply 11 (24 V in the example shown in FIG. 23 ). Therefore, current flows through the voltage dividing resistors R1A and R2A and the voltage dividing resistors R1B and R2B in the state detection unit 14, so that the light emitting elements in the photocouplers 41A and 41B emit light, and the output sides of the photocouplers 41A and 41B become Low. A and a state detection signal FB indicating the potential state of the electric path between the drain of the negative side open / close switch 21B and the negative terminal of the brake device 2. B Both will be Low.

[0165] The second brake release preparation process is executed after the power-on control when transitioning from the brake activation process to the brake release process. During the second brake release preparation process, the power supply control unit 16 outputs an output-on signal as a power supply control signal CTRP to the power supply 11, and the brake control unit 12 outputs a brake control signal BS A and B.S. B The brake lock switch control unit 18 outputs a brake lock control signal to open the brake lock switch 17. Since the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are normally open switches, the brake control unit 12 outputs a brake control signal BS Aand outputs a low signal as a brake control signal BS B 23 , and outputs a Low signal. When the power source 11 receives the output-on signal, the power source 11 outputs a DC voltage (a DC voltage of 24 V in the example shown in FIG. 23 ). Since the positive side open / close switch 21A and the negative side open / close switch 21B are open, the electric path from the positive terminal of the power source 11 through the brake device 2 to the negative terminal of the power source 11 is cut off. Therefore, if there is no abnormality in each device in the brake control device 1, the voltage of the power source 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is in a brake-operated state. Also, since no current flows through the voltage dividing resistors R1A and R2A and the voltage dividing resistors R1B and R2B in the state detection unit 14, the light-emitting elements in the photocouplers 41A and 41B do not emit light, and therefore the output sides of the photocouplers 41A and 41B are High. Therefore, the state detection signal FB A and a state detection signal FB indicating the potential state of the electric path between the drain of the negative side open / close switch 21B and the negative terminal of the brake device 2. B Both will be High.

[0166] The brake release process is executed after the second brake release preparation process when transitioning from the brake activation process to the brake release process. During the brake release process, the power supply control unit 16 outputs an output on signal as the power supply control signal CTRP to the power supply 11, and the brake control unit 12 outputs a brake control signal BS A and B.S. B The brake lock switch control unit 18 outputs a brake lock control signal to open the brake lock switch 17. Since the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are normally open switches, the brake control unit 12 outputs a brake control signal BS A and outputs a high signal as a brake control signal BS B23 , and outputs a High signal. When there is no abnormality in each device in the brake control device 1, the power source 11 outputs a DC voltage (a DC voltage of 24 V in the example shown in FIG. 23 ). Since the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are closed by the brake release process, an electric path is formed from the positive terminal of the power source 11 through the brake device 2 to the negative terminal of the power source 11. Therefore, when there is no abnormality in the positive side opening / closing switch 21A, the negative side opening / closing switch 21B and the devices related thereto, the brake control unit 12 executes the brake release process, and the voltage of the power source 11 is applied to the brake coil 115 of the brake device 2. Therefore, the brake for the motor 3 is released. In addition, the electric path from the positive terminal of the power source 11 through the positive side opening / closing switch 21A to the positive terminal of the brake device 2 has the same potential as the voltage output by the positive terminal of the power source 11 (24 V in the example shown in FIG. 23 ). As a result, a current flows through the voltage dividing resistors R1A and R2A in the state detection unit 14, causing the light emitting element in the photocoupler 41A to emit light, and therefore the output side of the photocoupler 41A becomes low. Therefore, the state detection signal FB A becomes Low. Also, the electric potential of the electric path from the negative terminal of the brake device 2 through the negative side opening / closing switch 21B to the negative terminal of the power source 11 is the same as 0V, which is the electric potential of the negative terminal of the power source 11. Therefore, no current flows through the voltage dividing resistors R1B and R2B in the state detection unit 14, so that the light emitting element in the photocoupler 41B does not emit light, and therefore the output side of the photocoupler 41B becomes High. Therefore, the state detection signal FB B will be High.

[0167] When there is no abnormality in the positive side opening / closing switch 21A and the negative side opening / closing switch 21B and the devices related thereto and the power supply 11, that is, in a normal state, the state detection signal FB A and F.B. BThe contents of the above are stored in advance in the abnormality detection unit 15 so that they can be used in the abnormality detection process described later.

[0168] Next, a case where a failure occurs in the power supply 11 will be described with reference to FIG. 24B.

[0169] If a fault occurs in the power supply 11, such as "continuing to output voltage without responding to an output-off signal," the power supply 11 will continue to output a DC voltage (e.g., 24 V) even if it receives an output-off signal from the power supply control unit 16 during the brake activation processing period and the first brake release preparation processing period. If such a fault occurs in the power supply 11, the status detection signal FB A and F.B. B During the brake operation processing period, there is no change from normal, but during the first brake release preparation processing period, a signal state different from normal occurs. That is, during the first brake release preparation processing period, the positive side open / close switch 21A is closed and the negative side open / close switch 21B is open, so that the electric path from the positive terminal of the power source 11 to the drain of the negative side open / close switch 21B via the positive side open / close switch 21A and the brake device 2 has the same potential as the voltage output from the positive terminal of the power source 11 (24 V in the example shown in FIG. 1). Therefore, current flows through the voltage dividing resistors R1A and R2A and the voltage dividing resistors R1B and R2B in the state detection unit 14, so that the light emitting elements in the photocouplers 41A and 41B emit light, and therefore the output sides of the photocouplers 41A and 41B become Low. Therefore, the state detection signal FB indicating the electric potential state of the electric path between the source of the positive side open / close switch 21A and the positive terminal of the brake device 2 is A and a state detection signal FB indicating the potential state of the electric path between the drain of the negative side open / close switch 21B and the negative terminal of the brake device 2. B Both will be Low.

[0170] In this way, when a failure occurs in the power supply 11 such that "it does not respond to the output off signal and continues to output voltage," the state detection signal FB A and F.B. B is the status detection signal FB during the brake operation processing period.A and F.B. B During the first brake release preparation process, the abnormality detection unit 15 detects the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. B In more detail, the abnormality detection unit 15 detects whether or not an abnormality has occurred in the power supply 11 based on the combination of the state detection signal FB A and F.B. B is the status detection signal FB during the brake operation processing period A and F.B. B (state detection signal FB A and F.B. B and become Low), the abnormality detection unit 15 determines that a failure has occurred in the power supply 11 and outputs an alarm signal. A and F.B. B is the status detection signal FB during the brake operation processing period A and F.B. B (state detection signal FB A and F.B. B and both become High), it is determined that no fault has occurred in the power supply 11. Note that even if the abnormality detection unit 15 detects a fault in the power supply 11 during the first brake release preparation processing period, the electric path from the positive terminal of the power supply 11 to the negative terminal of the power supply 11 via the brake device 2 is still cut off by opening the negative side open / close switch 21B, so the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked, and safety is ensured.

