Non-excitation brake

Abstract

The present invention provides a non-excitation-operated brake that can stably generate the necessary braking or holding force, while maintaining a large inner diameter and achieving a smaller diameter and thinner profile. [Solution] The non-excitation brake 1 of the present invention comprises a coil 5, an armature 6 supported so as to be movable in the axial direction of the coil 5, a field core 2 in which the coil 5 is housed and which generates an attractive force on the armature 6 when the coil 5 is excited, a disc 7 which is rotatably supported and connected to an external rotating shaft and which contacts the armature 6 when the coil 5 is de-excited, and a biasing member 4 which biases the armature 6 toward the disc 7. The biasing member 4 is a diaphragm spring 4 provided between the field core 2 and the armature 6, and the diaphragm spring 4 has an annular ring portion 4A and a plurality of claw portions 4B which are arranged in a parallel manner in the circumferential direction via a slit 4C and extend radially from the ring portion 4A at a predetermined angle.

Description

Technical Field

[0006] ,

[0001] The present invention relates to a non-excitation operating brake.

Background Art

[0002] Conventionally, brake devices for braking or holding rotating members have been used in power transmission mechanisms of various industrial devices. As an example, in the fields of robots, office automation equipment, etc., a so-called "non-excitation operating brake" is known, which has a mechanism that generates an electromagnetic attractive force by a coil and performs braking or holding in a state where the coil is de-energized (see Patent Document 1: Japanese Patent Laid-Open No. 2001-065606).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Recently, the miniaturization of equipment to be mounted has advanced, and the reduction of the diameter and thickness of non-excitation operating brakes has been demanded. However, in conventional non-excitation operating brakes such as those disclosed in Patent Document 1, a configuration in which a coil spring is used as a biasing member that generates a braking or holding force (frictional force) is common, and there is a problem that it is difficult to reduce the diameter and thickness due to factors such as the need to secure the installation space of the coil spring.

[0005] On the other hand, in a non-excitation operating brake, if the diameter and thickness are simply reduced, the attractive force becomes small and there is also a problem of securing the installation space, making it difficult to use a biasing member with a strong biasing force. As a result, there is a problem that the necessary braking or holding force (frictional force) cannot be generated.

[0006] Furthermore, when using coil springs as biasing members, the ends are treated at the beginning and end of the winding (cutting to form a contact surface, changing the pitch by bending, etc.), which can cause slight differences in biasing force depending on the circumferential position (individual differences may also occur when multiple springs are used). As a result, there was a problem in that the braking or holding force (frictional force) in unexcited brakes was unstable.

[0007] Furthermore, when attempting to reduce the diameter of the non-excitation brake, there was a problem in that the inner diameter portion (hollow portion) located in the radial center could not be made relatively large (large in diameter). [Means for solving the problem]

[0008] The present invention has been made in view of the above circumstances, and aims to provide a non-excitation-operated brake that can stably generate the necessary braking or holding force, and can be made smaller in diameter and thinner while ensuring a relatively large inner diameter.

[0009] As one embodiment, the above problem is solved by the solution disclosed below.

[0010] The disclosed non-excitation-operated brake comprises a coil on which energizing wires are wound around a spool, an armature supported to be movable along the axial direction of the coil, a field core housing the coil and generating an attractive force on the armature when the coil is excited, a disc rotatably supported and connected to an external rotating shaft, and which contacts the armature when the coil is de-excitation, and a biasing member that biases the armature toward the disc, wherein the biasing member is a diaphragm spring provided between the field core and the armature, and the diaphragm spring has an annular ring portion and the ring portion For the surface of the board At a predetermined angle From the ring portion in an inclined state A shape that extends in the radial direction. , a shape cut in the radial direction Multiple circumferential directions via slits Individuals at equal intervals Having parallel claw portions The configuration is such that it is fixed to the field core using screws or rivets. This is a requirement.

[0011] Furthermore, it is preferable that the diaphragm spring has a configuration in which the claw portion extends toward the center of the ring portion.

[0012] As another example, it is preferable that the diaphragm spring has a configuration in which the claw portion extends away from the center of the ring portion.

[0013] Furthermore, it is preferable that the field core has stepped portions formed to have different axial dimensions, and that the diaphragm spring is fixed to the stepped portion with the ring portion fitted into the portion of the stepped portion that has a shorter axial dimension.

