Electromagnetic brake device

Abstract

To provide an electromagnetic brake device capable of reducing generation of instantaneous braking force even when electric power supply to the electromagnetic brake device is shut off during traveling for any reason.SOLUTION: An electromagnetic brake device 16 includes: a brake stator; a rotating shaft; a brake disk; a brake armature 42; an adsorption mechanism for adsorbing the armature to the brake stator; a first energizing member for energizing the brake armature 42 in a direction separating from the brake stator; and regulation members for regulating rotation of the brake armature 42. Notches 63 to which the regulation members are inserted are provided in the brake armature 42. The notch includes a groove enabling displacement in the circumferential direction of the rotating shaft of the brake armature 42 relative to the regulation member. The electromagnetic brake device includes second energizing members each coupling the regulation member to the brake armature 42 and applying energizing force for hindering the displacement in the circumferential direction of the brake armature 42 to the brake armature 42.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] This invention relates to an electromagnetic brake device.

Background Art

[0002] As a conventional technology related to an electromagnetic brake device, for example, an electromagnetic brake disclosed in Patent Document 1 is known. The electromagnetic brake disclosed in Patent Document 1 is mounted on a golf cart and is a non-excitation operation type that stops the rear wheels of the golf cart when parking or making an emergency stop.

[0003] This electromagnetic brake is provided at the axial end of a rotating shaft that rotates together with the rear wheels and is supported by a transmission case. The electromagnetic brake has a yoke, an excitation coil installed inside the yoke, an armature, and a side plate. The yoke is fixed to the transmission case by fixing bolts, and the side plate located at the outer end of the brake is attached by attachment bolts. The armature is positioned between the magnetic adsorption surface of the yoke and the side plate and is mounted in a state of being movable in the axial direction with respect to the attachment bolts and having its rotation restricted with respect to the yoke. Further, the yoke is equipped with a braking spring composed of a compression coil spring that biases the armature toward the side plate.

[0004] These yoke, armature, and side plate are each formed to be annular, and the rotating shaft is inserted through the axial center of each. This rotating shaft is rotatably supported by a bearing in the transmission case, and a brake disk is mounted on a boss fixed to the axial end portion so as to be movable in the axial direction by spline fitting.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the electromagnetic brake disclosed in Patent Document 1, if the power supply to the electromagnetic brake is interrupted for some reason during the running of the vehicle, the electromagnetic brake will operate, generating an instantaneous braking force, and the operator will experience a very sudden deceleration feeling.

[0007] The present invention has been made in view of the above problems, and an object of the present invention is to provide an electromagnetic brake device that can mitigate the generation of an instantaneous braking force even if the power supply to the electromagnetic brake device is interrupted for some reason during running.

Means for Solving the Problems

[0008] In order to solve the above problems, the present invention includes a brake stator, a rotating shaft rotatable with respect to the brake stator, a brake plate fixed to the rotating shaft, a brake armature interposed between the brake stator and the brake plate, an adsorption mechanism that adsorbs the brake armature to the brake stator by energization, a first biasing member that biases the brake armature in a direction to separate it from the brake stator, and a regulating member provided on the brake stator that regulates the rotation of the brake armature. In the electromagnetic brake device in which the brake armature is provided with a notch into which the regulating member is inserted, the notch has a groove that allows displacement of the brake armature in the circumferential direction of the rotating shaft with respect to the regulating member, and has a second biasing member that connects the regulating member and the brake armature and applies a biasing force to the brake armature that prevents circumferential displacement of the brake armature. The second biasing member is a tension coil spring. It is characterized by this.