[0171] Next, a case where a short circuit failure occurs in the negative side open-close switch 21B will be described with reference to FIG. 25A.

[0172] When a short circuit occurs in the negative side open / close switch 21B, the state detection signal FB B However, the signal state is different from that in the normal state. That is, during the power-on control processing period, the positive side opening / closing switch 21A is closed and the negative side opening / closing switch 21B is open under normal conditions, but if a short circuit failure occurs in the negative side opening / closing switch 21B, the negative side opening / closing switch 21B is in the same state as if it were closed. During the power-on control processing period, the power source 11 that receives the output-on signal outputs a DC voltage (a DC voltage of 24 V in the example shown in FIG. 1) from the power source 11. Due to a short circuit failure in the negative side opening / closing switch 21B, both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are in the closed state, so that an electric path is formed from the positive terminal of the power source 11 through the brake device 2 to the negative terminal of the power source 11. The electric path from the positive terminal of the power source 11 through the positive side opening / closing switch 21A to the positive terminal of the brake device 2 has the same potential as the voltage output by the positive terminal of the power source 11 (24 V in the example shown in FIG. 1). As a result, a current flows through the voltage dividing resistors R1A and R2A in the state detection unit 14, causing the light emitting element in the photocoupler 41A to emit light, and therefore the output side of the photocoupler 41A becomes low. A becomes Low. Also, the electric potential of the electric path from the negative terminal of the brake device 2 through the negative side opening / closing switch 21B to the negative terminal of the power source 11 is the same as 0V, which is the electric potential of the negative terminal of the power source 11. Therefore, no current flows through the voltage dividing resistors R1B and R2B in the state detection unit 14, so that the light emitting element in the photocoupler 41B does not emit light, and therefore the output side of the photocoupler 41B becomes High. Therefore, the state detection signal FB B will be High.

[0173] In this way, when a short circuit occurs in the negative side open / close switch 21B, the state detection signal FB BDuring the power-on control process, the abnormality detection unit 15 detects the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. B In more detail, the abnormality detection unit 15 detects whether or not a short circuit fault has occurred in the negative side open-close switch 21B based on a combination of the contents of the state detection signal FB A and F.B. B When both are Low, it is determined that there is no short circuit failure in the negative side open / close switch 21B, and the state detection signal FB A is Low and the status detection signal FB B is High, it is determined that an abnormality has occurred (that is, a short circuit failure of the negative side open / close switch 21B). When the abnormality detection unit 15 detects the occurrence of an abnormality during the execution of the power-on control process, it outputs an alarm signal.

[0174] Next, a case where a short circuit failure occurs in the positive side opening / closing switch 21A will be described with reference to FIG. 25B.

[0175] When a short circuit occurs in the positive side open / close switch 21A, the state detection signal FB A and F.B. BHowever, the signal state is different from that in the normal state. That is, during the second brake release preparation processing period, both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are open under normal conditions, but if a short circuit failure occurs in the positive side opening / closing switch 21A, the positive side opening / closing switch 21A is in the same state as if it were closed. During the second brake release preparation processing period, the power source 11 that receives the output on signal outputs a DC voltage (a DC voltage of 24 V in the example shown in FIG. 1) from the power source 11. Since the positive side opening / closing switch 21A is in the closed state due to the short circuit failure of the positive side opening / closing switch 21A, an electric path is formed from the positive terminal of the power source 11 to the drain of the negative side opening / closing switch 21B via the positive side opening / closing switch 21A and the brake device 2. The electric path from the positive terminal of the power source 11 to the drain of the negative side opening / closing switch 21B via the positive side opening / closing switch 21A and the brake device 2 has the same potential as the voltage output by the positive terminal of the power source 11 (24 V in the example shown in FIG. 1). As a result, current flows through the voltage dividing resistors R1A and R2A and the voltage dividing resistors R1B and R2B in the state detection unit 14, causing the light emitting elements in the photocouplers 41A and 41B to emit light, and therefore the output sides of the photocouplers 41A and 41B are both low. A and a state detection signal FB indicating the potential state of the electric path between the drain of the negative side open / close switch 21B and the negative terminal of the brake device 2. B Both will be Low.

[0176] In this way, when a short circuit occurs in the positive side opening / closing switch 21A, the state detection signal FB A and F.B. B During the second brake release preparation process, the abnormality detection unit 15 detects the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. BIn more detail, the abnormality detection unit 15 detects whether or not a short circuit fault has occurred in the positive side opening / closing switch 21A based on a combination of the contents of the state detection signal FB A and F.B. B When both are High, it is determined that there is no short circuit failure in the positive side opening / closing switch 21A, and the state detection signal FB A and F.B. B are both low, it is determined that an abnormality has occurred (i.e., a short-circuit failure of the positive side opening / closing switch 21A). If the abnormality detection unit 15 detects an abnormality during execution of the second brake release preparation process, it outputs an alarm signal. Note that since the electric path from the positive terminal of the power source 11 through the brake device 2 to the negative terminal of the power source 11 is cut off by opening the negative side opening / closing switch 21B, the voltage of the power source 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked, and safety is ensured.

[0177] Next, a case where the first protective operation process is performed when a short-circuit fault occurs in the positive side opening / closing switch 21A and the negative side opening / closing switch 21B will be described with reference to FIG. 26A.

[0178] When a short circuit occurs in both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B, the state detection signal FB A and F.B. BHowever, the signal state is different from that in the normal state. That is, in the normal state, the positive side opening / closing switch 21A is closed and the negative side opening / closing switch 21B is opened during the power-on control processing period, and both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are opened during the second brake release preparation processing period, but if a short circuit failure occurs in both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B, the negative side opening / closing switch 21B is in the same state as being closed. During the power-on control processing period, the power source 11 that has received the output-on signal outputs a DC voltage (a DC voltage of 24 V in the example shown in FIG. 23 ). Due to a short circuit failure in both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B, both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are in the closed state, so that an electric path is formed from the positive terminal of the power source 11 through the brake device 2 to the negative terminal of the power source 11. The electric path from the positive terminal of the power source 11, via the positive side switch 21A, to the positive terminal of the brake device 2 has the same potential as the voltage output by the positive terminal of the power source 11 (24 V in the example shown in FIG. 1). Therefore, a current flows through the voltage dividing resistors R1A and R2A in the state detection unit 14, causing the light emitting element in the photocoupler 41A to emit light, and therefore the output side of the photocoupler 41A becomes Low. Therefore, the state detection signal FB A becomes Low. The electric potential of the electric path from the negative terminal of the brake device 2 through the negative side opening / closing switch 21B to the negative terminal of the power source 11 is the same as 0V, which is the electric potential of the negative terminal of the power source 11. Therefore, no current flows through the voltage dividing resistors R1B and R2B in the state detection unit 14, so that the light emitting element in the photocoupler 41B does not emit light, and therefore the output side of the photocoupler 41B becomes High. Therefore, the state detection signal FB B will be High.

