JP2025042839A - Non-excitation type electromagnetic brake - Google Patents

Abstract

To provide a non-excitation operation type electromagnetic brake which enables a brake state to be manually released in an easy manner and operates braking at a degree that the brake can be operated by human power after the brake is released.SOLUTION: A non-excitation operation type electromagnetic brake 10 is used for a motor for assisting behaviour of a human or providing care and includes: a braked member which rotates around a rotation axis L with the motor; brake members 12, 13 provided so as to be movable along the rotation axis L; an elastic member 5 which presses the brake members 12, 13 against the braked member; an electromagnet 6 which separates the brake members 12, 13 from the braked member during energization; a housing which houses the elastic member 5 and the electromagnet 6; and an operation part 9 which can extend a length of a housing part S which houses the elastic member 6 of the housing.SELECTED DRAWING: Figure 4

Description

The present invention relates to a non-excitation type electromagnetic brake.

There is known a non-excitation actuated electromagnetic brake that operates in an emergency and can be released manually. For example, Patent Document 1 discloses a non-excitation actuated electromagnetic brake that can be released by operating a manual release lever.

JP 2002-054664 A

When an electromagnetic brake is used in a care device or auxiliary device that assists human movements, it is required that the person wearing the device or a person nearby can easily manually release the brake after the brake is activated in an emergency. Furthermore, when manually released, it is preferable that the brake torque is not completely set to zero, but that a certain degree of brake torque is applied when the device is manually released so that the device can be moved to a safe state. More specifically, it is preferable that a brake torque is applied that is sufficient to move the device with human force.

However, with the electromagnetic brake described in Patent Document 1, it is necessary to operate the manual release lever against the elastic force of the elastic member inside the electromagnetic brake, making it difficult to manually release the brake state easily. In addition, since the brake torque becomes zero when the brake is manually released, it is difficult to transition the device to a safe state.

The present invention aims to provide a non-excitation actuated electromagnetic brake that can be easily released manually and that provides braking that can be operated by human force after the brake is released.

A non-excitation actuated electromagnetic brake according to one aspect of this embodiment includes:
A non-excitation type electromagnetic brake used in a motor for assisting human movements or for nursing care,
A braked member that rotates about a rotation axis together with the motor;
A braking member provided so as to be movable along the rotation axis;
an elastic member that presses the braking member against the braked member;
an electromagnet that separates the braking member from the braked member when energized;
a housing that accommodates the elastic member and the electromagnet;
an operation unit capable of extending a length of an accommodation portion of the housing that accommodates the elastic member,
By operating the operating portion after the electromagnetic brake is activated, the elastic force of the elastic member is reduced so that the braked member and the braking member can be slid by human force.

According to the present invention, even if the brakes are activated in an emergency, the person wearing the device or people nearby can easily manually release the brakes. In addition, after the brakes are released, the device can be moved to a safe state by applying the brakes to a level that allows the device to be moved by human force.

FIG. 1 is a conceptual diagram of a motor-driven nursing care device equipped with a non-excitation type electromagnetic brake. FIG. 2 is an explanatory diagram of a brake non-operation state of the non-excitation operation type electromagnetic brake according to the embodiment of the present invention. FIG. 2 is an explanatory diagram of a brake actuation state of the non-excitation actuation type electromagnetic brake according to the embodiment of the present invention. 1 is an explanatory diagram of a manual brake release structure for a non-excitation actuation type electromagnetic brake according to an embodiment of the present invention. FIG. 4 is a graph showing the magnitude of brake torque versus the rotation angle of an operation unit of a non-excitation actuated electromagnetic brake according to an embodiment of the present invention.

The present embodiment will be described below with reference to the drawings. For the sake of convenience, the description of components having the same reference numbers as components already described in the description of the embodiment will be omitted. Also, for the sake of convenience, the dimensions of each component shown in the drawings may differ from the actual dimensions of each component.

1 is a conceptual diagram of a motor-driven nursing care device equipped with a non-excitation type electromagnetic brake. The motor-driven nursing care device 100 is a nursing care robot that supports waking up by holding a person requiring care H with a motor-driven arm 100A. When the nursing care device 100 is holding the person requiring care H, if a failure of the built-in battery B of the nursing care device 100 or the like causes the non-excitation type electromagnetic brake 10 mounted on the motor M that drives the arm 100A to operate, the person requiring care H may become unable to move while being held by the nursing care device 100. For this reason, the inventor has considered a brake configuration that allows people around the person requiring care H to easily manually release the brake state.
<Brake operation structure of non-excitation type electromagnetic brake>

The brake actuation structure of the non-excitation actuation type electromagnetic brake according to an embodiment of the present invention will be explained using Figures 2 and 3.