[0009] In the present invention, the brake armature is provided with a notch into which a regulating member is inserted, and the notch has a groove that allows the brake armature to be displaced in the circumferential direction of the rotation axis with respect to the regulating member. A second biasing member that connects the regulating member and the brake armature applies a biasing force to the brake armature that prevents displacement in the circumferential direction of the brake armature. For this reason, even if the power supply to the electromagnetic brake device is interrupted for some reason during travel, the brake armature displaces in the circumferential direction by an amount corresponding to the groove against the biasing force. As a result, the generation of an instantaneous braking force is alleviated, and the sudden deceleration feeling experienced by the operator can be reduced. Also, since the second biasing member is a tension coil spring, if the rotational force attempting to displace the brake armature in the circumferential direction is equal to or less than the initial tension of the tension coil spring, the tension coil spring will not extend and the brake armature will not displace. Therefore, since the electromagnetic brake device is immediately braked, the braking position of the vehicle can be accurately set. Further, when the rotational force attempting to displace the brake armature in the circumferential direction exceeds the initial tension of the tension coil spring, the brake armature will displace and extend the tension coil spring, and the generation of instantaneous braking force will be alleviated.

[0010] Also, The present invention includes a brake stator, a rotating shaft rotatable relative to the brake stator, a brake plate fixed to the rotating shaft, a brake armature interposed between the brake stator and the brake plate, an attracting mechanism that attracts the brake armature to the brake stator by energization, a first biasing member that biases the brake armature in a direction away from the brake stator, and a restricting member provided on the brake stator that restricts rotation of the brake armature. In the electromagnetic brake device in which the brake armature is provided with a notch into which the restricting member is inserted, the notch has a groove that allows displacement of the brake armature in the circumferential direction of the rotating shaft relative to the restricting member, and has a second biasing member that connects the restricting member and the brake armature and applies a biasing force to the brake armature that prevents circumferential displacement of the brake armature, and the second biasing member is a compression coil spring. In the present invention, even if the second biasing member is a compression coil spring, a biasing force that prevents circumferential displacement of the brake armature can be applied to the brake armature.

[0011] Further, in the above electromagnetic brake device, the groove may be formed at a position where the brake armature can be displaced in the rotational direction on the forward movement side of the rotation axis. In this case, when the power supply to the electromagnetic brake device is interrupted while the vehicle is moving forward, the brake armature displaces in the circumferential direction by an amount corresponding to the groove against the biasing force. As a result, the generation of an instantaneous braking force during forward movement can be alleviated.

[0012] Further, in the above electromagnetic brake device, the groove may be formed at a position where the brake armature can be displaced in the rotational direction on the reverse movement side of the rotation axis. In this case, when the power supply to the electromagnetic brake device is interrupted while the vehicle is moving backward, the brake armature displaces in the circumferential direction by an amount corresponding to the groove against the biasing force. As a result, the generation of an instantaneous braking force during backward movement can be alleviated.

Advantages of the Invention

[0014] According to the present invention, an electromagnetic brake device capable of alleviating the generation of an instantaneous braking force can be provided even if the power supply to the electromagnetic brake device is interrupted for some reason during travel.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0016] (First Embodiment) Hereinafter, the electromagnetic brake device according to the first embodiment will be described with reference to the drawings. The electromagnetic brake device of the present embodiment is a non-excitation braking type electromagnetic brake device that becomes a braking state in a non-excited state. Further, the electromagnetic brake device of the present embodiment is an electromagnetic brake device provided in an electric motor for running mounted on a vehicle, and the vehicle is a forklift as an industrial vehicle.

[0017] As shown in FIG. 1, the forklift 10 of the present embodiment is an electric forklift. The vehicle body 11 of the forklift 10 is provided with a pair of left and right front wheels 12 as drive wheels and a pair of left and right rear wheels 13 as steering wheels. A cargo handling device 14 is provided at the front part of the vehicle body 11. The vehicle body 11 is equipped with a pair of electric motors 15, an electromagnetic brake device 16 provided in the electric motor 15, and a power transmission mechanism 17. The front wheels 12 are provided with an axle 18 to which the power from the power transmission mechanism 17 is transmitted. The rear wheels 13 are steered by a steering device (not shown). The forklift 10 of the present embodiment is a four-wheel forklift, but it may also be a three-wheel forklift with one rear wheel. The cargo handling device 14 includes a mast (not shown), a lift bracket (not shown), and attachments (not shown) necessary for cargo handling, etc.

