CN114426236B - Emergency stop device and elevator - Google Patents

Abstract

The invention provides an emergency stop device and an elevator capable of easily positioning an electromagnetic core in a standby state and a recovery state. The emergency stop device comprises a braking mechanism, a driving mechanism and a working mechanism (11). The operating mechanism (11) includes a connecting member (41), movable cores (44A, 44B), electromagnetic cores (43A, 43B), moving mechanisms (46, 47, 48) supporting the electromagnetic cores (43A, 43B) so as to be movable in directions approaching and separating from the movable cores (44A, 44B), and a positioning member (55). When the operating mechanism (11) is returned from the braking state to the standby state, the positioning member (55) abuts against the electromagnetic cores (43A, 43B) to restrict the movement of the electromagnetic cores (43A, 43B) and perform positioning of the electromagnetic cores (43A, 43B) and the movable cores (44A, 44B).

Description

Emergency stop device and elevator

Technical Field

The present invention relates to an emergency stop device for stopping a car in an emergency and an elevator having the same.

Background

Typically, rope elevators have main ropes and compensating ropes connecting a car and a counterweight, and a long object such as a governor rope for detecting the speed of the car or the counterweight. In addition, an emergency stop device is provided as a safety device in an elevator, and when the speed of the elevator car up and down along the guide rail exceeds a predetermined value, the operation of the elevator car is automatically stopped.

In recent years, an emergency stop device has been proposed in which a brake mechanism of the emergency stop device is electrically operated without using a speed limiter. As a conventional emergency stop device of this kind, there is a technique described in patent document 1, for example. Patent document 1 describes a technique in which a wedge-shaped friction member is provided, which is separated from contact with a rail by a drive spring and an electromagnet device, and a restoring motor is provided, which restores the electromagnet device to its original position while accumulating the force in the drive spring.

Patent document 1 describes that: the restoring motor drives a restoring member for pushing the electromagnet arrangement and restoring it to the holding position, the restoring member allowing the electromagnet arrangement in the holding position to move to the release position. Patent document 1 describes that: the drive spring and the restoring spring accumulate force together under the action of the restoring motor, the restoring motor rotates under the action of the restoring spring, and the restoring member is biased to the standby position.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2009-227353

Disclosure of Invention

Technical problem to be solved by the invention

However, in the technique described in patent document 1, when the electromagnet device indicating the electromagnet core is returned from the release position to the holding position, the positioning of the electromagnet device becomes complicated.

An object of the present invention is to provide an emergency stop device and an elevator capable of easily positioning an electromagnetic core in a standby state and at the time of recovery, in consideration of the above-described problems.

Technical means for solving the technical problems

In order to solve the above problems, the emergency stop device includes a braking mechanism, a driving mechanism, and an operating mechanism. The brake mechanism is provided on the lifting body, and stops the movement of the lifting body by sandwiching a guide rail for sliding the lifting body. The driving mechanism is connected to the braking mechanism and operates the driving mechanism. The brake mechanism is connected to the drive mechanism and operates the drive mechanism. The working mechanism comprises: a connecting member connected to the driving mechanism and movable together with the driving mechanism; a movable iron core fixed to the connection member; an electromagnetic core detachably adsorbing the movable iron core; a moving mechanism; and a positioning member. The moving mechanism supports the electromagnetic core so as to be movable in a direction approaching and separating from the movable iron core. When the operating mechanism is returned from the braking state to the standby state, the positioning member abuts against the electromagnetic core to restrict movement of the electromagnetic core, and positions the electromagnetic core and the movable iron core.

An elevator is an elevator provided with a lifting body which moves up and down in a hoistway,

comprising the following steps: a guide rail vertically provided in the hoistway and supporting the lifting body so as to be slidable; and an emergency stop device for stopping the movement of the lifting body based on the state of the lifting movement of the lifting body. The emergency stop device described above is used as the emergency stop device.

Effects of the invention

According to the emergency stop device and the elevator having the above-described structure, the electromagnetic core can be easily positioned in the standby state and at the time of recovery.

Drawings

Fig. 1 is a schematic configuration diagram showing an elevator according to embodiment 1.

Fig. 2 is a front view showing an emergency stop device according to embodiment 1.

Fig. 3 is a plan view of the operation mechanism of the emergency stop device according to embodiment 1, as viewed from above.

Fig. 4 is a front view showing an operation mechanism of the emergency stop device according to embodiment 1.

Fig. 5 is a front view showing a state in which an operation mechanism of the emergency stop device according to embodiment 1 is operated.

Fig. 6 is a plan view of the operation mechanism of the emergency stop device according to embodiment 2, as viewed from above.

Detailed Description

An emergency stop device and an elevator according to an example of the present embodiment will be described below with reference to fig. 1 to 6. In the drawings, common members are denoted by the same reference numerals.

1. Embodiment example 1

1-1 structural example of an Elevator

First, the structure of an elevator according to embodiment 1 (hereinafter referred to as "this example") will be described with reference to fig. 1.

Fig. 1 is a schematic configuration diagram showing a structural example of an elevator according to this example.