[0179] In this way, when a short circuit occurs in both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B, the state detection signal FB A and F.B. B During the power-on control process and the second brake release preparation process, the abnormality detection unit 15 detects the brake control signal BS A and B.S. B Contents and status detection signal FB A and F.B. B In more detail, the abnormality detection unit 15 detects whether or not a short circuit fault has occurred in the positive side open-close switch 21A based on a combination of the contents of the state detection signal FB A are both low and the status detection signal FB B If the signal is High, it is determined that an abnormality has occurred (that is, a short circuit failure has occurred in both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B), and an alarm signal is output.

[0180] If a short circuit failure occurs in the negative side opening / closing switch 21B during the power on control process period and during the second brake release preparation process period, the brake on the motor 3 may be released, resulting in a dangerous state. Therefore, the time period for executing the power on control process may be set to a time shorter than the response time of the brake device 2 to a brake command. Similarly, the time period for executing the second brake release preparation process may be set to a time shorter than the response time of the brake device 2 to a brake command. By setting the time periods for executing the power on control process and the second brake release preparation process in this manner, even if a short circuit failure occurs in the negative side opening / closing switch 21B, the brake of the brake device 2 on the motor 3 is prevented from being released, and the short circuit failure can be detected.

[0181] Furthermore, as described above, when a short circuit occurs in both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B, an electric path is formed from the positive terminal of the power source 11 through the positive side opening / closing switch 21A, the brake device 2, and the negative side opening / closing switch 21B to the negative terminal of the power source 11. As a result, the voltage of the power source 11 is applied to the brake device 2, and the brake on the motor 3 is released, which is dangerous. Therefore, when the abnormality detection unit 15 determines that a short circuit occurs in both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B, the first protection operation process is executed after the second brake release preparation process.

[0182] In the first protection operation process, the power supply control unit 16 outputs an output off signal as a power supply control signal CTRP to the power supply 11, and the brake control unit 12 outputs a brake control signal BS A and B.S. B The brake lock switch control unit 18 outputs a Low signal which is a brake lock control signal for the brake lock switch 17, and outputs a close signal which controls the brake lock switch 17 to close. As a result, the power supply 11 does not output a DC voltage, i.e., the DC output voltage of the power supply 11 is 0 V, and the brake lock switch 17 is closed to short-circuit the input terminals of the brake device 2 (i.e., between the positive terminal and the negative terminal of the brake device 2), so that the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. This brings the motor 3 into a brake-activated state, ensuring safety.

[0183] In the second protective operation process, which is a modification of the above-mentioned first protective operation process, as shown in Fig. 26B, the brake lock switch control unit 18 outputs a brake lock control signal that closes the brake lock switch 17, but the power supply control signal CTRP that the power supply control unit 16 outputs to the power supply 11 remains an output-on signal. As a result, the power supply 11 outputs a DC voltage of 24 V, but the brake lock switch 17 is closed and the input terminals of the brake device 2 (i.e., between the positive and negative terminals of the brake device 2) are short-circuited, so that the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked, and safety is ensured.

[0184] In a third protective operation process which is a modification of the above-mentioned first protective operation process, as shown in Fig. 27, the power supply control unit 16 outputs an output off signal as the power supply control signal CTRP to the power supply 11, but the brake lock control signal output by the brake lock switch control unit 18 to the brake lock switch 17 remains an open signal. As a result, the brake lock switch 17 remains open, and therefore the input terminals of the brake device 2 (i.e., between the positive and negative terminals of the brake device 2) are not short-circuited, but the power supply 11 does not output a DC voltage, i.e., the DC output voltage of the power supply 11 is 0V, and therefore the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. As a result, the motor 3 is braked, and safety is ensured.

[0185] Next, a protective operation process in the case where a device having an external power source shorts out to the brake cable of the brake device 2 in the brake control device 1 according to the fifth embodiment of the present disclosure will be described.

[0186] FIG. 28 is a diagram showing a case where a device having an external power supply is shorted to a brake cable of a brake device in a brake control device according to a fifth embodiment of the present disclosure and a motor drive device including the same. FIG. 29A is a diagram showing an example of each signal and a brake state when a device having an external power supply is shorted to a brake cable of a brake device as shown in FIG. 28 in a brake control device according to a fifth embodiment of the present disclosure and a motor drive device including the same, and shows an example of each signal and a brake state when a protective operation process is not performed. FIG. 29B is a diagram showing an example of each signal and a brake state when a device having an external power supply is shorted to a brake cable of a brake device as shown in FIG. 28 in a brake control device according to a fifth embodiment of the present disclosure and a motor drive device including the same, and shows an example of each signal and a brake state when a protective operation process is performed. Note that the "brake control signal" is written as "brake signal" in FIG. 29A and FIG. 29B in order to simplify the drawings.

[0187] As shown in Fig. 28, a short circuit may occur in which the positive side of the external power source 6 comes into contact with the brake cable connecting the positive terminal of the braking device 2 and the source of the positive side switching switch 21A, and the negative side of the external power source 6 comes into contact with the brake cable connecting the negative terminal of the braking device 2 and the drain of the negative side switching switch 21B. The external power source 6 is different from the power source 11. In this case, regardless of the operating state of the brake control device 1, the brake cable connecting the positive terminal of the braking device 2 and the source of the positive side switching switch 21A will be at a positive potential (for example, 12 V), and the brake cable connecting the negative terminal of the braking device 2 and the drain of the negative side switching switch 21B will be at 0 V.

[0188] 29A, when a protective operation is not performed, the positive side switch 21A and the negative side switch 21B are both in an open state during the brake operation process, but since the brake cable connecting the positive terminal of the brake device 2 and the source of the positive side switch 21A is at a positive potential (for example, 12V), a current flows through the voltage dividing resistors R1A and R2A in the state detection unit 14, causing the light emitting element in the photocoupler 41A to emit light, and therefore the output side of the photocoupler 41A becomes Low. Therefore, the state detection signal FB A becomes Low. In addition, the voltage of the external power source 6 is applied to the brake coil 115 of the brake device 2, and the brake for the motor 3 is released even though the brake activation process is being executed, which is dangerous. Therefore, the abnormality detection unit 15 detects the state detection signal FB A is the normal state detection signal FB A When the state detection signal FB A becomes Low), it is determined that an abnormality has occurred, and an alarm signal is output. Furthermore, if the abnormality detection unit 15 determines that an abnormality has occurred during the brake actuation processing period, as shown in Fig. 29B, the brake lock switch control unit 18 outputs a close signal to the brake lock switch 17 as a brake lock control signal for the brake lock switch 17, which controls the brake lock switch 17 to be closed. As a result, the brake lock switch 17 is closed and the input terminals of the brake device 2 (i.e., between the positive terminal and the negative terminal of the brake device 2) are short-circuited, so that the voltage of the power source 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked, and safety is ensured.