[0018] The electric motor 15 is a driving power source for the running of the forklift 10. The electromagnetic brake device 16 is an electromagnetic brake that switches between a braking state and a non-braking state by energization. The power transmission mechanism 17 is a mechanism that decelerates the driving force of the pair of left and right electric motors 15 and transmits it to the axle 18 of the front wheels 12, and includes a speed reducer (not shown), a differential (not shown), etc.

[0019] As shown in FIG. 2, the electric motor 15 includes a rotor 22 and a stator 23. The rotor 22 has a rotor core 25 and a rotating shaft 26 that is fixed through the rotor core 25. The rotating shaft 26 protrudes from both ends of the rotor 22. The stator 23 includes a cylindrical stator core 27 and a stator coil 28. Coil ends 29 of the stator coil 28 are formed at both ends of the stator core 27. In FIG. 2, the coil end 29 at one end is not shown, and only the coil end 29 at the other end is shown.

[0020] The electric motor 15 includes an output-side bracket 31 attached to one end of the stator 23, and a brake-side bracket 32 on the side of the electromagnetic brake device 16 attached to the other end of the stator 23. The output-side bracket 31 rotatably supports one end of the rotating shaft 26 via a bearing (not shown). The brake-side bracket 32 rotatably supports the other end of the rotating shaft 26 via a bearing 33. The output-side bracket 31 and the brake-side bracket 32 are connected by a through bolt (not shown). A part of the rotating shaft 26 protrudes from the output-side bracket 31 as an output shaft 34. An electromagnetic brake device 16 is attached to the other end of the brake-side bracket 32. Details of the electromagnetic brake device 16 will be described later.

[0021] A terminal block 35 is provided on the brake-side bracket 32. A lead wire 36 is drawn out from the other coil end 29 of the stator coil 28, and the drawn lead wire 36 is drawn into the terminal block 35. The terminal block 35 is connected to the lead wire 36 and has a terminal portion (not shown) connectable to an external wiring connected to an external device (for example, an inverter). The lead wire 36 is a wiring for supplying power to the electric motor 15.

[0022] Next, the electromagnetic brake device 16 that can brake the rotation of the rotor 22 will be described. As shown in FIG. 3, the electromagnetic brake device 16 includes a brake stator 41, a fixing plate 43, a brake hub 44, a brake plate 45, and a brake armature 42.

[0023] As shown in FIG. 3, the brake stator 41 has a disk-shaped disk portion 46 and a cylindrical cover portion 47 that extends from the outer peripheral edge of the disk portion 46 toward the brake-side bracket 32. The disk portion 46 is provided with a recess 48 at the center for accommodating the other end of the rotating shaft 26 and a part of the brake hub 44. An annular electromagnetic coil 49 is built into the disk portion 46 as an adsorption mechanism. The electromagnetic coil 49 energizes the brake stator 41 when energized and de-energizes the brake stator 41 when the energization stops. The cover portion 47 covers the brake armature 42, the fixing plate 43, and the brake plate 45.

[0024] The disk portion 46 has a through hole 52 through which a bolt 53 for fixing the electromagnetic brake device 16 to the electric motor 15 is inserted. The brake-side bracket 32 is provided with a threaded hole 54 that faces the through hole 52 and allows the bolt 53 to be screwed in. The brake stator 41 is fixed to the brake-side bracket 32 by screwing the bolt 53 inserted through the through hole 52 into the threaded hole 54. The bolt 53 passes through the brake armature 42 and the fixing plate 43.

[0025] The disk portion 46 has a plurality of bottomed holes 55 located on the inner circumferential side of the electromagnetic coil 49. The plurality of bottomed holes 55 are arranged at equal intervals in the circumferential direction of the disk portion 46. A coil spring 56 as a first biasing member is built into each bottomed hole 55. The central axis of each coil spring 56 is along the axis P of the rotating shaft 26. The coil spring 56 biases the brake armature 42 axially so as to press it against the brake plate 45.