As shown in fig. 1, the elevator 1 of the present example performs a lifting operation in a hoistway 110 formed in a building structure. The elevator 1 includes a car 120 representing one example of a lifting body on which persons or goods are carried, main ropes 130, and a counterweight 140 representing another example of a lifting body. The elevator 1 includes a hoisting machine 100 and an emergency stop device 5.

The elevator 1 further comprises a control part 170 and a diverting pulley 150. The hoistway 110 is formed in a building structure, and a machine room 160 is provided at the top thereof.

The hoisting machine 100 and the sheave 150 are disposed in the machine room 160. The main rope 130 is wound around the traction sheave shown in the drawing of the traction machine 100. A diverting sheave 150 that spans the main rope 130 is provided near the hoisting machine 100.

One end of the main rope 130 is connected to an upper portion of the car 120, and the other end of the main rope 130 is connected to an upper portion of the counterweight 140. By driving the hoisting machine 100, the car 120 and the counterweight 140 are lifted and lowered in the hoistway 110. Hereinafter, the direction in which the car 120 and the counterweight 140 move up and down is referred to as the up-down direction Z.

The car 120 is slidably supported on 2 guide rails 201A, 201B via a guide device not shown. Similarly, the counterweight 140 is slidably supported on the counterweight-side guide rail 201C via a guide device not shown. The 2 guide rails 201A and 201B and the counterweight-side guide rail 201C extend in the hoistway 110 along the lifting direction Z.

An emergency stop device 5 for emergency stopping the lifting movement of the car 120 is provided on the car 120. The detailed structure of the emergency stop device 5 will be described later.

The machine room 160 is provided with a control unit 170. The control unit 170 is connected to the car 120 via a connection wiring not shown. The control unit 170 outputs a control signal to the car 120. The control unit 170 is provided in the hoistway 110, and is connected to a state detection sensor, not shown, for detecting the state of the car 120.

As information detected by the state detection sensor, there are position information of the car 120 that moves up and down in the hoistway 110, speed information of the car 120, acceleration information of the car 120, and the like. The positional information of the cars 120 is, for example, abnormal approach information detected when the interval between two vertically adjacent cars 120 is closer than a predetermined interval in a multi-car elevator in which a plurality of cars 120 move up and down in the same hoistway 110.

The speed information of the car 120 is, for example, abnormal descent speed information detected when the descent speed of the car 120 exceeds the rated speed to reach a predetermined speed. The acceleration information of the car 120 is, for example, abnormal acceleration information detected when the acceleration of the car 120 deviates from a predetermined pattern. The state detection sensor outputs the detected information to the control device.

The control unit 170 determines whether the state of the car 120 is abnormal or normal based on the information detected by the state detection sensor. When it is determined that the state of the car 120 is abnormal, the control unit 170 outputs an operation command signal to the emergency stop device 5. Thereby, the emergency stop device 5 operates based on the operation command signal from the control unit 170, and stops the car 120.

In the present example, an example in which the state detection sensor detects the position information, the velocity information, and the acceleration information is described, but is not limited thereto. For example, the position information, the velocity information, and the acceleration information may be detected by different sensors, respectively. Further, the control section 170 may select position information, velocity information, acceleration information and acquire them individually, or may acquire them by combining a plurality of pieces of information.

The control unit 170 and the car 120 are not limited to examples of wired connection, and may be capable of transmitting and receiving signals through wireless connection.

Hereinafter, the direction in which the car 120 moves up and down is referred to as the up-down direction Z, and the direction orthogonal to the up-down direction Z and facing the car 120 and the guide rail 201A is referred to as the first direction X. The direction orthogonal to the first direction X and also orthogonal to the lifting direction Z is set as the second direction Y.

1-2 construction of an Emergency stop device

Next, a detailed structure of the emergency stop device 5 will be described with reference to fig. 2 to 6.

Fig. 2 is a front view showing the emergency stop device 5.

As shown in fig. 2, the emergency stop device 5 includes 2 brake mechanisms 10A and 10B, an operating mechanism 11, a driving mechanism 12 for operating the brake mechanisms 10A and 10B, a first upper link 13, and a second upper link 14. The operating mechanism 11 is disposed on an upper beam 121 provided at an upper portion of the car 120.

[ drive mechanism ]

The drive mechanism 12 has a drive shaft 15, a first link member 16, a second link member 17, a first working shaft 18, a second working shaft 19, and a drive spring 20.

The first and second operating shafts 18 and 19 are provided on an upper beam 121 provided at an upper portion of the car 120. The first working shaft 18 is provided at one end of the upper beam 121 in the first direction X, and the second working shaft 19 is provided at the other end of the upper beam 121 in the first direction X. The first link member 16 is rotatably supported on the first working shaft 18, and the second link member 17 is rotatably supported on the second working shaft 19.

