Non-excitation working brake

Abstract

A non-excitation service brake (1) uses the magnetic force of a permanent magnet (17) in order to hold an attraction plate (13) at a braking force release position (13A) at which the attraction plate (13) is separated from a friction brake plate (12). When the attraction plate (13) held at the braking force application position (13B) is moved toward the braking force release position (13A) and when the attraction plate (13) held at the braking force release position (13A) is moved toward the braking force application position (13B), only the coil of the electromagnet (16) is energized. Heat generation and power consumption caused by continuous coil energization can be suppressed. By setting the electromagnetic force of the electromagnet (16) to an appropriate value, it is possible to reliably and quickly switch between a braking force application state and a braking force release state.

Description

Technical Field

[0001] This invention relates to a non-excitation working brake, and more specifically, to a permanent magnet-embedded non-excitation working brake that utilizes the magnetic force of a permanent magnet to maintain the braking force release state. Background Technology

[0002] A non-excitation working brake is mounted on a servo motor or similar device as a safety device when not in operation. For example, as described in Patent Document 1, the non-excitation working brake includes a friction brake plate, an attraction plate made of magnetic material, and an electromagnet arranged along the axial direction on the outer periphery of the motor's rotating shaft. The attraction plate, movable along the rotating shaft, is pressed against the friction brake plate, which is integrally rotatably mounted on the rotating shaft, by a spring force, thereby applying braking force to the rotating shaft. If the electromagnet, opposite the attraction plate, is energized, the attraction plate overcomes the spring force with magnetic attraction and moves away from the friction brake plate, releasing the braking force. Generally, a fixed plate is positioned at a fixed location along the axial direction of the rotating shaft in the non-excitation working brake to reliably generate braking force. The attraction plate, movable along the axial direction, is forced towards the fixed plate by the spring force of a pressing spring, across the friction brake plate, which is movable relative to the rotating shaft. If the electromagnet is energized, the attraction plate is attracted, allowing the friction brake plate to rotate freely, and the braking force applied to the rotating shaft is released.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-2617

[0006] Patent Document 2: International Publication No. 2015 / 198399

[0007] Patent Document 3: International Publication No. 2006 / 103727 Summary of the Invention

[0008] Regarding existing non-excitation working brakes, in order to release the braking force when the actuator, motor, etc., are performing operations, the electromagnet is generally supplied with power, such as DC 24V or DC 90V. For the attraction action that moves the attraction plate to the position where the braking force is released, voltage is applied to the coil of the electromagnet, and the electromagnetic force generated at this time attracts the attraction plate, which is made of magnetic material, to pull the attraction plate closer. To maintain the state of brake release, current is continuously flowing in the coil of the electromagnet. That is, the non-excitation working brake serves to stop the rotating shaft of the actuator or motor during emergency stops such as power outages, but outside of emergency stops, a voltage must always be continuously applied.

[0009] The current flowing through the coil of the electromagnet causes the wires to heat up, resulting in an overall increase in the temperature of the brake. This increased brake temperature, in turn, raises the temperature of the actuator or motor that houses the brake, thus affecting the winding temperature and the internal temperature of the encoder.

[0010] In view of this, the object of the present invention is to provide a non-excitation type brake that can maintain the braking force release state without the continuous flow of current in the coil of the electromagnet, so as to suppress the heat generation and power consumption caused by the coil being energized.

[0011] The non-excitation working brake of the present invention is characterized by comprising:

[0012] A friction brake plate is mounted on the rotating shaft of the object to which the braking force is applied and rotates integrally with the rotating shaft;

[0013] An attraction plate, which is movable between a braking force application position pressed against the friction brake plate and a braking force release position away from the friction brake plate, and is made of a magnetic material;

[0014] The pressing spring generates a holding spring force that holds the attraction plate in the position where the braking force is applied;

[0015] A permanent magnet that generates a holding magnetic force to keep the attraction plate in the braking release position;

[0016] An electromagnet capable of generating an electromagnetic force to move the attraction plate; and

[0017] A braking control circuit drives and controls the electromagnet in such a way that when the power is cut off, the attraction plate held in the braking force release position moves toward the braking force application position, and when the power is turned on, the attraction plate held in the braking force application position moves toward the braking force release position.