[0026] The brake armature 42 faces the brake stator 41 in the axial direction of the axis P of the rotating shaft 26. As shown in FIG. 4, the brake armature 42 is disc-shaped, but the detailed configuration of the brake armature 42 will be described later. The brake armature 42 is movable in the axial direction of the axis P of the rotating shaft 26. Further, the coil spring 56 built into the brake stator 41 has one end in the axial direction in contact with the brake stator 41, and the other end in the axial direction protruding from the brake stator 41 is in contact with the brake armature 42. The coil spring 56 biases the brake armature 42 in a direction away from the brake stator 41 along the axial direction of the rotating shaft 26.

[0027] When the brake stator 41 is excited by energizing the electromagnetic coil 49, the brake armature 42 is attracted to the brake stator 41 against the biasing force of the coil spring 56. When the electromagnetic coil 49 is not energized and the brake stator 41 is non-excited, the brake armature 42 moves in a direction away from the brake stator 41 under the biasing force of the coil spring 56.

[0028] The electromagnetic brake device 16 includes a disc-shaped fixing plate 43 fixed to the brake side bracket 32. The fixing plate 43 is located at a certain distance from the brake stator 41 along the axial direction of the rotating shaft 26. The brake stator 41 and the fixing plate 43 are arranged side by side in the axial direction of the axis P of the rotating shaft 26. The fixing plate 43 is fixed to the brake side bracket 32 by fastening a bolt (not shown) passing through the fixing plate 43 to the brake side bracket 32. The brake armature 42 is disposed between the brake stator 41 and the fixing plate 43 in the axial direction of the rotating shaft 26.

[0029] The electromagnetic brake device 16 includes a brake hub 44 that rotates integrally with the rotating shaft 26, and a brake plate 45 is integrally fixed to the brake hub 44. The brake plate 45 is disc-shaped and is disposed between the brake armature 42 and the fixed plate 43 in the axial direction P of the rotating shaft 26, and is movable in the axial direction P of the rotating shaft 26. The plate surface of the brake plate 45 is provided with a friction material 58 that contacts the brake armature 42 in the braking state and a friction material 57 that contacts the fixed plate 43 in the braking state.

[0030] In the electromagnetic brake device 16 configured as described above, when the electromagnetic coil 49 is excited, the brake armature 42 is attracted to the brake stator 41, the brake armature 42 is separated from the brake plate 45, and the pressing of the brake plate 45 against the fixed plate 43 is released. As a result, the rotating shaft 26 is released from the braking state and can rotate freely without being restricted.

[0031] On the other hand, when the electromagnetic coil 49 is not excited, the brake armature 42 is pressed toward the brake plate 45 by the biasing force of the coil spring 56, and the brake plate 45 is pressed against the fixed plate 43. Therefore, the brake plate 45 is sandwiched between the brake armature 42 and the fixed plate 43. As a result, the rotating shaft 26 is brought into a braking state by the frictional force generated between the brake armature 42 and the brake plate 45. That is, the parking brake is actuated.

[0032] Here, the brake armature 42 will be described in detail. As shown in FIG. 4, a circular hole 61 through which the rotating shaft 26 and the brake hub 44 pass is formed in the central portion of the brake armature 42. Further, a plurality of notches 63 cut from the outer peripheral edge 62 are provided near the outer periphery of the brake armature 42. The notches 63 are formed corresponding to the number of bolts 53. The rotation of the brake armature 42 is restricted by inserting the bolts 53 into the notches 63. That is, the bolt 53 corresponds to a restricting member that restricts the rotation of the brake armature 42.

[0033] The notch 63 has a groove 64 that allows displacement of the rotation axis 26 of the brake armature 42 in the rotation direction with respect to the bolt 53. The groove 64 extends toward the side corresponding to the rotation direction of the rotation axis 26 when the forklift 10 moves forward. That is, the groove 64 is a forward groove. Therefore, the brake armature 42 can be displaced in the circumferential direction by an amount corresponding to the circumferential length of the groove 64. In this embodiment, displacement of the rotation axis 26 in the rotation direction when the forklift 10 moves backward is not possible due to the restriction of the bolt 53.