Figure 2 is an explanatory diagram of a non-excitation actuated electromagnetic brake according to an embodiment of the present invention in a brake non-actuated state. Figure 3 is an explanatory diagram of a non-excitation actuated electromagnetic brake according to an embodiment of the present invention in a brake actuated state. As shown in Figures 2 and 3, the non-excitation actuated electromagnetic brake 10 includes a rotating shaft portion 2 that rotates around a rotation axis L, a hub 3, a friction member 4 (hereinafter, the hub 3 and the friction member 4 are also collectively referred to as the braked member), and a housing 1.

The rotating shaft 2 is connected to the output shaft of a motor M (not shown) and is rotated around a rotation axis L by the motor M. The rotating shaft 2 is rotatably supported by a bearing (not shown) relative to the housing 1.

The hub 3 is attached to the outer periphery of the rotating shaft portion 2. The hub 3 has a cylindrical main body portion 3M and a flange portion 3F that extends from the main body portion 3M to the outer periphery. For example, a spline groove or key groove is provided on the inner periphery surface of the main body portion 3M and the outer periphery surface of the rotating shaft portion 2, so that the rotating shaft portion 2 and the hub 3 cannot rotate relative to each other. Alternatively, the hub 3 may simply be press-fitted into the rotating shaft portion 2, making them unable to rotate relative to each other.

The friction member 4 is a flat ring-shaped member through whose center the rotating shaft portion 2 and the hub 3 are inserted. The friction member 4 has a plate-shaped portion 41 and a pair of friction portions 42. The friction portions 42 are brake shoes and are members having a high coefficient of friction. The pair of friction portions 42 are attached to one side and the other side of the plate-shaped portion 41 in the direction of the rotation axis L.

The housing 1 includes an outer plate 12, an inner plate 13 (hereinafter, the outer plate 12 and the inner plate 13 are collectively referred to as the braking members), and a yoke 14, and accommodates multiple sets (e.g., four sets) of elastic members 5, electromagnets 6, and operating parts 9. The friction member 4 is located between the outer plate 12 and the inner plate 13 in the direction of the rotation axis L. The inner plate 13 is displaceable in the direction of the rotation axis L relative to the yoke 14.

The elastic member 5 is, for example, a coil spring, and exerts an elastic restoring force in a direction to move the inner plate 13 away from the yoke 14. The electromagnet 6 is fixed to the yoke 14, and when energized, an electromagnetic force is generated in a direction to attract the inner plate 13 toward the yoke 14. In the brake non-operation state shown in FIG. 2, the electromagnet 6 is energized, and the inner plate 13 is attracted toward the yoke 14 against the elastic restoring force of the elastic member 5. Therefore, the friction member 4 is not in contact with the inner plate 13 and the outer plate 12, and no brake torque is generated. In contrast, in the brake operation state shown in FIG. 3, the electromagnet 6 is not energized, and the inner plate 13 moves in a direction to move away from the yoke 14 due to the elastic restoring force of the elastic member 5. Therefore, the friction portion 42 of the friction member 4 is sandwiched between the outer plate 12 and the inner plate 13, and a brake torque is generated.
<Manual release structure of non-excitation type electromagnetic brake>

Using Figures 4 and 5, we will explain the manual brake release structure of a non-excitation actuated electromagnetic brake according to an embodiment of the present invention.

Figure 4 is an explanatory diagram of the manual brake release structure of a non-excitation actuation type electromagnetic brake according to an embodiment of the present invention. For the sake of explanation, the vertical direction of the paper in Figure 4 is the direction of the rotation axis L.

The non-excitation actuated electromagnetic brake 10 shown in FIG. 4 is in a brake actuated state, with no current passing through the electromagnet 6. The elastic restoring force of the elastic member 5 causes the friction portion 42 of the friction member 4 to be sandwiched between the outer plate 12 and the inner plate 13, generating a brake torque.

As shown in FIG. 4, the yoke 14 has a window W for operating the operating unit 9. The operating units 9 are provided at positions facing the windows W along the outer periphery of the housing 1. The operating units 9 also have a hexagonal recess 9a in the center. The operating unit 9 is configured to rotate in the A direction (a direction different from the direction in which the elastic force of the elastic member 4 acts) shown in FIG. 4 by manually rotating the hexagonal recess 9a from the outside of the yoke 14 through the window W using a hexagonal wrench or the like. The operating unit 9 also has an elliptical shape with different major and minor axes in a cross section along the outer periphery of the housing 1, and when rotated in the A direction by rotation, the height H of the operating unit 9 in the direction of the rotation axis L becomes lower. The hexagonal recess 9a is not limited to a hexagon.

The operating unit 9 is disposed at a position facing the inner plate 13 in the direction of the rotation axis L via the elastic member 5, and at a position in contact with the elastic member 5 in a cross section perpendicular to the direction of the rotation axis L. Therefore, when the operating unit 9 rotates in the A direction by a rotation operation, the height H of the operating unit 9 in the direction of the rotation axis L decreases, and the elastic member 5 extends toward the operating unit 9 by the amount of the change in height H, thereby reducing the elastic restoring force. In other words, the operating unit 9 has the function of extending the length of the storage section S that stores the elastic member 5.