[0189] 29A, when a protective operation is not performed, the positive side switch 21A is in a closed state and the negative side switch 21B is in an open state in the first brake release preparation process, but since the brake cable connecting the positive terminal of the brake device 2 and the source of the positive side switch 21A is at a positive potential (for example, 12 V), a current flows through the voltage dividing resistors R1A and R2A in the state detection unit 14, causing the light emitting element in the photocoupler 41A to emit light, and therefore the output side of the photocoupler 41A becomes Low. Therefore, the state detection signal FB indicating the potential state of the electric path from the source of the positive side switch 21A to the positive terminal of the brake device 2 A becomes Low. In addition, the voltage of the external power source 6 is applied to the brake coil 115 of the brake device 2, and the brake for the motor 3 is released even though the first brake release preparation process is being executed, which is dangerous. Therefore, the abnormality detection unit 15 detects the state detection signal FB A is the normal state detection signal FB A When the state detection signal FB A becomes Low), it is determined that an abnormality has occurred, and an alarm signal is output. Furthermore, if the abnormality detection unit 15 determines that an abnormality has occurred during the first brake release preparation processing period, as shown in FIG. 29B, the brake lock switch control unit 18 outputs a closing signal to the brake lock switch 17 as a brake lock control signal for the brake lock switch 17, which controls the brake lock switch 17 to be closed. As a result, the brake lock switch 17 is closed and the input terminals of the brake device 2 (i.e., between the positive terminal and the negative terminal of the brake device 2) are short-circuited, and therefore the voltage of the power source 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked, and safety is ensured.

[0190] 29A, when a protection operation is not performed, the positive side switch 21A is in a closed state and the negative side switch 21B is in an open state during the power-on control process, but since the brake cable connecting the negative terminal of the brake device 2 and the drain of the negative side switch 21B is at 0V, no current flows through the voltage dividing resistors R1B and R2B in the state detection unit 14, so the light emitting element in the photocoupler 41B does not emit light, and therefore the output side of the photocoupler 41B is High. Therefore, the state detection signal FB indicating the potential state of the electric path from the negative terminal of the brake device 2 to the drain of the negative side switch 21B B In addition, since the voltage of the external power source 6 is applied to the brake coil 115 of the brake device 2, the brake for the motor 3 is released even though the power-on control process is being executed, which is dangerous. Therefore, the abnormality detection unit 15 detects the state detection signal FB B is the normal state detection signal FB B When the state detection signal FB B becomes High), it is determined that an abnormality has occurred, and an alarm signal is output. Also, when the abnormality detection unit 15 determines that an abnormality has occurred during the power-on control processing period, as shown in FIG. 29B, the power supply control unit 16 outputs an output-off signal as the power supply control signal CTRP to the power supply 11, and the brake lock switch control unit 18 outputs a close signal to the brake lock switch 17 as the brake lock control signal to the brake lock switch 17, which controls the brake lock switch 17 to be closed. As a result, the brake lock switch 17 is closed and the input terminals of the brake device 2 (i.e., between the positive terminal and the negative terminal of the brake device 2) are short-circuited, and therefore the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked, and safety is ensured.

[0191] 29A, when a protective operation is not performed, the positive side switch 21A and the negative side switch 21B are both in an open state in the second brake release preparation process, but since the brake cable connecting the source of the positive side switch 21A and the positive terminal of the brake device 2 is at a positive potential (for example, 12 V), a current flows through the voltage dividing resistors R1A and R2A in the state detection unit 14, causing the light emitting element in the photocoupler 41A to emit light, and therefore the output side of the photocoupler 41A becomes Low. Therefore, the state detection signal FB A becomes Low. In addition, since the voltage of the external power source 6 is applied to the brake coil 115 of the brake device 2, the brake for the motor 3 is released even though the second brake release preparation process is being executed, which is dangerous. Therefore, the abnormality detection unit 15 detects the state detection signal FB A is the normal state detection signal FB A When the state detection signal FB A becomes Low), it is determined that an abnormality has occurred, and an alarm signal is output. Furthermore, if the abnormality detection unit 15 determines that an abnormality has occurred during the second brake release preparation processing period, as shown in FIG. 29B, the brake lock switch control unit 18 outputs a closing signal to the brake lock switch 17 as a brake lock control signal for the brake lock switch 17, which controls the brake lock switch 17 to be closed. As a result, the brake lock switch 17 is closed and the input terminals of the brake device 2 (i.e., between the positive terminal and the negative terminal of the brake device 2) are short-circuited, and therefore the voltage of the power source 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked, and safety is ensured.

[0192] If a cable short circuit with the external power source 6 occurs during the first brake release preparation process period, the power-on control process period, and the second brake release preparation process period, the brake on the motor 3 may be released, resulting in a dangerous state. Therefore, the time period for executing the first brake release preparation process in response to a brake command may be set to a time shorter than the response time of the brake device 2. Similarly, the time period for executing the power-on control process may be set to a time shorter than the response time of the brake device 2 in response to a brake command. Similarly, the time period for executing the second brake release preparation process is set to a time shorter than the response time of the brake device 2. By setting the time periods for executing the first brake release preparation process, the power-on control process, and the second brake release preparation process in this manner, even if a short circuit failure occurs in the negative side opening / closing switch 21B, the brake of the brake device 2 on the motor 3 is prevented from being released, and the short circuit failure can be detected in a state.

[0193] FIG. 30 is a diagram showing a case where a device having an external power supply is shorted to a brake cable of a brake device in a brake control device according to a fifth embodiment of the present disclosure and a motor drive device including the same. FIG. 31A is a diagram showing an example of each signal and a brake state when a device having an external power supply is shorted to a brake cable of a brake device as shown in FIG. 30 in a brake control device according to a fifth embodiment of the present disclosure and a motor drive device including the same, and shows an example of each signal and a brake state when a protective operation process is not performed. FIG. 31B is a diagram showing an example of each signal and a brake state when a device having an external power supply is shorted to a brake cable of a brake device as shown in FIG. 30 in a brake control device according to a fifth embodiment of the present disclosure and a motor drive device including the same, and shows an example of each signal and a brake state when a protective operation process is performed. Note that the "brake control signal" is written as "brake signal" in FIG. 31A and FIG. 31B in order to simplify the drawings.

[0194] As shown in FIG. 30, a short circuit may occur in which the negative side of the external power source 6 comes into contact with the brake cable connecting the positive terminal of the brake device 2 and the source of the positive side switch 21A, and the positive side of the external power source 6 comes into contact with the brake cable connecting the negative terminal of the brake device 2 and the drain of the negative side switch 21B. The external power source 6 is different from the power source 11. In this case, regardless of the operating state of the brake control device 1, the brake cable connecting the positive terminal of the brake device 2 and the source of the positive side switch 21A becomes 0V, and the brake cable connecting the negative terminal of the brake device 2 and the drain of the negative side switch 21B becomes a positive potential (for example, 12V). In addition, when the external power source 6 can be considered to be the same as the power source 11, it is sufficient to execute the protective operation when both the positive side switch 21A and the negative side switch 21B have a short circuit failure, as described above.