[0018] Here, the braking control circuit can be configured as follows, comprising:

[0019] The power monitoring unit monitors the power supply;

[0020] The charging unit stores the power used to excite the electromagnet;

[0021] The coil voltage control unit, when the power monitoring unit detects that the power supply has been cut off, instantaneously energizes the coil of the electromagnet in the direction of counteracting the holding magnetic force of the permanent magnet by using the power supplied from the charging unit in order to move the attraction plate from the braking force release position toward the braking force application position; and

[0022] The attraction / release detection unit detects the attraction and release actions of the attraction plate.

[0023] In this case, the coil voltage control unit is configured such that when the power supply monitoring unit detects that the power supply has been turned on, in order to perform the charging operation of the charging unit and to move the attraction plate from the braking force application position to the braking force release position, the coil of the electromagnet is momentarily energized to generate an electromagnetic force for attracting the attraction plate.

[0024] In addition, the magnetic attraction of the permanent magnet can be used to attract and hold the attraction plate in the braking release position, and the holding force can be increased by continuously energizing the coil of the electromagnet with a low voltage.

[0025] Invention Effects

[0026] In this invention, the magnetic attraction of a permanent magnet is used to hold the attraction plate in the braking release position away from the friction brake plate. The coil of the electromagnet can be energized only when the attraction plate, held in the braking application position, is moved towards the braking release position, and when the attraction plate, held in the braking release position, is moved towards the braking application position. Therefore, heat generation and power consumption caused by continuous coil energization can be suppressed. Furthermore, by setting the holding spring force, the holding magnetic force, and the electromagnetic force of the electromagnet to appropriate values, the switching between braking application and braking release can be performed reliably and quickly. Attached Figure Description

[0027] Figure 1 (A) is a schematic block diagram showing the non-excitation working brake of the present invention assembled in a motor system. Figure 1 (B) is a schematic half-sectional view showing its braking mechanism section.

[0028] Figure 2 (A) is a summary flowchart showing the operation (attraction action of the attraction plate) of the de-energized working brake when the power is turned on. Figure 2 (B) is an explanatory diagram showing the state of the braking mechanism of the non-excited working brake as it transitions from the initial state to the state of brake release (attraction of the attraction plate is complete).

[0029] Figure 3 (A) is a summary flowchart showing the operation (release action of the suction plate) when the power supply to the de-energized working brake is cut off. Figure 3 (B) is an explanatory diagram showing the state of the braking mechanism of a non-excited working brake as it transitions from the state of brake release (attraction state of the attraction plate) to the state of brake application (release state of the attraction plate). Detailed Implementation

[0030] Hereinafter, embodiments of the non-excitation working brake of the present invention will be described with reference to the accompanying drawings. The examples described below apply the non-excitation working brake of the present invention to a motor system. Furthermore, the present invention is not limited to the structure of the embodiments described below; the non-excitation working brake can also be applied to various rotary drive systems other than motor systems.

[0031] Figure 1 (A) is a schematic block diagram illustrating the application of the non-excitation actuation type brake according to this embodiment to a motor system. Figure 1 (B) is a schematic half-sectional view showing the braking mechanism of the non-excited working brake. (Refer to...) Figure 1 As described in (A), the motor system 100 includes: a motor 110; an encoder 130 that detects the rotation of the rotating shaft 120 of the motor 110; and a non-excitation working brake 1 for applying braking force to the rotating shaft 120. The non-excitation working brake 1 includes a braking mechanism 10 mounted on the rotating shaft 120 and a braking control circuit 20, and is powered by a power supply 30 such as a DC 24V power supply.

[0032] like Figure 1 As shown in (B), the basic structure of the braking mechanism 10 is the same as that of a general non-excitation working brake, and it is arranged on the outer periphery of the rotating shaft 120. The braking mechanism 10 includes: a fixed plate 11; a friction brake plate 12; an attraction plate 13 (actuator); a pressing spring 15, which is assembled to the magnetic yoke 14; and an electromagnet 16, which is composed of a coil 16a also assembled to the magnetic yoke 14. In addition, the braking mechanism 10 also includes a permanent magnet 17 assembled to the magnetic yoke 14.