This reduces the brake torque, allowing the braked member and the braking member to slide by human force. In other words, the brake actuation state of the non-excitation actuation type electromagnetic brake 10 can be manually released.

The operating unit 9 is not limited to an egg-shaped shape, and may have any shape (e.g., a rectangular parallelepiped shape) in which the height H in the direction of the rotation axis L changes by manual operation. The operating unit 9 is also not limited to a configuration that allows rotational operation, and may be configured to allow operation in a direction intersecting the direction in which the elastic restoring force of the elastic member 5 acts. For example, the operating unit 9 may have a stepped shape with different heights H, and may be configured such that the height H decreases and the elastic member 5 extends toward the operating unit 9 by operating in a direction intersecting the direction in which the elastic restoring force of the elastic member 5 acts, thereby reducing the brake torque. In this case, the operating unit 9 is capable of changing the length of the storage section S that stores the elastic member 5 in multiple stages.

FIG. 5 is a graph showing the magnitude of the brake torque versus the rotation angle of the operating part of the non-excitation actuation type electromagnetic brake according to the embodiment of the present invention. The horizontal axis shows the rotation angle θ of the operating part 9 in the A direction (see FIG. 4), and the vertical axis shows the magnitude of the brake torque T. As shown in FIG. 5, as the rotation angle θ increases, the brake torque T decreases. Specifically, assuming that the contraction length of the elastic member 5 from its natural length at a rotation angle θ of 0° (state before the operating part 9 is rotated) is x, and the magnitude of the brake torque T is _T0 , when the operating part 9 is rotated from the rotation angle θ of 0° to 90°, the rate of change in the contraction length x of the elastic member 5 (the ratio of the length of the elastic member 5 extended relative to the contraction length x) is 25% and the amount of change in the magnitude of the brake torque T is ΔT, ΔT is about 25% of _T0 . In other words, the magnitude of the brake torque T can be reduced by about 25%. In this way, it is possible to change the braking force after manual release of the non-excitation actuation type electromagnetic brake 10.

As described above, the non-excitation actuated electromagnetic brake 10 of this embodiment is provided with a manual brake release structure that allows the braked state to be easily released manually, thereby allowing the braked member and the braking member to slide together by human force.
Therefore, even if a non-excitation actuated electromagnetic brake used in a motor for assisting human movement or for nursing care is actuated in an emergency, the person wearing the device or people nearby can easily manually release the brake. Also, after the brake is released, the device can be moved to a safe state by applying the brake to a level that allows the device to be moved by human force.

Although the embodiment of the present invention has been described above, it goes without saying that the technical scope of the present invention should not be interpreted as being limited by the description of this embodiment. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications of the embodiment are possible within the scope of the invention described in the claims. The technical scope of the present invention should be determined based on the scope of the invention described in the claims and its equivalents. For example, in the above embodiment, a configuration was shown in which the friction member 4 rotates together with the rotating shaft portion 2 of the motor, but a configuration in which the friction member 4 is provided on the outer plate 12 and the inner plate 13 may also be used.

1: Housing 2: Rotating shaft portion 3: Hub 3M: Main body portion
3F: Flange portion 4: Friction member 5: Elastic member 6: Electromagnet 9: Operation portion 9a: Hexagonal recess 10: Non-excitation type electromagnetic brake
12: Outer plate 13: Inner plate 14: Yoke 41: Plate-shaped portion 42: Friction portion 100: Nursing device 100A: Arm S: Storage portion W: Window

Claims (6)

A non-excitation type electromagnetic brake used in a motor for assisting human movements or for nursing care,
A braked member that rotates about a rotation axis together with the motor;
A braking member provided so as to be movable along the rotation axis;
an elastic member that presses the braking member against the braked member;
an electromagnet that separates the braking member from the braked member when energized;
a housing that accommodates the elastic member and the electromagnet;
an operation unit capable of extending a length of an accommodation portion of the housing that accommodates the elastic member,
A non-excitation operated electromagnetic brake in which, by operating the operating unit after the electromagnetic brake is activated, the elastic force of the elastic member is reduced so that the braked member and the braking member can be slid by human force. The non-excitation actuated electromagnetic brake according to claim 1, wherein the operating part can be rotated in a direction different from the direction in which the elastic force of the elastic member acts. The non-excitation actuated electromagnetic brake according to claim 1, wherein the operating section is capable of changing the length of the storage section in two stages. The non-excitation actuated electromagnetic brake according to claim 1, wherein the operating unit can be operated by human force. The non-excitation actuated electromagnetic brake according to claim 1, wherein the operating portion is provided in a plurality of portions along the outer periphery of the housing. The operating portion is composed of a rectangular recess that fits into a rectangular protrusion, and is a non-excitation actuated electromagnetic brake as described in claim 1.

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