[0014] Furthermore, it is preferable that the diaphragm spring is configured such that the ring portion is fixed to the stepped portion by crimping.

[0015] Another example is that the diaphragm spring is preferably configured such that the ring portion is fixed to the stepped portion by welding.

[0016] Another example is that the diaphragm spring is preferably fixed using screws or rivets with the ring portion fitted to the stepped portion. [Effects of the Invention]

[0017] According to the disclosed non-excitation-operated brake, the necessary braking or holding force can be stably generated, and the diameter can be reduced and the thickness reduced while ensuring a relatively large inner diameter. [Brief explanation of the drawing]

[0018] [Figure 1] A perspective view showing an example of a non-excitation operated brake according to an embodiment of the present invention. [Figure 2] Figure 1 is an exploded perspective view showing an example of a non-excitation-operated brake. [Figure 3] It is a cross-sectional view showing an example of an unexcited operation brake of FIG. 1. [Figure 4] It is an enlarged view of part IV in FIG. 3. [Figure 5] It is a perspective view showing another example of the unexcited operation brake according to an embodiment of the present invention. [Figure 6] It is an exploded perspective view showing an example of the unexcited operation brake of FIG. 5. [Figure 7] It is a cross-sectional view showing an example of the unexcited operation brake of FIG. 5. [Figure 8] It is an enlarged view of part VIII in FIG. 7.

Mode for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view (schematic view) showing an example of an unexcited operation brake 1 according to an embodiment of the present invention, FIG. 2 is an exploded perspective view (schematic view) thereof, FIG. 3 is a cross-sectional view (schematic view) thereof, and FIG. 4 is an enlarged view of part IV in FIG. 3. Further, FIG. 5 is a perspective view (schematic view) showing another example of the unexcited operation brake 1 according to an embodiment of the present invention, FIG. 6 is an exploded perspective view (schematic view) thereof, FIG. 7 is a cross-sectional view (schematic view) thereof, and FIG. 8 is an enlarged view of part VIII in FIG. 7. In the following, the direction parallel to the common central axis C of the constituent members shown in the drawings may be referred to as the "axial direction" for explanation. Also, in all the drawings for explaining the embodiments, members having the same function are denoted by the same reference numerals, and the repeated description thereof may be omitted.

[0020] The unexcited operation brake 1 according to the present embodiment is, for example, a device incorporated in a robot, OA equipment, etc., and performs braking or holding of a rotating member (specific example: a rotating shaft) in a power transmission mechanism. More specifically, it is configured with a coil that generates an electromagnetic attractive force, and is of a so-called "unexcited operation" type that performs braking or holding in a state where the coil is unexcited.

[0021] The non-excitation-operated brake 1 according to this embodiment comprises a coil 5 around which a power supply line 5B is wound on a spool 5A, and an armature 6 supported so as to be movable along the axial direction of the coil 5 (a direction parallel to the central axis C of the spool 5A). It also includes a field core 2 that houses the coil 5 and generates an attractive force on the armature 6 when the coil 5 is energized (when the power supply line 5B is energized).

[0022] Furthermore, the de-excitation brake 1 is rotatably supported and connected to an external rotating shaft (not shown) (details will be described later), and includes a disc 7 (provided with a base plate 7A and lining 7B, described later) that contacts the armature 6 when the coil 5 is de-excited (a state in which the power supply line 5B is not supplied and the device is de-excited). In addition, it includes a biasing member 4 that biases the armature 6 toward the disc 7.

[0023] Furthermore, the de-excitation brake 1 includes a friction plate 9 that houses and seals the above-mentioned components between itself and the field core 2. In this embodiment, the disc 7 (lining 7B) is also in contact with the friction plate 9 when the coil 5 is de-excitationed (details will be described later).

[0024] Next, each component will be described in detail. First, the field core 2 is a double cylindrical structure with a roughly cup-shaped opening at one end (the side with the friction plate 9 that engages with it), specifically comprising an inner cylinder portion 2a and an outer cylinder portion 2b, and a bottom surface portion 2c connecting the inner cylinder portion 2a and the outer cylinder portion 2b at the other end, so that the cross-sectional (half-cross-sectional) shape is formed in a U-shape. The annular space between the inner cylinder portion 2a and the outer cylinder portion 2b becomes a housing portion 2d that accommodates the coil 5, etc. With this configuration, when the annular coil 5 housed in the housing portion 2d is energized (i.e., energized in the current-carrying wire 5B), the field core 2 becomes magnetic and exerts an attractive force on the armature 6. As an example, the field core 2 is formed using a magnetic metal material such as S10C. In this embodiment, the inner cylinder portion 2a, the outer cylinder portion 2b, and the bottom surface portion 2c are formed as a single unit, but they may also be formed separately and connected (not shown).