The first link member 16 and the second link member 17 are formed in a substantially T-shape. The first link member 16 has a working piece 16a and a connecting piece 16b. The working piece 16a protrudes substantially perpendicularly from the connecting piece 16b. Further, the working piece 16a is connected to the connecting piece 16b at a position on the one end side than the intermediate portion in the longitudinal direction. The working piece 16a protrudes toward a guide rail 201A disposed on the negative side (left side in the drawing) in the first direction X of the car 120, in which the left side of the paper surface and the lower side of the paper surface on the XYZ axes in the drawing are negative sides, and the right side of the paper surface on the XYZ axes and the upper side of the paper surface are positive sides. The first upper tie rod 13 is connected to the end of the working piece 16a on the opposite side of the connecting piece 16b by a connecting portion 26.

The first link member 16 is rotatably supported by the first working shaft 18 at a portion where the working piece 16a and the connecting piece 16b are connected. The drive shaft 15 is connected to one end portion of the connecting piece 16b in the longitudinal direction through the connecting portion 25. A connecting member 41 (see fig. 3) of the working mechanism 11, which will be described later, is connected to an end portion of the connecting piece 16b opposite to an end portion connected to the drive shaft 15, that is, to the other end portion in the longitudinal direction.

The first link member 16 is disposed such that one end portion in the longitudinal direction of the connecting piece 16b faces upward in the lifting direction Z, and the other end portion in the longitudinal direction of the connecting piece 16b faces downward in the lifting direction Z.

The second link member 17 has a working piece 17a and a connecting piece 17b. The working piece 17a protrudes substantially perpendicularly from the connecting piece 17b. Further, the work piece 17a is connected to a middle portion in the long-side direction of the connection piece 17b. The working piece 17a protrudes toward the guide rail 201B provided on the positive side of the first direction X of the car 120. The second upper tie rod 14 is connected to the end of the working piece 17a on the opposite side of the connecting piece 17b by a connecting portion 28.

The drive shaft 15 is connected to the other end portion of the connecting piece 17b in the longitudinal direction through a connecting portion 27. The second link member 17 is rotatably supported by the second working shaft 19 at the connection portion between the working piece 17a and the connecting piece 17b. The second link member 17 is disposed such that one end portion in the longitudinal direction of the connecting piece 17b faces upward in the lifting direction Z and the other end portion in the longitudinal direction of the connecting piece 17b faces downward in the lifting direction Z.

One end portion of the drive shaft 15 in the first direction X is connected to the connecting piece 16b of the first link member 16, and the other end portion of the drive shaft 15 in the first direction X is connected to the connecting piece 17b of the second link member 17. Further, the drive spring 20 is provided at an intermediate portion in the axial direction of the drive shaft 15.

The drive spring 20 is constituted by, for example, a compression coil spring. One end of the drive spring 20 is fixed to the upper beam 121 by a fixing portion 21, and the other end of the drive spring 20 is fixed to the drive shaft 15 by a pressing member 22. The drive spring 20 biases the drive shaft 15 to the positive side in the first direction X by the pressing member 22.

When the operating mechanism 11 is operated, the drive shaft 15 is biased by the drive spring 20 to move in the positive side in the first direction X. Thereby, the first link member 16 rotates about the first working shaft 18, and the end of the working piece 16a to which the first upper link 13 is connected is directed upward in the lifting direction Z. The second link member 17 rotates about the second operating shaft 19 so that the end of the operating piece 17a to which the second upper link 14 is connected is directed upward in the lifting direction Z. As a result, the first upper link 13 and the second upper link 14 are pulled upward in the lifting direction Z in a linked manner.

The first brake mechanism 10A is connected to an end of the first upper link 138 on the opposite side of the end to which the working piece 16a is connected. The second brake mechanism 10B is connected to an end of the second upper tie rod 14 on the opposite side from the end to which the working piece 17a is connected. The first upper link 13 pulls up a pair of stoppers 31, 31 (see fig. 4) of the first brake mechanism 10A described later in the upward and downward direction Z. The second upper link 14 pulls up a pair of stoppers 31 and 31 of a second brake mechanism 10B described later upward in the lifting direction Z.

[ brake mechanism ]

The first brake mechanism 10A and the second brake mechanism 10B are provided at the lower end portion of the car 120 in the lifting direction Z. The first brake mechanism 10A is provided opposite to the guide rail 201A at one end of the car 120 in the first direction X. The second brake mechanism 10B is provided opposite to the guide rail 201B at the other end portion of the car 120 in the first direction X.

The first brake mechanism 10A and the second brake mechanism 10B have the same structure, respectively. The first brake mechanism 10A and the second brake mechanism 10B have brake pieces 31, 31 (see fig. 4) capable of sandwiching the guide rails 201A, 201B. The brake 31, 31 is connected to the first upper tie rod 13 or the second upper tie rod 14. By the driving of the driving mechanism 12, the stoppers 31, 31 are pulled up in the lifting direction Z by the first and second upper links 13, 14, thereby sandwiching the rails 201A, 201B. Thereby, the lifting movement of the car 120 is braked.

[ working mechanism ]

Next, the working mechanism 11 is described with reference to fig. 3 to 6.

Fig. 3 shows a top view of the working mechanism 11 from above, fig. 4 shows a front view of the working mechanism 11, and fig. 3 and 4 show a standby state of the working mechanism 11.