[0034] The brake armature 42 has a locking portion 65 for locking one end 67 of a tension coil spring 66 as a second biasing member. The other end 68 of the tension coil spring 66 is locked to the bolt 53. The tension coil spring 66 applies a biasing force to the brake armature 42 that attempts to rotate the brake armature 42 in the direction opposite to the rotation direction in which the brake armature 42 rotates toward the groove 64, so that the brake armature 42 does not rotate toward the groove 64. That is, the tension coil spring 66 connects the bolt 53 and the brake armature 42 and applies a biasing force to the brake armature 42 that prevents circumferential displacement of the brake armature 42.

[0035] In this embodiment, the tension coil spring 66 is located radially outside the brake plate 45 and between the brake armature 42 and the fixing plate 43 so as not to interfere with the brake plate 45. Also, the tension coil spring 66 is provided corresponding to the number of bolts 53. As shown in the graph showing the relationship between the load (F) and the spring length (L) in FIG. 5, the tension coil spring 66 has an initial tension F1. Therefore, the tension coil spring 66 does not extend unless a force exceeding the initial tension F1 is applied. That is, in order for the brake armature 42 to be displaced in the rotation direction corresponding to the forward direction of the rotation axis 26, the brake armature 42 needs to receive a rotational force in the rotation direction that exceeds the initial tension F1 during braking.

[0036] Next, the operation of the electromagnetic brake device 16 according to this embodiment will be described. The case where the braking state of the electromagnetic brake device 16 is released for the forklift 10 to travel will be described. When the electromagnetic brake device 16 is in the braking state, the electromagnetic coil 49 is in a demagnetized state. For this reason, the brake armature 42 is pressed against the brake plate 45 by the biasing force of the coil spring 56. The braking force of the electromagnetic brake device 16 is generated by the brake plate 45 being clamped between the brake armature 42 and the fixed plate 43.

[0037] When releasing the braking state of the electromagnetic brake device 16, electric power is applied to the electromagnetic coil 49. The energization of the electromagnetic coil 49 is performed, for example, by releasing the parking brake when the key is turned ON. When the electromagnetic coil 49 is energized and excited, the brake armature 42 is attracted by the magnetic force and pulled toward the brake stator 41 against the biasing force of the tension coil spring 66, and separated from the brake plate 45. Then, the brake armature 42 is adsorbed to the brake stator 41. As a result, the braking state of the electromagnetic brake device 16 is released and becomes a non-braking state, and the forklift 10 can travel.

[0038] Next, the case where the electromagnetic brake device 16 is changed from the non-braking state to the braking state will be described. When the electromagnetic brake device 16 is set to the braking state, the energization to the electromagnetic coil 49 is cut off. The cut-off of the energization to the electromagnetic coil 49 is performed, for example, by operating the parking brake and turning the key OFF. When the electromagnetic coil 49 is demagnetized due to the cut-off of the energization, the brake armature 42 is separated from the brake stator 41 by the biasing force of the tension coil spring 66 and pressed against the brake plate 45. Then, the brake plate 45 is clamped by the brake armature 42 and the fixed plate 43. As a result, the non-braking state of the electromagnetic brake device 16 is released and becomes a braking state, and the forklift 10 cannot travel.

[0039] Incidentally, when the forklift 10 is moving forward, if the energization of the electromagnetic coil 49 is interrupted for some reason, the brake armature 42 is separated from the brake stator 41 by the biasing force of the tension coil spring 66 and pressed against the brake plate 45. In this embodiment, when a braking force that causes each tension coil spring 66 to extend acts, the brake armature 42 is displaced in the rotational direction corresponding to forward movement, thereby alleviating the sudden braking force and reducing the very sudden deceleration feeling experienced by the operator. Specifically, when the brake armature 42 is pressed against the brake plate 45, it is displaced in the direction corresponding to forward movement by an amount corresponding to the groove 64, and the rotating shaft 26 rotates by the amount of displacement of the brake armature 42.

[0040] Even when the vehicle speed of the forklift 10 is low and a braking force that does not cause each tension coil spring 66 to extend acts on the brake armature 42, the brake armature 42 does not displace. When each tension coil spring 66 does not extend, the rotation of the rotating shaft 26 stops instantaneously.