[0025] Furthermore, the field core 2 is provided with a stepped portion 2e that is formed to have different axial dimensions (i.e., defined by a longer axial portion 2f and a shorter portion 2g). The biasing member 4 is fixed to this stepped portion 2e (details will be described later).

[0026] Next, the coil 5 has a configuration in which a conductive wire 5B is wound around a spool 5A. Specifically, the spool 5A is made of an electrically insulating resin material and is formed in a U-shape with a cross-sectional (half-cross-sectional) shape having flange-like portions extending radially at both ends of the cylindrical portion. The coil 5 is constructed by winding a conductive wire 5B made of a metallic conductive material (for example, copper) around the outer circumferential surface of the cylindrical portion of the spool 5A. With this configuration, when the coil 5 is energized (energized by energizing the conductive wire 5B), a magnetic force is generated, and the surrounding field core 2 acts as an electromagnet, generating an attractive force towards the armature 6. As a result, the armature 6 moves in a direction toward the field core 2 against the biasing force of the biasing member 4 (described later). On the other hand, when the coil 5 is de-energized (unenergized because the conductive wire 5B is not energized), the magnetic force disappears, and the surrounding field core 2 does not act as an electromagnet, so the attractive force towards the armature 6 disappears. As a result, the biasing force of the biasing member 4 causes the armature 6 to move away from the field core 2.

[0027] Next, the armature 6 has several screws 11 (three, for example) for fixing the friction plate 9 to the field core 2, which are inserted through a collar 13 attached to a notch 6a at the periphery. This makes the armature 6 movable only in the axial direction. Therefore, when an attractive force is generated on the field core 2 by the excitation of the coil 5, the armature 6 moves towards the field core 2 against the aforementioned biasing force and is attracted to the end faces (one-end faces) 2e of the inner cylinder 2a and outer cylinder 2b. On the other hand, when the attractive force on the field core 2 disappears due to the de-excitation of the coil 5, the armature 6 moves away from the field core 2 due to the aforementioned biasing force and is attracted to the disk 7 described later (i.e., the braking or holding action described later). As an example, the armature 6 is formed using a magnetic metal material.

[0028] Next, the disc 7 has a configuration in which a lining 7B is attached to the surface of a disc-shaped base plate 7A. In this embodiment, the lining 7B is attached to both sides of the base plate 7A, the armature 6 side and the friction plate 9 side, and braking or holding force (frictional force) is obtained by each lining 7B, resulting in a "double-plate" configuration. However, it is not limited to this configuration, and a "single-plate" configuration in which the lining 7B is attached only to the armature 6 side may also be used (not shown). Note that by adopting a "double-plate" configuration as in this embodiment, a larger braking or holding force (frictional force) can be obtained compared to a "single-plate" configuration. As an example, the base plate 7A is formed using a non-magnetic metal material such as stainless steel. The lining 7B is formed using a friction material mainly composed of resin or metal.

[0029] In this configuration, when the coil 5 is de-energized and the field core 2 does not act as an electromagnet, the attractive force of the field core 2 on the armature 6 disappears, and the biasing force of the biasing member 4 causes the armature 6 to move away from the field core 2. At this time, one surface of the armature 6 (the surface on the friction plate 9 side) and one surface of the lining 7B of the disk 7 (the surface on the field core 2 side) come into contact. Furthermore, since this embodiment is a "double-plate type," the contact (pushing) by the armature 6 causes the other surface of the lining 7B of the disk 7 (the surface on the friction plate 9 side) to come into contact with one surface of the friction plate 9 (the surface on the field core 2 side).