[0195] As shown in Fig. 31A, when a protective operation is not performed, the positive side switch 21A and the negative side switch 21B are both in an open state during the brake operation process, but since the brake cable connecting the negative terminal of the brake device 2 and the drain of the negative side switch 21B is at a positive potential (for example, 12V), a current flows through the voltage dividing resistors R1B and R2B in the state detection unit 14, causing the light emitting element in the photocoupler 41B to emit light, and therefore the output side of the photocoupler 41B becomes Low. Therefore, the state detection signal FB indicating the potential state of the electric path from the negative terminal of the brake device 2 to the drain of the negative side switch 21B B becomes Low. In addition, the voltage of the external power source 6 is applied to the brake coil 115 of the brake device 2, and the brake for the motor 3 is released even though the brake activation process is being executed, which is dangerous. Therefore, the abnormality detection unit 15 detects the state detection signal FB B is the normal state detection signal FB B When the state detection signal FB Bbecomes Low), it is determined that an abnormality has occurred, and an alarm signal is output. Furthermore, if the abnormality detection unit 15 determines that an abnormality has occurred during the brake actuation processing period, as shown in Fig. 31B, the brake lock switch control unit 18 outputs a close signal to the brake lock switch 17 as a brake lock control signal for the brake lock switch 17, which controls the brake lock switch 17 to be closed. As a result, the brake lock switch 17 is closed and the input terminals of the brake device 2 (i.e., between the positive terminal and the negative terminal of the brake device 2) are short-circuited, so that the voltage of the power source 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked, and safety is ensured.

[0196] When no protective operation is performed as shown in Fig. 31A, in the first brake release preparation process, the positive side switch 21A is in a closed state and the negative side switch 21B is in an open state, but since the brake cable connecting the negative terminal of the brake device 2 and the drain of the negative side switch 21B is at a positive potential (for example, 12V), a current flows through the voltage dividing resistors R1B and R2B in the state detection unit 14, causing the light emitting element in the photocoupler 41B to emit light, and therefore the output side of the photocoupler 41A becomes Low. Therefore, the state detection signal FB indicating the potential state of the electric path from the negative terminal of the brake device 2 to the drain of the negative side switch 21B B becomes Low. In addition, the voltage of the external power source 6 is applied to the brake coil 115 of the brake device 2, and the brake for the motor 3 is released even though the first brake release preparation process is being executed, which is dangerous. Therefore, the abnormality detection unit 15 detects the state detection signal FB B is the normal state detection signal FB B When the state detection signal FB Abecomes Low), it is determined that an abnormality has occurred, and an alarm signal is output. Furthermore, if the abnormality detection unit 15 determines that an abnormality has occurred during the first brake release preparation processing period, as shown in FIG. 31B, the brake lock switch control unit 18 outputs a closing signal to the brake lock switch 17 as a brake lock control signal for the brake lock switch 17, which controls the brake lock switch 17 to be closed. As a result, the brake lock switch 17 is closed and the input terminals of the brake device 2 (i.e., between the positive terminal and the negative terminal of the brake device 2) are short-circuited, and therefore the voltage of the power source 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked, and safety is ensured.

[0197] 31A, when a protection operation is not performed, the positive side switch 21A is in a closed state and the negative side switch 21B is in an open state in the power-on control process, but since the brake cable connecting the source of the positive side switch 21A and the positive terminal of the brake device 2 is at 0V, no current flows through the voltage dividing resistors R1A and R2A in the state detection unit 14, so the light emitting element in the photocoupler 41A does not emit light, and therefore the output side of the photocoupler 41A becomes High. A In addition, since the voltage of the external power source 6 is applied to the brake coil 115 of the brake device 2, the brake for the motor 3 is released even though the power-on control process is being executed, which is dangerous. Therefore, the abnormality detection unit 15 detects the state detection signal FB A is the normal state detection signal FB A When the state detection signal FB Abecomes High), it is determined that an abnormality has occurred, and an alarm signal is output. Also, when the abnormality detection unit 15 determines that an abnormality has occurred during the power-on control processing period, as shown in FIG. 31B, the power supply control unit 16 outputs an output-off signal as the power supply control signal CTRP to the power supply 11, and the brake lock switch control unit 18 outputs a close signal to the brake lock switch 17 as the brake lock control signal to the brake lock switch 17, which controls the brake lock switch 17 to be closed. As a result, the brake lock switch 17 is closed and the input terminals of the brake device 2 (i.e., between the positive terminal and the negative terminal of the brake device 2) are short-circuited, and therefore the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked, and safety is ensured.

[0198] As shown in Fig. 31A, when a protective operation is not performed, in the second brake release preparation process, both the positive side opening / closing switch 21A and the negative side opening / closing switch 21B are in an open state, but since the brake cable connecting the negative terminal of the brake device 2 and the drain of the negative side opening / closing switch 21B is at a positive potential (for example, 12V), a current flows through the voltage dividing resistors R1B and R2B in the state detection unit 14, causing the light emitting element in the photocoupler 41B to emit light, and therefore the output side of the photocoupler 41B becomes Low. Therefore, the state detection signal FB indicating the potential state of the electric path from the negative terminal of the brake device 2 to the drain of the negative side opening / closing switch 21B B becomes Low. In addition, since the voltage of the external power source 6 is applied to the brake coil 115 of the brake device 2, the brake for the motor 3 is released even though the second brake release preparation process is being executed, which is dangerous. Therefore, the abnormality detection unit 15 detects the state detection signal FB B is the normal state detection signal FB B When the state detection signal FB Bbecomes Low), it is determined that an abnormality has occurred, and an alarm signal is output. Furthermore, if the abnormality detection unit 15 determines that an abnormality has occurred during the second brake release preparation processing period, as shown in FIG. 31B, the brake lock switch control unit 18 outputs a closing signal to the brake lock switch 17 as a brake lock control signal for the brake lock switch 17, which controls the brake lock switch 17 to be closed. As a result, the brake lock switch 17 is closed and the input terminals of the brake device 2 (i.e., between the positive terminal and the negative terminal of the brake device 2) are short-circuited, and therefore the voltage of the power source 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked, and safety is ensured.

[0199] As described above, according to the brake control device 1 according to the fifth embodiment of the present disclosure, only when no abnormality occurs, it is possible to release the brake applied by the brake device 2 applied to the motor 3. Furthermore, even if an abnormality occurs when releasing the brake applied by the brake device 2 applied to the motor 3, it is possible to avoid a situation in which the brake is released.

[0200] Next, a sixth embodiment of the present disclosure will be described. The sixth embodiment of the present disclosure further includes a brake lock switch that shorts the input terminals of the brake device 2 when an abnormality occurs and a brake lock switch control unit including the brake lock switch in the third embodiment.