As shown in fig. 3 and 4, the operating mechanism 11 includes a connection member 41, first and second electromagnetic cores 43A and 43B, first and second movable cores 44A and 44B, a base plate 45, and a drive motor 46. Further, the working mechanism 11 includes a feed screw shaft 47, a feed nut 48, and a core plate 49. The operating mechanism 11 operates the driving mechanism 12.

The substrate 45 is formed of a flat plate-like member. The base plate 45 is fixed to the upper beam 121. The portion of the fixed base 45 is not limited to the upper beam 121, and is not particularly limited as long as it is a lift car 120 as a lifting body. The fixing bracket 53, the first shaft supporting portion 54, the second shaft supporting portion 55, the auxiliary holding portion 56, and the core guide 57 are fixed on the upper surface portion 45a above the lifting direction Z of the substrate 45.

The fixing bracket 53 is disposed at the other end portion of the substrate 45 in the first direction X. The first shaft support portion 54 is disposed at one end portion of the substrate 45 in the first direction X, and the second shaft support portion 55 is disposed at the other end portion of the substrate 45 in the first direction X. The first shaft support 54 is disposed closer to the other end portion in the first direction X than the fixing bracket 53. The detailed structures of the auxiliary holding portion 56 and the core guide 57 will be described later.

The second shaft support 55, which represents a positioning member, is disposed at a standby position of the feed nut 48 and the electromagnetic cores 43A and 43B, which represent movable members, which will be described later. When the operating mechanism 11 is in the standby state and returns from the braking state to the recovery state, the electromagnetic cores 43A and 43B are brought into contact with the second shaft support portion 55 via the feed nut 48.

A drive motor 46 showing an example of the moving mechanism is fixed to the fixed bracket 53. The rotation shaft 46a of the drive motor 46 protrudes from the fixing bracket 53 toward one end in the first direction X. The feed screw shaft 47 is mounted on the rotation shaft 46a of the drive motor 46 through a coupling 51.

The feed screw shaft 47 protrudes from the drive motor 46 toward one end in the first direction X. One axial end of the feed screw shaft 47 is rotatably supported by the first shaft supporting portion 54, and the other axial end of the feed screw shaft 47 is rotatably supported by the second shaft supporting portion 55. The axial direction of the feed screw shaft 47 is arranged parallel to the first direction X. Further, a trapezoidal thread is formed on the outer peripheral surface of the feed screw shaft 47. A feed nut 48, which will be described later, is screw-engaged with the feed screw shaft 47.

Further, a retaining member 71 is provided at the other end portion in the axial direction of the feed screw shaft 47. The drop prevention member 71 is provided between the other end portion of the feed screw shaft 47 and the coupling 51. The retaining member 71 faces the one surface 55a on the other end side in the first direction X of the second shaft support 55. The escape prevention member 71 rotates together with the feed screw shaft 47, thereby preventing the feed screw shaft 47 from escaping from the second shaft support 55.

The friction reducing member 72 is provided between the escape preventing member 71 at the other end portion of the feed screw shaft 47 and the second shaft supporting portion 55. The friction reducing member 72 is fixed to one face 55a of the second shaft supporting portion 55. As the friction reducing member 72, for example, a thrust bearing is used. The friction reducing member 72 supports the escape preventing member 71 so as to be rotatable about the axial center of the feed screw shaft 47 even in a state of being sandwiched between the escape preventing member 71 and the second shaft supporting portion 55.

The driving of the driving motor 46 is controlled by the control unit 170. When the drive motor 46 rotates in the forward direction (forward rotation), a core plate 49 described later moves toward one end in the first direction X, that is, toward the negative side in the first direction X. When the drive motor 46 is rotated (reversed) in the reverse direction, the core plate 49 is moved toward the other end in the first direction X, that is, toward the positive side in the first direction X.

Next, the connecting member 41 will be described.

The connecting member 41 has a pair of armature brackets 61, an anti-rotation bracket 62, and a rod bracket 63. The armature bracket 61 is formed in a substantially L shape. The first movable iron core 44A and the second movable iron core 44B are fixed to the armature bracket 61 by the fixing member 68, wherein the second movable iron core 44B is fixed to the fixing face portion 61a of the second armature bracket 61B by the fixing member 68.

The armature bracket 61 is rotatably supported by the rod bracket 63 through a connecting pin 67. One end of the lever bracket 63 is connected to the armature bracket 61. The other end of the lever bracket 63 protrudes upward in the lifting direction Z. The lever bracket 63 is fixed to the anti-rotation bracket 62 by a fixing bolt 66.

The anti-rotation bracket 62 is formed by overlapping two members. An insertion portion 62a is formed in the anti-rotation bracket 62, and the connection piece 16b of the first link member 16 is inserted into the insertion portion 62 a. The insertion portion 62a is opened in a substantially rectangular shape corresponding to the shape of the connecting piece 16 b. The connection member 41 is connected to the first link member 16 by inserting the connection piece 16b into the insertion portion 62a and fixing by the fixing bolt 66. Further, by inserting the connection piece 16b into the insertion portion 62a, the lever bracket 63 is prevented from rotating about the fixing bolt 66.