[0030] In this embodiment, an external rotating shaft (not shown) is connected (inserted) to the shape of the through hole 7a (a rectangular shape with rounded corners) formed in the radial center of the disk 7 (base plate 7A). At this time, the disk 7 (base plate 7A) and the rotating shaft are not completely fixed, and the disk 7 is in a state in which it can move in the axial direction. Therefore, when the rotating shaft, i.e., the disk 7, is in a rotating state, if the coil 5 is in an unexcited state (the field core 2 does not act as an electromagnet), a braking or holding force (frictional force) is generated by the above-mentioned contact (contact on both sides of the lining 7B in this embodiment), and a braking effect (i.e., an effect that slows down or stops the rotation of the disk 7 and, consequently, the rotating shaft) can be obtained. On the other hand, when the coil 5 is in an excited state (the field core 2 acts as an electromagnet), an attractive force is generated on the armature 6 by the field core 2, and the armature 6 moves in a direction toward the field core 2 against the biasing force of the biasing member 4. In this case, since the above-mentioned contact does not occur, no braking effect is obtained.

[0031] Next, the friction plate 9 is plate-shaped and annular (with a through hole in the center), and is configured to house and seal the above-mentioned components between itself and the field core 2. Furthermore, in this embodiment, as described above, when the coil 5 is in an unexcited state, the inner surface of the friction plate 9 (the surface on the field core 2 side) comes into contact with the surface of the lining 7B of the opposing disk 7 (the surface on the friction plate 9 side), generating a braking or holding force (frictional force). As an example, the friction plate 9 is formed using the same metal material as the armature 6.

[0032] Next, the configuration of the biasing member 4, which is characteristic of this embodiment, will be described in detail. Specifically, a diaphragm spring 4 is provided between the field core 2 and the armature 6 as the biasing member 4.

[0033] Here, the diaphragm spring 4 is formed using a thin (for example, plate thickness of about 0.2 mm to 1.0 mm) plate material of a metal material (for example, stainless steel, spring steel, etc.). Specifically, it has an annular ring portion 4A and claw portions 4B that extend radially from the ring portion 4A at a predetermined angle (i.e., inclined at a predetermined angle with respect to the plate surface 4a of the ring portion 4A). Multiple claw portions 4B are arranged at equal intervals along the circumferential direction of the ring portion 4A via slits 4C. With this configuration, when the claw portions 4B are pushed (compressed in the direction that reduces the predetermined angle, i.e., the inclination), a restoring force (elastic force) is generated that causes the claw portions 4B to return to their original shape, and this can be used as a biasing force. The number and shape of the claw portions 4B are appropriately set according to conditions such as the attractive force generated in the field core 2 and the movement dimension (distance) of the armature 6.

[0034] The configuration incorporating the diaphragm spring 4 makes it possible to solve the problems of the conventional non-excitation brakes described above. Specifically, in conventional non-excitation brakes, a coil spring is generally used as the biasing member that generates braking or holding force (frictional force), and there was a problem in that it was difficult to reduce the diameter and thickness due to factors such as the need to secure space for the installation of the coil spring. In this embodiment, a configuration was devised in which a diaphragm spring is used as the biasing member 4 instead of a coil spring, making it possible to reduce the overall diameter and thickness. Furthermore, if the diameter and thickness are simply reduced, the suction force will decrease and there will be a problem in securing installation space, making it difficult to use a biasing member with a strong biasing force, and thus it will be impossible to generate the necessary braking or holding force (frictional force). In this embodiment, it was confirmed by simulation that the necessary braking or holding force can be sufficiently obtained. Thus, in the non-excitation brake 1, it is possible to reduce the diameter and thickness to a degree that was difficult to achieve with conventional methods when trying to obtain the necessary braking or holding force.

[0035] As a specific example, as shown in Figure 2, the diaphragm spring 4 has a configuration in which the claw portion 4B extends toward the center of the ring portion 4A (the position of the central axis C). With this configuration, since the claw portion 4B is positioned inward (radially inward) of the ring portion 4A, the outer diameter of the diaphragm spring 4 can be reduced in particular. In other words, this is an advantageous configuration for reducing the diameter of the unexcited brake 1.

[0036] Alternatively, as shown in Figure 6, the diaphragm spring 4 has a configuration in which the claw portion 4B extends away from the center of the ring portion 4A (the position of the central axis C). With this configuration, since the claw portion 4B is positioned outside (radially outward) of the ring portion 4A, the inner diameter of the diaphragm spring 4 can be increased. In other words, this configuration is advantageous for making the inner diameter portion (hollow portion) 1a provided at the radial center of the unexcited brake 1 larger (larger in diameter).