[0041] The electromagnetic brake device 16 of this embodiment has the following effects. (1) The brake armature 42 is provided with a notch 63 into which the bolt 53 is inserted, and the notch 63 has a groove 64 that allows displacement of the brake armature 42 in the circumferential direction of the rotating shaft 26 with respect to the bolt 53. A biasing member that connects the bolt 53 and the brake armature 42 applies a biasing force to the brake armature 42 that prevents circumferential displacement of the brake armature 42. Therefore, even if the power supply to the electromagnetic brake device 16 is interrupted for some reason during the running of the forklift 10, the brake armature 42 displaces in the circumferential direction by an amount corresponding to the gap against the biasing force. As a result, the rotating shaft 26 rotates by the amount of displacement of the brake armature 42, the generation of an instantaneous braking force is alleviated, and the sudden deceleration feeling experienced by the operator can be reduced.

[0042] (2) Since the biasing member is the tension coil spring 66, if the rotational force attempting to displace the brake armature 42 in the circumferential direction is equal to or less than the initial tension of the tension coil spring 66, the tension coil spring 66 will not extend, and the brake armature 42 will not be displaced. Therefore, since the electromagnetic brake device 16 is immediately braked, the braking position of the forklift 10 can be accurately set. Also, when the rotational force attempting to displace the brake armature 42 in the circumferential direction exceeds the initial tension of the tension coil spring 66, the brake armature 42 will be displaced to extend the tension coil spring 66, and the generation of instantaneous braking force will be alleviated.

[0043] (3) The groove 64 is formed at a position where the brake armature 42 can be displaced in the rotational direction on the forward movement side of the rotary shaft 26. For this reason, when the power supply to the electromagnetic brake device 16 is cut off during the forward movement of the forklift 10, the brake armature 42 is displaced in the circumferential direction by an amount corresponding to the groove 64 against the biasing force. As a result, the generation of instantaneous braking force during forward movement can be alleviated.

[0044] (4) The brake armature 42 is displaced to extend the tension coil spring 66, and the generation of instantaneous braking force is alleviated. For this reason, the impact during braking on the electromagnetic brake device 16 can be suppressed as compared with a brake armature not provided with a tension coil spring, and damage due to the impact during braking of the electromagnetic brake device 16 can be reduced.

[0045] (Second Embodiment) Next, the electromagnetic brake device according to the second embodiment will be described. The configuration of the brake armature of the electromagnetic brake device of this embodiment is different from that of the first embodiment. In this embodiment, for the same configurations as those in the first embodiment, the description of the first embodiment is incorporated by reference, and common reference numerals are used.

[0046] The electromagnetic brake device 71 of this embodiment has a brake armature 72 shown in FIG. 6. The notch 63 has a groove 64 that enables displacement of the rotating shaft 26 of the brake armature 72 in the rotational direction with respect to the bolt 53, and a groove 73 that enables displacement of the rotating shaft 26 of the brake armature 72 in the rotational direction with respect to the bolt 53. The groove 73 is a groove that extends toward the side corresponding to the rotational direction of the rotating shaft 26 when the forklift 10 moves backward. That is, the groove 73 is a groove for backward movement. Therefore, the brake armature 72 can be displaced in the circumferential direction by an amount corresponding to the circumferential lengths of the groove 64 and the groove 73. That is, in this embodiment, the brake armature 72 can be displaced in the rotational direction of the rotating shaft 26 not only when the forklift 10 moves forward but also when it moves backward.

[0047] The brake armature 72 has a locking portion 76 for locking one end 75 of a tension coil spring 74 as a biasing member for backward movement, in addition to the tension coil spring 66 as a biasing member for forward movement. The other end 77 of the tension coil spring 74 is locked to the bolt 53.

[0048] The electromagnetic brake device 71 of this embodiment exhibits the same effects as those of the first embodiment. Also, the groove 73 is formed at a position where the brake armature 72 can be displaced in the rotational direction on the backward movement side of the rotating shaft 26. Therefore, when the power supply to the electromagnetic brake device 71 is cut off during the backward movement of the forklift 10, the brake armature 72 is displaced in the circumferential direction by an amount corresponding to the groove 73 against the biasing force. As a result, the generation of instantaneous braking force during backward movement can be alleviated.