Next, the first movable iron core 44A and the second movable iron core 44B will be described.

The first movable core 44A and the second movable core 44B are formed in a substantially disk shape. The movable cores 44A and 44B are supported by the connecting member 41, and the opposing surface 44c faces the other end side in the first direction X. Further, the first movable iron core 44A and the second movable iron core 44B are supported by the connecting member 41 with a space therebetween in the second direction Y. The length of the interval between the first movable iron core 44A and the second movable iron core 44B is set longer than the diameter of the feed screw shaft 47.

In this example, the movable cores 44A and 44B are formed in a substantially disk shape, but the present invention is not limited thereto, and the movable cores 44A and 44B may be formed in various other shapes such as a rectangular shape and an elliptical shape.

Further, the opposing surface 44c of the first movable core 44A opposes the first electromagnet core 43A, and the opposing surface 44c of the second movable core 44B opposes the second electromagnet core 43B. In the standby state shown in fig. 4 to 6, the first movable iron core 44A is attracted by the first electromagnet core 43A, and the second movable iron core 44B is attracted by the second electromagnet core 43B.

Coils are provided in the first electromagnetic core 43A and the second electromagnetic core 43B, respectively. When power is supplied to the coil from a power source not shown and the coil is energized, the first electromagnetic core 43A, the second electromagnetic core 43B, and the coil constitute an electromagnet. One of the electromagnetic cores 43A, 43B, which faces the facing surface 44c of the movable core 44A, 44B, becomes an adsorption surface 43c for adsorbing the movable core 44A, 44B.

Further, the first electromagnetic core 43A and the second electromagnetic core 43B are fixed to the core plate 49 at intervals in the second direction Y. The core plate 49 is fixed to the other surface of the first and second electromagnetic cores 43A, 43B on the opposite side of the adsorption surface 43c opposite to the movable cores 44A, 44B.

The core plate 49 is formed in a substantially flat plate shape. The first electromagnet core 43A is fixed to one end side of the core plate 49 in the second direction Y, and the second electromagnet core 43B is fixed to the other end side of the core plate 49 in the second direction Y.

The core plate 49 has a through hole 49a. The through hole 49a is formed in an intermediate portion of the core plate 49 in the second direction Y between the portions where the first electromagnetic core 43A and the second electromagnetic core 43B are fixed. The through hole 49a penetrates the core plate 49 from one end portion to the other end portion of the core plate 49 along the first direction X. The feed screw shaft 47 is inserted into the through hole 49a.

A feed nut 48, which represents an example of a screw joint, is fixed to a surface of the core plate 49 opposite to the surface to which the electromagnetic cores 43A and 43B are fixed. Thus, the electromagnetic cores 43A, 43B, the movable cores 44A, 44B, the feed nut 48, and the core plate 49 constitute a movable member.

A screw hole that is screwed to the screw portion of the feed screw shaft 47 is formed in the feed nut 48. The screw hole of the feed nut 48 communicates with the through hole 49a of the core plate 49.

When the feed screw shaft 47 rotates, the rotational force of the feed screw shaft 47 is converted into a force in the first direction X through the screw portion and the screw hole. Thus, the feed nut 48 moves in the first direction X. Further, the core plate 49 to which the feed nut 48 is fixed, the first electromagnet core 43A and the second electromagnet core 43B fixed to the core plate 49 are also moved in the first direction X.

The drive motor 46, the feed screw shaft 47, and the feed nut 48 constitute a moving mechanism for moving the electromagnetic cores 43A, 43B in a direction (first direction X in this example) approaching and separating from the movable cores 44A, 44B.

Next, the auxiliary holding portion 56 and the core guide 57 will be described.

The auxiliary holding portion 56 and the core guide 57 are provided between the first shaft supporting portion 54 and the second shaft supporting portion 55. The auxiliary holding portion 56 and the core guide 57 are disposed below the feed screw shaft 47 in the lifting direction Z.

In the standby state shown in fig. 4, the auxiliary holding portion 56 is disposed below the feed nut 48 and the core plate 49 in the lifting direction Z. For example, a leaf spring having elasticity is used as the auxiliary holding portion 56. The auxiliary holding portion 56 abuts on the core plate 49 or the feed nut 48. Further, the auxiliary holding portion 56 urges the core plate 49 and the feed nut 48 toward the feed screw shaft 47. The auxiliary holding portion 56 biases the core plate 49 and the feed nut 48, so that the feed nut 48 can be prevented from moving due to vibration generated when the car 120 operates.

The auxiliary holding portion 56 is not limited to a leaf spring, and various elastic members such as a coil spring and rubber may be used.

The core guide 57 is disposed on one end side of the auxiliary holding portion 56 in the first direction X. The core guide 57 is formed in a substantially flat plate shape. As the core guide 57 faces one end side in the first direction X, the core guide 57 is inclined in a direction away from the upper surface portion 45a of the substrate 45. When the operating mechanism 11 performs a recovery action, the core guide 57 contacts the core plate 49. Then, the core guide 57 guides the electromagnetic cores 43A, 43B to the movable cores 44A, 44B.