[0201] FIG. 32 is a diagram illustrating a brake control device and a motor drive device including the brake control device according to the sixth embodiment of the present disclosure.

[0202] The brake control device 1 according to the sixth embodiment further includes a brake lock switch 17 and a brake lock switch control unit 18 in addition to the components of the brake control device 1 according to the third embodiment shown in FIG.

[0203] The brake lock switch 17 is connected between the input terminals of the brake device 2 (i.e., between the positive and negative terminals of the brake device 2) so as to be connected in parallel to the brake device 2, and opens and closes an electric path in response to the received brake lock control signal. In the example shown in FIG. 32, one brake lock switch 17 is provided, but two or more brake lock switches connected in series may be provided, and in this case, these brake lock switches are controlled to open and close by the same brake lock switch control signal. The brake lock switch 17 may be configured as a semiconductor switching element or a mechanical switch. Examples of the semiconductor switching element constituting the brake lock switch 17 include FET, IGBT, thyristor, GTO, transistor, etc., but other semiconductor switching elements may also be used. In the example shown in FIG. 32, as an example, the brake lock switch 17 is a normally-off semiconductor switching element.

[0204] The brake lock switch control unit 18 outputs a close signal as a brake lock control signal to the brake lock switch 17 to control the brake lock switch 17 to close when an abnormality is detected by the abnormality detection unit 15, and outputs an open signal to control the brake lock switch 17 to open when no abnormality is detected by the abnormality detection unit 15.

[0205] The brake lock switch control unit 18 is provided in an arithmetic processing device (processor) provided in the brake control device 1. The brake lock switch control unit 18 of the arithmetic processing device is, for example, a functional module realized by a computer program executed on the processor. For example, when the brake lock switch control unit 18 is constructed in the form of a computer program, the function of the brake lock switch control unit 18 can be realized by operating the arithmetic processing device according to the computer program. The computer program for executing the processing of the brake lock switch control unit 18 may be provided in a form recorded on a computer-readable recording medium such as a semiconductor memory, a magnetic recording medium, or an optical recording medium. Alternatively, the brake lock switch control unit 18 may be realized as a semiconductor integrated circuit in which a computer program for realizing the function is written.

[0206] Figures 33A, 33B, 34A, 34B, and 34C are diagrams illustrating the signals and brake states in the brake control device according to the sixth embodiment of the present disclosure. In Figures 33A, 33B, 34A, 34B, and 34C, in order to simplify the drawings, the "brake control signal" is written as "brake signal" and "power-on control process." In the following description, as an example, the open / close switch 22 is a normally open switch.

[0207] FIG. 33A is a first embodiment of the present disclosure. 6 FIG. 33B is a diagram illustrating each signal and brake state in the brake control device according to the embodiment of the present disclosure, in which FIG. 33A illustrates each signal and brake state in a normal state. 6 FIG. 34A is a diagram illustrating the signals and brake states in the brake control device according to the embodiment, and illustrates the signals and brake states when a short circuit occurs in an open / close switch. 6 FIG. 34B is a diagram illustrating the signals and brake states in the brake control device according to the embodiment, and illustrates the signals and brake states when a first protective operation process is performed when a short circuit occurs in an open / close switch.6 FIG. 34C is a diagram illustrating the signals and brake states in the brake control device according to the embodiment, and illustrates the signals and brake states when a second protective operation process is performed when a short circuit occurs in the open / close switch. 6 FIG. 11 is a diagram illustrating examples of signals and brake states in the brake control device according to the embodiment, and illustrates examples of signals and brake states when a third protective operation process is performed when a short circuit occurs in an open / close switch.

[0208] First, a case where there is no abnormality in any of the devices in the brake control device 1 according to the sixth embodiment of the present disclosure will be described with reference to FIG. 33A.

[0209] In the brake actuation process, the power supply control unit 16 outputs an output off signal, the brake control unit 12 outputs a brake control signal BS for controlling the open / close switch 22 to be opened, and the brake lock switch control unit 18 outputs a brake lock control signal for controlling the open / close switch 17 to be opened. Since the open / close switch 22 is a normally open switch, the brake control unit 12 outputs a Low signal as the brake control signal BS for the open / close switch 22. The power supply 11 that has received the output off signal does not output a DC voltage, that is, the DC output voltage of the power supply 11 becomes 0V. Furthermore, since the open / close switch 22 is opened by the brake actuation process, the electric path from the positive terminal of the power supply 11 through the brake device 2 to the negative terminal of the power supply 11 is cut off. Therefore, if there is no abnormality in each device in the brake control device 1, the brake control unit 12 executes the brake actuation process, and the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked. In addition, since no current flows through the voltage dividing resistors R1C and R2C in the state detection unit 14, the light emitting element in the photocoupler 41C does not emit light, and therefore the output side of the photocoupler 41C becomes High. Therefore, the state detection signal FB, which indicates the potential state of the electric path between the drain of the open / close switch 22 and the negative terminal of the brake device 2, becomes High.

[0210] The power-on control process is executed between the brake activation process and the brake release process when the brake activation process is switched to the brake release process. During the power-on control process, the power supply control unit 16 outputs an output-on signal as the power supply control signal CTRP to the power supply 11, the brake control unit 12 outputs a brake control signal BS for controlling the open / close switch 22 to be opened, and the brake lock switch control unit 18 outputs a brake lock control signal for controlling the brake lock switch 17 to be opened. Since the open / close switch 22 is a normally open switch, the brake control unit 12 outputs a low signal as the brake control signal BS to the open / close switch 22. A direct current voltage (a direct current voltage of 24V in the example shown in FIG. 32) is output from the power supply 11 that has received the output-on signal. Since the open / close switch 22 is open, the electric path from the positive terminal of the power supply 11 through the brake device 2 to the negative terminal of the power supply 11 is interrupted. Therefore, if there is no abnormality in each device in the brake control device 1, the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is in a brake-activated state. Furthermore, the electric path from the positive terminal of the power source 11 through the brake device 2 to the drain of the open / close switch 22 has the same potential as the voltage output by the positive terminal of the power source 11 (24 V in the example shown in FIG. 32). As a result, a current flows through the voltage dividing resistors R1C and R2C in the state detection unit 14, causing the light emitting element in the photocoupler 41C to emit light, and therefore the output side of the photocoupler 41C becomes Low. As a result, the state detection signal FB, which indicates the potential state of the electric path between the drain of the open / close switch 22 and the negative terminal of the brake device 2, becomes Low.