[0033] The fixing plate 11 is fixedly disposed at a distance axially spaced from the front end face 14a of the magnetic yoke 14. The friction brake plate 12 is coaxially mounted to the rotating shaft 120 of the object to which the braking force is applied via an annular hub 18, rotates integrally with the rotating shaft 120, and can slide axially through a spline engagement with the hub 18. Annular friction plates are attached to the end faces on both sides of the friction brake plate 12. The attraction plate 13 is made of magnetic material and is axially opposed to the fixing plate 11 across the friction brake plate 12. The attraction plate 13 is supported by a guide shaft 19 extending axially from the front end face 14a of the magnetic yoke, allowing it to slide axially between the braking force release position 13A, which abuts against the front end face 14a of the magnetic yoke, and the braking force application position 13B, which is pressed against the friction brake plate 12.

[0034] The pressing spring 15 is a helical spring and is mounted to the magnetic yoke 14 in such a way that it protrudes axially from the front end face 14a of the magnetic yoke. For example, multiple pressing springs 15 are arranged at equal angular intervals in the circumferential direction, and the spring force of the pressing springs 15 can be used to hold the attraction plate 13 in the braking force application position 13B, which is pressed against the friction brake plate 12, and in this state, a predetermined braking force is applied to the rotating shaft 120. In contrast, the permanent magnet 17 is, for example, a ring-shaped magnet, and is mounted to the magnetic yoke 14 in such a way that its ring-shaped end face protrudes from the front end face 14a of the magnetic yoke. The permanent magnet 17 can use its magnetic attraction to overcome the spring force of the pressing springs 15 and hold the attraction plate 13 in the braking force release position 13A. Alternatively, the permanent magnet 17 can be configured to be mounted on the side of the attraction plate 13.

[0035] The electromagnet 16 can overcome the spring force of the pressing spring 15 and generate an electromagnetic attraction that pulls the attraction plate 13, which is subjected to the force applied to the braking position 13B, toward the braking release position 13A. In addition, by energizing in the opposite direction (the direction that counteracts the magnetic attraction of the permanent magnet 17), the attraction plate 13, which is held in the braking release position 13A by the holding force of the permanent magnet 17, can be released.

[0036] Next, the brake control circuit 20 energizes the electromagnet 16, thereby performing a release action that moves the attraction plate 13, which is held in the brake release position 13A, toward the brake application position 13B, and a attraction action that moves the attraction plate 13, which is subjected to force at the brake application position 13B, toward the brake release position 13A. (Refer to...) Figure 1 As described in (A), the braking control circuit 20 includes a power supply voltage monitoring unit 21 (power monitoring unit), a power release charging unit 22, a coil voltage control unit 24 for driving the electromagnet, and an attraction / release detection unit 23. The power supply voltage monitoring unit 21 monitors the power supply 30 and detects power cut-offs such as power on / off. The power release charging unit 22 stores the power used to excite the electromagnet 16. The attraction / release detection unit 23 detects the magnetic poles formed on the electromagnet 16 based on the current and voltage flowing in the coil 16a of the electromagnet 16 to confirm the attraction and release of the attraction plate 13. Magnetic pole detection can also be performed using a magnetic pole sensor such as a Hall element.

[0037] If the drive power supply is detected to be on, the coil voltage control unit 24 performs a charging operation on the power release charging unit 22. After charging by the power release charging unit 22, the electromagnet 16 is energized to generate an electromagnetic force (magnetic attraction) that moves the attraction plate 13 from the braking force application position 13B toward the braking force release position 13A. Alternatively, if the drive power supply is detected to be off, the electromagnet 16 is energized using the power supplied from the power release charging unit 22, releasing the attraction plate 13 from the attraction of the permanent magnet 17 and moving it from the braking force release position 13A toward the braking force application position 13B. Furthermore, the attraction plate 13 can be held in the braking force release position 13A by simultaneously using the magnetic attraction of the permanent magnet 17 and the electromagnetic attraction of the electromagnet 16. In this case, when the power is on, compared to when the power is off, energizing the electromagnet 16 with lower power can suppress heat generation and power consumption caused by continuous coil energization.