The core guide 57 is not limited to a substantially flat plate-like member, and is not particularly limited as long as it has an inclined surface for guiding the core plate 49. Further, a part of the substrate 45 may be formed as the core guide 57.

The connection member 41, the electromagnetic cores 43A and 43B, the movable cores 44A and 44B, the base plate 45, the drive motor 46, the feed screw shaft 47, the feed nut 48, and the core plate 49 constituting the above-described working mechanism 11 are accommodated in a housing not shown. Accordingly, the connecting member 41, the electromagnetic cores 43A and 43A constituting the holding portion, the feed screw shaft 47 constituting the moving mechanism, and the drive motor 46 are housed in one housing, whereby the emergency stop device 5 can be prevented from becoming large. Further, by integrating the functions of the working mechanism 11 in one place, maintenance work can be easily performed.

As shown in fig. 3, the operating mechanism 11 includes a determination unit 171, a comparison unit 172, and a measurement unit 173 connected to the control unit 170. The measurement unit 173 measures the current value flowing through the drive motor 46. The measurement section 173 is connected to the comparison section 172 and outputs the measured information. The comparison unit 172 stores a threshold value set in advance, and compares the information measured by the measurement unit 173 with the threshold value. The comparison section 172 is connected to the determination section 171, and outputs the comparison result to the determination section 171.

The determination unit 171 determines the operation of the drive motor 46 based on the comparison result output from the comparison unit 172. Further, the judgment section 171 is connected to the control section 170, and outputs the judgment result to the control section 170. The control unit 170 controls the operation of the drive motor 46 based on the determination result output from the determination unit 171.

In the above embodiment, the example in which 2 electromagnetic cores and 2 movable cores are provided, but the present invention is not limited thereto, and the number of electromagnetic cores and movable cores may be one or three or more.

As described above, the drive spring 20 is disposed at a position different from the operating mechanism 11, and the drive spring 20 and the operating mechanism 11 are connected by the first link member 16 as a link mechanism. Thereby, the working mechanism 11 can be miniaturized.

[ Standby State ]

First, the standby state of the emergency stop device 5 will be described with reference to fig. 3 and 4.

As shown in fig. 3 and 4, in the standby state of the emergency stop device 5, the core plate 49 and the electromagnetic cores 43A, 43B are arranged on the other end side of the feed screw shaft 47 in the first direction X. The coils of the electromagnetic cores 43A and 43B are energized, and the electromagnetic cores 43A and 43B are excited. Thus, the electromagnet is constituted by the electromagnetic cores 43A, 43B and the coil.

The movable cores 44A, 44B are attracted to the attracting surfaces 43c of the electromagnetic cores 43A, 43B. Therefore, the connecting member 41 to which the movable cores 44A and 44B are fixed holds one end portion of the connecting piece 16B of the first link member 16 toward the positive side in the first direction X. As a result, the drive shaft 15 connected to the other end portion of the connecting piece 16b is biased to the negative side in the first direction X against the biasing force of the drive spring 20.

At this time, the feed nut 48 abuts on the second shaft support 55. As described above, the second shaft support portion 55 is provided at the standby position of the movable member. Therefore, the position where the feed nut 48 abuts on the second shaft support portion 55 is set as the standby state of the emergency stop device 5. The interval between the brake 31 and the guide rail 201A, 201B of the brake mechanism 10A, 10B coupled to the movable iron cores 44A, 44B is adjusted to a desired interval.

Thereby, the electromagnetic cores 43A, 43B, the movable cores 44A, 44B, the feed nut 48, and the core plate 49 as movable members can be easily positioned. Further, the feed nut 48 abuts against the second shaft supporting portion 55, and thereby the movement of the movable member to the other end side in the first direction X, that is, the plus side is restricted. This can prevent the gap between the stopper 31 and the guide rails 201A and 201B from being shifted.

Further, since the position of the feed nut 48 can be restricted without using a switch for detecting the position of the feed nut 48, the number of components of the emergency stop device 5 can be reduced, and an operation for adjusting the position of the switch is not required.

The feed nut 48 and the feed screw shaft 47 screwed to the feed nut 48 are biased toward one end side, which is the negative side of the first direction X, by the biasing force of the drive spring 20. Therefore, the drop prevention member 71 provided on the feed screw shaft 47 is biased toward the second shaft supporting portion 55.

[ action to brake State ]

Next, an operation from the standby state to the braking state will be described with reference to fig. 5.

Fig. 5 is a front view showing a state in which the operating mechanism 11 operates.

When the control unit 170 determines that the descending speed of the car 120 exceeds a predetermined speed during the descending movement of the car 120 (see fig. 1 and 2), the control unit 170 outputs an operation command signal to the emergency stop device 5. Thereby, the energization to the electromagnetic cores 43A, 43B is cut off.