[0211] The brake release process is executed after the power-on control process. During the brake release process, the power supply control unit 16 outputs an output-on signal as the power supply control signal CTRP to the power supply 11, the brake control unit 12 outputs a brake control signal BS for controlling the open / close switch 22 to be closed, and the brake lock switch control unit 18 outputs a brake lock control signal for controlling the brake lock switch 17 to be opened. Since the open / close switch 22 is a normally open switch, the brake control unit 12 outputs a High signal as the brake control signal BS to the open / close switch 22. If there is no abnormality in each device in the brake control device 1, a DC voltage (a DC voltage of 24 V in the example shown in FIG. 32) is output from the power supply 11. Since the open / close switch 22 is closed by the brake release process, an electric path is formed from the positive terminal of the power supply 11 through the brake device 2 to the negative terminal of the power supply 11. Therefore, if there is no abnormality in the open / close switch 22 and the devices related thereto, the brake control unit 12 executes the brake release process, and the voltage of the power supply 11 is applied to the brake coil 115 of the brake device 2. As a result, the brake applied to the motor 3 is released. In addition, the electric potential of the electric path from the negative terminal of the brake device 2, via the open / close switch 22, to the negative terminal of the power source 11 is the same as 0V, which is the electric potential of the negative terminal of the power source 11. As a result, no current flows through the voltage dividing resistors R1C and R2C in the state detection unit 14, so the light emitting element in the photocoupler 41C does not emit light, and therefore the output side of the photocoupler 41C is High. As a result, the state detection signal FB, which indicates the electric potential state of the electric path between the drain of the open / close switch 22 and the negative terminal of the brake device 2, is High.

[0212] When there is no abnormality in the above-mentioned open / close switch 22 and related devices and the power supply 11, that is, when normal, the state detection signal FB A and F.B. B The contents of the above are stored in advance in the abnormality detection unit 15 so that they can be used in the abnormality detection process described later.

[0213] Next, a case where a short circuit failure occurs in the open / close switch 22 will be described with reference to FIG. 33B.

[0214] When a short circuit failure occurs in the open / close switch 22, the state detection signal FB output from the state detection unit 14 during the power-on control processing period becomes different from the signal state during normal operation. That is, during the power-on control processing period, the open / close switch 22 is opened under normal operation, but when a short circuit failure occurs in the open / close switch 22, the open / close switch 22 becomes the same state as when it is closed. During the power-on control processing period, the power source 11 that receives the output-on signal outputs a DC voltage (a DC voltage of 24 V in the example shown in FIG. 32). Since the open / close switch 22 becomes the closed state due to the short circuit failure of the open / close switch 22, an electric path is formed from the positive terminal of the power source 11 through the brake device 2 to the negative terminal of the power source 11. The electric path from the negative terminal of the brake device 2 through the open / close switch 22 to the negative terminal of the power source 11 becomes the same potential as 0 V, which is the potential of the negative terminal of the power source 11. As a result, no current flows through the voltage dividing resistors R1C and R2C in the state detection unit 14, so the light emitting element in the photocoupler 41C does not emit light, and the output side of the photocoupler 41C becomes High. As a result, the state detection signal FB, which indicates the potential state of the electric path between the drain of the open / close switch 22 and the negative terminal of the brake device 2, becomes High.

[0215] In this way, when a short circuit failure occurs in the open / close switch 22, the state detection signal FB output from the state detection unit 14 during the power-on control process becomes different from the signal state during normal operation. The abnormality detection unit 15 detects the presence or absence of a short circuit failure in the open / close switch 22 based on a combination of the contents of the brake control signal BS and the contents of the state detection signal FB during the execution of the power-on control process. More specifically, when the state detection signal FB is Low during the execution of the power-on control process, the abnormality detection unit 15 determines that a short circuit failure has not occurred in the open / close switch 22, and when the state detection signal FB is High, the abnormality detection unit 15 determines that an abnormality has occurred (i.e., a short circuit failure in the open / close switch 22). When the abnormality detection unit 15 detects the occurrence of an abnormality during the execution of the power-on control process, it outputs an alarm signal.

[0216] Next, a case where the first protective operation process is performed when the open / close switch 22 has a short circuit fault will be described with reference to FIG. 34A.

[0217] When the abnormality detection unit 15 determines that a short circuit failure has occurred in the open / close switch 22, a first protective operation process is executed after a power-on control process.

[0218] In the first protection operation process, the power supply control unit 16 outputs an output off signal as the power supply control signal CTRP to the power supply 11, and the brake lock switch control unit 18 outputs a close signal as a brake lock control signal to the brake lock switch 17 to control the brake lock switch 17 to close. As a result, the power supply 11 does not output a DC voltage, i.e., the DC output voltage of the power supply 11 becomes 0V, and furthermore, the brake lock switch 17 is closed to short-circuit the input terminals of the brake device 2 (i.e., between the positive terminal and the negative terminal of the brake device 2), so that the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked, and safety is ensured.

[0219] In the second protective operation process, which is a modification of the above-mentioned first protective operation process, as shown in Fig. 34B, the brake lock switch control unit 18 outputs a brake lock control signal that closes the brake lock switch 17, but the power supply control signal CTRP that the power supply control unit 16 outputs to the power supply 11 remains an output-on signal. As a result, the power supply 11 outputs a DC voltage of 24 V, but the brake lock switch 17 is closed and the input terminals of the brake device 2 (i.e., between the positive and negative terminals of the brake device 2) are short-circuited, so that the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked, and safety is ensured.

[0220] In a third protective operation process which is a modification of the above-mentioned first protective operation process, as shown in Fig. 34C, the power supply control unit 16 outputs an output off signal as the power supply control signal CTRP to the power supply 11, but the brake lock control signal output by the brake lock switch control unit 18 to the brake lock switch 17 remains an open signal. As a result, the brake lock switch 17 remains open, so that the input terminals of the brake device 2 (i.e., between the positive and negative terminals of the brake device 2) are not short-circuited, but the power supply 11 does not output a DC voltage, i.e., the DC output voltage of the power supply 11 is 0V, so that the voltage of the power supply 11 is not applied to the brake coil 115 of the brake device 2. As a result, the motor 3 is braked, and safety is ensured.

[0221] As described above, according to the brake control device 1 according to the sixth embodiment of the present disclosure, only when no abnormality occurs, it is possible to release the brake applied by the brake device 2 applied to the motor 3. Furthermore, even if an abnormality occurs when releasing the brake applied by the brake device 2 applied to the motor 3, it is possible to avoid a situation in which the brake is released.