[0038] (When the power is on: the suction action of the suction plate)

[0039] Reference Figure 2 The operation of the non-excitation working brake 1 when the power is turned on is explained. Figure 2 (A) is a summary flowchart showing the operation of the de-energized working brake 1 when the power is turned on. Figure 2 (B) is an explanatory diagram showing the state of the braking mechanism section 10 of the de-energized working brake 1 as it transitions to the braking force release state (the attraction of the attraction plate is completed). If the power is on, the power supply voltage monitoring unit 21 detects that the power is on. Figure 2 Step (A) ST1) performs the charging operation of the power release charging unit 22. Figure 2 (A) Step ST2). The braking mechanism section 10 of the non-excitation working brake 1 is in the position. Figure 2 The state of (B) is B1 (initial state).

[0040] Next, in order to move the suction plate 13 to the braking release position 13A, the initial suction action of the suction plate 13 is performed. Figure 2 (Step ST3 of (A)). The coil voltage control unit 24 momentarily energizes the coil 16a of the electromagnet 16 (24V) to temporarily generate a magnetic attraction force to attract the attraction plate 13. The magnetic attraction force of the permanent magnet 17 and the magnetic attraction force of the electromagnet 16 cause the attraction plate 13 to slide against the spring force of the pressing spring 15, thereby forming a state in which the braking force is released 13A by the front end face 14a of the magnetic yoke. Figure 2 (B) state B2).

[0041] Next, the energization of the electromagnet 16 is stopped (step ST4). The energization status of the electromagnet 16 is confirmed by the attraction / release detection unit 23 and the initial attraction operation is terminated. Figure 2 Step ST5 of (A) Figure 2 (B) State B3). Thereafter, the braking force is maintained in the released state by the magnetic attraction of the permanent magnet 17. In this state, the motor system 100 is driven to rotate the rotating shaft 120.

[0042] Here, in step ST4, the voltage applied to the electromagnet 16 can also be switched to a low voltage, thus switching from a power-saving state to a state where the electromagnet 16 attracts the attraction plate 13. In this case, as... Figure 2 As shown in state B4 of (B), a low voltage is continuously energized to the coil 16a of the electromagnet 16. In this case, the braking force is released by utilizing the magnetic attraction of the permanent magnet 17 and the magnetic attraction of the electromagnet 16.

[0043] (When the power is cut off: the suction plate is released)

[0044] Figure 3 (A) is a summary flowchart showing the operation of switching the de-energized working brake 1 from the braking force release state to the braking force application state when the power supply for the drive is cut off. Figure 3 (B) is an explanatory diagram showing the state of the braking mechanism section 10 as it transitions to the state of applying braking force (the state of releasing the suction plate). First, the state of the braking mechanism section 10 of the de-energized working brake 1 changes to... Figure 3 (B) State B3 or State B4. The power supply voltage monitoring unit 21 detects whether the power supply has been cut off. Figure 3 (A) Step ST11). When the attraction plate 13 is attracted to the braking force release position 13A by the electromagnet 16 in addition to the permanent magnet 17 ( Figure 3 (B) state B4), and also stop energizing the coil of electromagnet 16 ( Figure 3 (A) Step ST12).

[0045] If the coil voltage control unit 24 detects a power cut-off, it instantly energizes the electromagnet 16 using the power supplied from the power release charging unit 22, and releases the attraction plate 13, which is held in the braking force release position 13A by the holding magnetic force of the permanent magnet 17, from the attraction of the permanent magnet 17. Figure 3(Step ST13 of (A)). In this case, the energizing direction of the coil 16a of the electromagnet 16 is controlled to generate magnetic lines of force in the direction that counteract the magnetic force of the permanent magnet 17. This is used as a trigger condition to reverse the magnitude relationship of the force acting on the attraction plate 13 (the attraction force of the pressing spring 15 is less than the attraction force of the permanent magnet 17), and the attraction plate 13 is released from the attraction of the permanent magnet 17 by the spring force of the pressing spring 15, so that the attraction plate 13 slides from the braking force release position 13A toward the friction brake plate 12 and changes to the state where it is pressed against the braking force application position 13B of the friction brake plate 12. Figure 3 (B) state B5).