By cutting off the energization to the electromagnetic cores 43A, 43B, the magnetism of the electromagnetic cores 43A, 43B is eliminated. As a result, as shown in fig. 5, the drive shaft 15 is moved to the positive side in the first direction X by the urging force of the drive spring 20, and the one end portion of the first link member 16 is also moved to the positive side in the first direction X together with the drive shaft 15. As a result, the first link member 16 rotates about the first working shaft 18, and the second link member 17 rotates about the second working shaft 19. Thus, the driving mechanism 12 is operated by the operating mechanism 11.

Further, as shown in fig. 5, the movable cores 44A, 44B are separated from the electromagnetic cores 43A, 43B by the rotation of the first link member 16. The connecting member 41 moves to the negative side in the first direction X with the rotation of the first link member 16.

The first link member 16 and the second link member 17 rotate, and thereby the first upper link 13 and the second upper link 14 are interlocked and pulled upward in the lifting direction Z. Further, the first brake mechanism 10A connected to the first upper link 13 and the second brake mechanism 10B (refer to fig. 2) connected to the second upper link 14 are operated. As a result, the pair of stoppers 31 (see fig. 3) of the first brake mechanism 10A and the second brake mechanism 10B move upward in the lifting direction Z, and the pair of stoppers 31 of the second brake mechanism 10B coupled to the second upper link 14 sandwich the guide rails 201A, 201B, thereby mechanically stopping the lifting movement of the car 120.

Further, by separating the movable cores 44A, 44B from the electromagnetic cores 43A, 43B, the connecting member 41 can be moved without being affected by the friction force and the holding force between the feed screw shaft 47 and the feed nut 48 as the moving mechanism.

In the emergency stop device 5 of the present example, a holding portion for holding the movable cores 44A, 44B and a restoring portion for restoring the movable cores 44A, 44B from the braking state to the standby position are provided in the operating mechanism 11. Therefore, when the movable cores 44A, 44B and the connecting member 41 move, other members of the working mechanism 11 may be disturbed.

After the first link member 16 is shifted from the standby state to the braking state, the braking action of the braking mechanisms 10A, 10B is completed. Therefore, after the first link member 16 is shifted from the standby state to the braking state, the link member 41, the movable cores 44A, 44B may be brought into contact with the first shaft support portion 54, the feed screw shaft 47, and other members constituting the working mechanism 11.

[ recovery action ]

Next, a return operation of the operating mechanism 11 from the braking state to the standby state will be described.

First, the control unit 170 controls the power supply to energize the coils of the electromagnetic cores 43A and 43B. Therefore, the electromagnetic cores 43A, 43B are excited by energizing the coils. Next, the control unit 170 drives the drive motor 46 to rotate in the forward direction, thereby rotating the feed screw shaft 47.

As described above, the drop prevention member 71 provided on the feed screw shaft 47 is biased toward the second shaft support portion 55. Therefore, the feed screw shaft 47 may not smoothly rotate due to the surface pressure generated between the escape prevention member 71 and the one surface 55a of the second shaft supporting portion 55.

In contrast, in the working mechanism 11 of the present example, a friction reducing member 72 is provided between the drop preventing member 71 provided at the other end portion of the feed screw shaft 47 and the second shaft supporting portion 55, and the friction reducing member 72 supports the drop preventing member 71 so as to be rotatable. Therefore, even when the load (surface pressure) of the retaining member 71 in the negative side in the first direction X, that is, the second shaft support portion 55 side is large, the retaining member 71 and the feed screw shaft 47 can be smoothly rotated.

By the rotation of the feed screw shaft 47, the feed nut 48 screw-engaged with the feed screw shaft 47 rotates together with the feed screw shaft 47. Further, the core plate 49 is in contact with the upper surface portion 45a of the base plate 45. Thereby, the rotation of the feed nut 48 is restricted.

Further, by the rotation of the feed screw shaft 47, the rotational force of the feed screw shaft 47 is converted into a force in the first direction X by the screw portions of the feed screw shaft 47, the feed nut 48, and the screw hole. The feed nut 48 moves toward the negative side of the first direction X. The core plate 49 to which the feed nut 48 is fixed slides on the upper surface portion 45a of the base plate 45, and moves toward the negative side in the first direction X. The electromagnetic cores 43A and 43B fixed to the core plate 49 are also moved in a direction approaching the movable cores 44A and 44B, that is, in the negative side of the first direction X.

When the core plate 49 moves toward the negative side of the first direction X, the core plate 49 is in contact with the core guide 57. Further, when the core plate 49 moves toward the negative side of the first direction X, the core plate 49 rotates, and its posture is corrected by the core guide 57. Further, the directions of the electromagnet cores 43A, 43B are guided by the core guides 57 such that the adsorption surfaces 43c of the electromagnet cores 43A, 43B are opposed to the opposed surfaces 44c of the movable cores 44A, 44B.

Next, when the adsorption surface 43c of the electromagnet cores 43A, 43B is in contact with the opposing surface 44c of the movable iron cores 44A, 44B, the movable iron cores 44A, 44B are adsorbed to the adsorption surface 43c of the electromagnet cores 43A, 43B. At this time, the armature bracket 61 rotates about the connecting pin 67.