[0222] In the fifth and sixth embodiments described above, the brake lock switch 17 is configured as a normally open switch, but as an alternative, the brake lock switch 17 may be configured as a normally closed switch. By configuring the brake lock switch 17 as a normally closed switch, even if the power supply to the drive circuit of the normally closed brake lock switch 17 is lost for some reason, the input terminals of the brake device 2 (i.e., between the positive and negative terminals of the brake device 2) are shorted, so that the voltage of the power source 11 is not applied to the brake coil 115 of the brake device 2. Therefore, the motor 3 is braked, and safety is ensured. [Explanation of symbols]

[0223] 1 Brake control device 2 Brake device 3 Motor 11 Power supply 12 Brake control unit 13 Opening and closing section 14 Status detection section 15 Anomaly detection section 16 Power supply control unit 17 Brake lock switch 18 Brake lock switch control section 21A positive side opening and closing switch 21B Negative side opening / closing switch 22 Open / close switch 41A, 41B, 41C Photocouplers 42 Surge absorber 100 Motor drive device 111 Friction plate 112 Armature 113 End plate 114 Spring 115 Brake coil 116 cores 117 Spacer 118 Volts 121 Shaft 122 Hub R1A, R2A, R1B, R2B, R1C, R2C Voltage divider resistors R3A, R3B, R3C Pull-up resistors

Claims

1. A brake control device that controls a non-excitation actuation type brake device that activates a brake when there is no voltage applied and releases the brake when there is an excitation when the voltage is applied, a power supply that is controlled to output a voltage or not output the voltage in response to a received power supply control signal; A brake control unit that outputs a brake control signal; a switching unit connected in series to the brake device and configured to open and close an electric path between the power source and the brake device in response to the received brake control signal; a state detection unit that outputs a state detection signal indicating a potential state of an electric path between the opening / closing unit and the brake device; an abnormality detection unit that detects whether or not an abnormality has occurred based on a combination of the contents of the brake control signal and the contents of the state detection signal; a power supply control unit that outputs, as the power supply control signal for the power supply, an output off signal that controls the power supply so as not to output the voltage when an abnormality is detected by the abnormality detection unit; Equipped with the opening / closing unit has at least one positive side opening / closing switch which opens and closes an electric path between a positive terminal of the power source and a positive terminal of the brake device, and at least one negative side opening / closing switch which opens and closes an electric path between a negative terminal of the power source and a negative terminal of the brake device, the brake control unit executes a brake activation process that outputs the brake control signal for controlling the positive side opening / closing switch and the negative side opening / closing switch to be opened, a brake release process that outputs the brake control signal for controlling the positive side opening / closing switch and the negative side opening / closing switch to be closed, and a brake release preparation process that outputs the brake control signal for controlling the positive side opening / closing switch to be closed and the negative side opening / closing switch to be opened between the brake activation process and the brake release process when transitioning from the brake activation process to the brake release process, The abnormality detection unit detects whether or not an abnormality has occurred based on a combination of the contents of the brake control signal and the contents of the state detection signal during the execution of the brake activation process and the execution of the brake release preparation process, A brake control device, wherein the power supply control unit outputs the output off signal when the abnormality detection unit detects an occurrence of an abnormality both during execution of the brake activation process and during execution of the brake release preparation process.

2. 2. The brake control device according to claim 1, wherein the power supply control unit outputs, as the power supply control signal for the power supply, an output on signal that controls the power supply to output the voltage when no occurrence of an abnormality is detected by the abnormality detection unit.

3. The brake control device according to claim 1 , wherein, when the abnormality detection unit does not detect the occurrence of an abnormality during execution of the brake release preparation process, the brake control unit ends the brake release preparation process and executes the brake release process.

4. The abnormality detection unit detects whether or not an abnormality has occurred based on a combination of the contents of the brake control signal and the contents of the state detection signal during execution of the brake actuation process, The brake control device according to claim 1 , wherein the abnormality detection unit outputs an alarm signal when it detects an occurrence of an abnormality during execution of the brake actuation process.

5. The abnormality detection unit while the power supply control unit is outputting the output off signal before executing the brake release preparation process when transitioning from the brake activation process to the brake release preparation process, detects whether or not an abnormality has occurred in the power supply based on a combination of the contents of the brake control signal, the contents of the state detection signal, and the contents of the power supply control signal; 5. The brake control device according to claim 1, further comprising: a power supply control unit that outputs an alarm signal when an abnormality in the power supply is detected.

6. 6. The brake control device according to claim 5, wherein when transitioning from the brake actuation process through the brake release preparation process to the brake release process, if at least one of the occurrence of an abnormality that is to be detected by the abnormality detection unit during execution of the brake actuation process, the occurrence of an abnormality that is to be detected by the abnormality detection unit during execution of the brake release preparation process, and the occurrence of an abnormality in the power source is not detected, the brake control unit terminates the brake release preparation process and executes the brake release process.

7. The abnormality detection unit while the power supply control unit is outputting the output off signal before executing the brake application process when transitioning from the brake release process to the brake application process, detects whether or not an abnormality has occurred in the power supply based on a combination of the contents of the brake control signal, the contents of the state detection signal, and the contents of the power supply control signal; 7. The brake control device according to claim 1, further comprising: a power supply control unit that outputs an alarm signal when an abnormality in the power supply is detected.

8. the opening / closing unit has at least one opening / closing switch that opens or closes either an electric path between a positive terminal of the power source and a positive terminal of the brake device or an electric path between a negative terminal of the power source and a negative terminal of the brake device, The brake control unit executes a brake activation process that outputs the brake control signal that controls the open / close switch to be opened, and a brake release process that outputs the brake control signal that controls the open / close switch to be closed, The abnormality detection unit detects whether or not an abnormality has occurred based on a combination of the contents of the brake control signal and the contents of the state detection signal during execution of the brake actuation process, 3. The brake control device according to claim 1, wherein the power supply control unit outputs the output off signal when the abnormality detection unit detects the occurrence of an abnormality during execution of the brake actuation process.

9. 9. The brake control device according to claim 8, wherein if the abnormality detection unit does not detect the occurrence of an abnormality during execution of the brake application process when transitioning from the brake application process to the brake release process, the brake control unit terminates the brake application process and executes the brake release process.

10. The brake control device according to claim 8 or 9, wherein the abnormality detection unit outputs an alarm signal when it detects an occurrence of an abnormality during execution of the brake actuation process.

11. the abnormality detection unit detects whether or not an abnormality has occurred in the power supply based on a combination of the contents of the brake control signal, the contents of the state detection signal, and the contents of the power supply control signal while the power supply control unit is outputting the output off signal before executing the brake application process when transitioning from the brake application process to the brake release process; The brake control unit continues execution of the brake activation process when the abnormality detection unit detects an abnormality in the power supply, and terminates the brake activation process and executes the brake release process when the abnormality detection unit does not detect an abnormality in the power supply.

12. The brake control device according to claim 11, wherein the abnormality detection unit outputs an alarm signal when it detects an occurrence of an abnormality in the power supply.

13. a brake lock switch connected between input terminals of the brake device so as to be connected in parallel to the brake device, and opening and closing an electric circuit in response to a received brake lock control signal; a brake lock switch control unit that outputs, as the brake lock control signal for the brake lock switch, a close signal for controlling the brake lock switch to be closed when the abnormality detection unit detects the occurrence of an abnormality, and outputs an open signal for controlling the brake lock switch to be opened when the abnormality detection unit does not detect the occurrence of an abnormality; The brake control device according to any one of claims 1 to 12, further comprising:

14. a non-excitation actuation type brake device that applies a brake to the motor when no voltage is applied and is not excited, and releases the brake to the motor when the voltage is applied and is excited; A brake control device according to any one of claims 1 to 13, which controls the brake device; A motor drive device comprising:

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