[0046] The attraction / release detection unit 23 confirms the excitation state of the electromagnet 16 and completes the release action of the attraction plate 13. Figure 3 Step ST14 of (A) Figure 3 (B) State B1). Thereafter, the braking force is maintained by the spring force of the pressing spring 15. In this state, the braking force acts on the friction brake plate 12, maintaining the rotating shaft 120 in a stopped state. Claims (as amended under Article 19 of the Treaty) 1. (Delete) 2. (Modified) A non-excitation working brake, characterized in that, The non-excitation working brake has the following features: A friction brake plate is mounted on the rotating shaft of the object to which the braking force is applied and rotates integrally with the rotating shaft; An attraction plate, which is movable between a braking force application position pressed against the friction brake plate and a braking force release position away from the friction brake plate, and is made of a magnetic material; The pressing spring generates a holding spring force that holds the attraction plate in the position where the braking force is applied; A permanent magnet that generates a holding magnetic force to keep the attraction plate in the braking release position; An electromagnet capable of generating an electromagnetic force to move the attraction plate; and A braking control circuit drives and controls the electromagnet in such a way that, when the power is cut off, the attraction plate held in the braking force release position moves toward the braking force application position, and when the power is turned on, the attraction plate held in the braking force application position moves toward the braking force release position. The braking control circuit includes: The power monitoring unit monitors the power supply; The charging unit stores the power used to excite the electromagnet; The coil voltage control unit, when the power monitoring unit detects that the power supply has been cut off, instantaneously energizes the coil of the electromagnet in the direction of counteracting the holding magnetic force of the permanent magnet by using the power supplied from the charging unit in order to move the attraction plate from the braking force release position toward the braking force application position; and The attraction / release detection unit detects the attraction and release actions of the attraction plate. 3. The non-excitation working brake according to claim 2, characterized in that, When the power monitoring unit detects that the power has been turned on, in order to charge the charging unit and move the attraction plate from the braking force application position to the braking force release position, the coil voltage control unit instantaneously energizes the coil of the electromagnet to generate an electromagnetic force for attracting the attraction plate. 4. The non-excitation working brake according to claim 3, characterized in that, When the attraction plate is held in the position where the braking force is released, the coil voltage control unit continuously energizes the coil of the electromagnet with a voltage lower than that at the moment of instantaneous energization to generate a holding electromagnetic force that holds the attraction plate in the position where the braking force is released.

Claims

1. A non-excitation working brake, characterized in that, The non-excitation working brake has the following features: A friction brake plate is mounted on the rotating shaft of the object to which the braking force is applied and rotates integrally with the rotating shaft; An attraction plate, which is movable between a braking force application position pressed against the friction brake plate and a braking force release position away from the friction brake plate, and is made of a magnetic material; The pressing spring generates a holding spring force that holds the attraction plate in the position where the braking force is applied; A permanent magnet that generates a holding magnetic force to keep the attraction plate in the braking release position; An electromagnet that can generate an electromagnetic force to move the attraction plate. as well as A braking control circuit drives and controls the electromagnet in such a way that when the power is cut off, the attraction plate held in the braking force release position moves toward the braking force application position, and when the power is turned on, the attraction plate held in the braking force application position moves toward the braking force release position.

2. The non-excitation working brake according to claim 1, characterized in that, The braking control circuit includes: The power monitoring unit monitors the power supply; The charging unit stores the power used to excite the electromagnet; When the power monitoring unit detects that the power supply has been cut off, the coil voltage control unit instantaneously energizes the coil of the electromagnet in the direction of counteracting the holding magnetic force of the permanent magnet by using the power supplied from the charging unit in order to move the attraction plate from the braking force release position toward the braking force application position. as well as The attraction / release detection unit detects the attraction and release actions of the attraction plate.

3. The non-excitation working brake according to claim 2, characterized in that, When the power monitoring unit detects that the power has been turned on, in order to charge the charging unit and move the attraction plate from the braking force application position to the braking force release position, the coil voltage control unit instantaneously energizes the coil of the electromagnet to generate an electromagnetic force for attracting the attraction plate.

4. The non-excitation working brake according to claim 3, characterized in that, When the attraction plate is held in the position where the braking force is released, the coil voltage control unit continuously energizes the coil of the electromagnet with a voltage lower than that at the moment of instantaneous energization to generate a holding electromagnetic force that holds the attraction plate in the position where the braking force is released.

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