[0037] Furthermore, in this embodiment, the diaphragm spring 4 is fixed in a state in which the ring portion 4A is fitted to the portion 2g of the stepped portion 2e of the field core 2 that has a short axial dimension. This configuration makes it possible to further reduce the thickness of the non-excitation operated brake 1.

[0038] As a specific example, as shown in Figures 7 and 8, the diaphragm spring 4 has a configuration in which the ring portion 4A is fixed to the stepped portion 2e by crimping. With this configuration, compared to fixing by welding (spot welding) or fixing by screws (or rivets), it is possible to fix the ring portion 4A in a state in which deformation does not occur (or hardly occurs) along the circumferential direction (i.e., in the case of welding, deformation due to welding distortion may occur, and in the case of screws (rivets), deformation due to tightening may occur). Therefore, in the diaphragm spring 4, the biasing force, which is the same (or nearly the same) as the design value, can be uniformly generated over the entire circumferential region. In other words, the braking or holding force (frictional force) in the non-excitation-operated brake 1 can be stably generated. However, it is not limited to crimping, and a configuration in which it is fixed by welding can also be adopted. In that case, it is an advantageous configuration in that it can maintain a fixed state that does not loosen over a long period of time.

[0039] Alternatively, as shown in Figures 3 and 4, the diaphragm spring 4 is configured such that the ring portion 4A is fitted onto the stepped portion 2e and fixed using a screw (or rivet) 15. This configuration allows the diaphragm spring 4 (ring portion 4A) to be detachably fixed to the field core 2. Therefore, when wear occurs on the claw portion 4B, the diaphragm spring 4 can be replaced with a new one. In other words, this configuration is advantageous in that it enables the creation of an unexcited brake 1 that can be used for the longest possible period, assuming maintenance (parts replacement).

[0040] As described above, the present invention makes it possible to realize a non-excitation-operated brake that can stably generate the necessary braking or holding force, and that can be made smaller in diameter and thinner while ensuring a relatively large inner diameter.

[0041] It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the scope of the present invention. [Explanation of symbols]

[0042] 1. Non-excitation brake 2 Field Cores 4. Biasing member (diaphragm spring) 5 coils 6 Armature 7 discs 9 Friction Plate

Claims

1. A coil with a live wire wound around a spool, An armature supported so as to be movable along the axial direction of the coil, A field core that houses the coil and generates an attractive force on the armature when the coil is energized, A disk that is rotatably supported and connected to an external rotating shaft, and which contacts the armature when the coil is de-energized, The armature comprises a biasing member that biases the armature toward the disk side, As the biasing member, a diaphragm spring is provided between the field core and the armature. The diaphragm spring has an annular ring portion and multiple claw portions arranged at equal intervals in the circumferential direction via slits that are inclined at a predetermined angle with respect to the plate surface of the ring portion. The claw portions are arranged radially from the ring portion at a predetermined angle with respect to the plate surface of the ring portion and are cut radially. The diaphragm spring is fixed to the field core using screws or rivets. A non-excitation-operated brake characterized by the following features.

2. The circumferential length at the tip of the claw portion is configured to be longer than the circumferential length at the same radial position as the tip portion in the adjacent slit. The non-excitation-operated brake according to claim 1, characterized by the above.

3. The diaphragm spring is fixed to the field core by having one screw or rivet positioned for each of the three claws in the circumferential direction of the ring portion. A non-excitation-operated brake according to claim 1 or claim 2, characterized by the above.

4. The diaphragm spring is configured such that the claw portion extends toward the center of the ring portion. A non-excitation-operated brake according to claim 1 or claim 2, characterized by the above.

5. The diaphragm spring is configured such that the claw portion extends away from the center of the ring portion. A non-excitation-operated brake according to claim 1 or claim 2, characterized by the above.

6. The field core has stepped portions formed to have different axial dimensions, The diaphragm spring is configured such that the ring portion is fitted into the portion of the stepped portion that has a shorter axial dimension and is fixed to the stepped portion. A non-excitation-operated brake according to claim 1 or claim 2, characterized by the above.

7. The diaphragm spring is configured such that the ring portion is fixed to the stepped portion by crimping. The non-excitation-operated brake according to claim 6, characterized by the above.

8. The diaphragm spring is configured such that the ring portion is fixed to the stepped portion by welding. The non-excitation-operated brake according to claim 6, characterized by the above.

Images