[0049] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the invention. For example, the following modifications may be made.

[0050] ○ In the above embodiment, the tension coil spring was used as the second biasing member that connects the restricting member and the brake armature and applies a biasing force to the brake armature to prevent circumferential displacement of the brake armature, but it is not limited to this. The biasing member may be, for example, a compression coil spring 78 as shown in FIG. 7. When the second biasing member is the compression coil spring 78, it is not necessary to lock the compression coil spring 78 to the bolt 53 serving as the restricting member. Further, the compression coil spring 78 can be accommodated in the groove 64, enabling effective utilization of the space. 。 ○ In the above embodiment, the bolt for fixing the electromagnetic brake device to the electric motor was used as the restricting member, but it is not limited to this. The restricting member may be, for example, a bolt for fixing the fixing plate to the brake stator. Further, as the restricting member other than the bolt, for example, a pin may be used. ○ In the above embodiment, tension coil springs as the second biasing member were provided for all the bolts serving as the restricting member, but it is not limited to this. For example, the second biasing member may be provided only for a specific restricting member among the plurality of restricting members. In this case, the number of parts can be reduced as compared with the case where the second biasing member is provided for all the restricting members. ○ In the above embodiment, the electromagnetic brake device provided in a forklift as an industrial vehicle was exemplified and described, but the application target of the electromagnetic brake device is not limited to forklifts. The application target of the electromagnetic brake device may be an electric vehicle such as a tractor or a towing tractor.

Explanation of Reference Numerals

[0051] 10 Forklift 11 Vehicle body 14 Cargo handling device 15 Electric motor 16, 71 Electromagnetic brake device 17 Power transmission mechanism 26 Rotating shaft 41 Brake stator 42, 72 Brake armature 43 Fixing plate 44 Brake hub 45 Brake rotor 46 Disk part 49 Electromagnetic coil (adsorption mechanism) 53 Bolt (restricting member) 56 Coil spring (first biasing member) 63 Notch 64, 73 Groove 65, 76 Locking part 66, 74 Tension coil spring (second biasing member)

Claims

1. A brake stator, a rotating shaft rotatable relative to the brake stator, a brake plate fixed to the rotating shaft, a brake armature interposed between the brake stator and the brake plate, an adsorption mechanism for adsorbing the brake armature to the brake stator by energization, a first biasing member for biasing the brake armature in a direction to separate it from the brake stator, and a regulating member provided on the brake stator for regulating the rotation of the brake armature. In the electromagnetic brake device having the brake armature provided with a notch into which the regulating member is inserted, the notch has a groove enabling displacement of the brake armature in the circumferential direction of the rotating shaft with respect to the regulating member, and a second biasing member for connecting the regulating member and the brake armature and applying a biasing force to the brake armature to prevent circumferential displacement of the brake armature. The electromagnetic brake device is characterized in that the second biasing member is a tension coil spring.

2. A brake stator, a rotating shaft rotatable relative to the brake stator, a brake plate fixed to the rotating shaft, a brake armature interposed between the brake stator and the brake plate, an adsorption mechanism for adsorbing the brake armature to the brake stator by energization, a first biasing member for biasing the brake armature in a direction to separate it from the brake stator, and a regulating member provided on the brake stator for regulating the rotation of the brake armature. In the electromagnetic brake device having the brake armature provided with a notch into which the regulating member is inserted, the notch has a groove enabling displacement of the brake armature in the circumferential direction of the rotating shaft with respect to the regulating member, and a second biasing member for connecting the regulating member and the brake armature and applying a biasing force to the brake armature to prevent circumferential displacement of the brake armature. The electromagnetic brake device is characterized in that the second biasing member is a compression coil spring.

3. The electromagnetic brake device according to claim 1 or 2, wherein the groove is formed at a position where the brake armature can be displaced in the rotational direction on the forward side of the rotating shaft.

4. ​ ​ ​ ​ The electromagnetic brake device according to claim 1 or 2, characterized in that the groove is formed at a position where the brake armature can be displaced in the rotational direction on the retracted side of the rotating shaft.

Images