Here, when the movable iron cores 44A, 44B are brought into contact with the electromagnetic cores 43A, 43B and attracted, the movement of the feed nut 48 toward the negative side in the first direction X is restricted. Accordingly, the value of the current flowing through the drive motor 46 increases. The current value of the drive motor 46 is measured by the measuring unit 173, compared with a threshold value by the comparing unit 172, and the comparison result is judged by the judging unit 171. When the determination unit 171 determines that the current value of the drive motor 46 exceeds the threshold value, the control unit 170 determines that the movable cores 44A and 44B are in contact with the electromagnetic cores 43A and 43B.

Therefore, the contact between the movable cores 44A, 44B and the electromagnetic cores 43A, 43B can be detected without using a switch for detecting the positions of the feed nut 48, the electromagnetic cores 43A, 43B.

Next, the control unit 170 drives the drive motor 46 to rotate in the reverse direction, thereby rotating the feed screw shaft 47. Thereby, the feed nut 48 screw-engaged with the feed screw shaft 47 moves to the positive side in the first direction X. Accordingly, the core plate 49, the electromagnetic cores 43A, 43B, the movable cores 44A, 44 adsorbed by the electromagnetic cores 43A, 43B, and the connection member 41 move to the positive side in the first direction X.

By the movement of the connecting member 41 toward the positive side in the first direction X, the first link member 16 rotates against the urging force of the drive spring 20. When the feed nut 48 abuts on the second shaft supporting portion 55, the movement of the feed nut 48 and the electromagnetic cores 43A, 43B toward the positive side in the first direction X is restricted.

Thereby, the electromagnetic cores 43A, 43B, the movable cores 44A, 44B, the feed nut 48, and the core plate 49 as movable members can be easily positioned. As a result, the gap between the stopper 31 and the guide rails 201A, 201B can be prevented from being shifted when the return operation is performed, and the gap between the stopper 31 and the guide rails 201A, 201B can be maintained at a desired position.

Further, by restricting the movement of the feed nut 48 to the positive side in the first direction X, a force toward the negative side in the first direction X acts on the feed screw shaft 47 that is screw-engaged with the feed nut 48. Therefore, the escape prevention member 71 provided at the other end portion of the feed screw shaft 47 is pressed against the one surface 55a of the second shaft supporting portion 55, and the surface pressure exerted by the escape prevention member 71 on the second shaft supporting portion 55 rises.

A friction reducing member 72 is provided between the drop preventing member 71 and the second shaft supporting portion 55, the friction reducing member 72 supporting the drop preventing member 71 so as to be rotatable. Thus, even if the surface pressure of the retaining member 71 applied to the second shaft supporting portion 55 increases, the retaining member 71 and the feed screw shaft 47 can be smoothly rotated when the drive motor 46 is driven to rotate in the forward direction again.

Further, by restricting the movement of the feed nut 48 to the positive side in the first direction X, the value of the current flowing through the drive motor 46 increases. The current value of the drive motor 46 is measured by the measuring unit 173, compared with a threshold value by the comparing unit 172, and the comparison result is judged by the judging unit 171. When the determination unit 171 determines that the current value of the drive motor 46 exceeds the threshold value, the control unit 170 determines that the movable cores 44A and 44B and the electromagnetic cores 43A and 43B have moved to the standby positions shown in fig. 3 and 4. Then, the control unit 170 stops driving the driving motor 46. Thereby, the restoring operation of the working mechanism 11 is completed.

Thus, according to the emergency stop device 5 of the present example, the movable cores 44A, 44B and the electromagnetic cores 43A, 43B can be detected to return to the standby position without using a switch for detecting the positions of the feed nut 48 and the electromagnetic cores 43A, 43B.

In the emergency stop device 5 of the present example, the thrust bearing is described as an example of the friction reducing member 72, but not limited thereto, as the friction reducing member 72, a washer or the like having a solid lubrication treatment applied to the surface thereof may be applied.

Further, an example in which the friction reducing member 72 is arranged between the slip-off preventing member 71 and the second shaft supporting portion 55 is described, but is not limited thereto. At least one of the surfaces of the drop prevention member 71 and the second shaft support 55 that face each other may be subjected to a surface treatment for reducing friction. Thus, even if the surface pressure of the retaining member 71 applied to the second shaft support portion 55 increases, the retaining member 71 can be rotated relative to the second shaft support portion 55.

Further, an example in which the current value of the drive motor 46 is used as the drive information is described, but is not limited thereto. As the driving information, for example, various other information such as the driving time of the driving motor 46, the rotational torque generated on the rotation shaft 46a of the driving motor 46, and the like may be applied. The control unit 170 detects the positions of the feed nut 48 and the electromagnetic cores 43A and 43B based on the drive information, and controls the drive motor 46 as the moving mechanism

Further, a mechanical switch or an optical switch may be used to detect the positions of the feed nut 48 and the electromagnetic cores 43A, 43B, and the like. Further, detection of the attraction operation of the movable cores 44A, 44B and the electromagnetic cores 43A, 43B can be determined based on the value of the current flowing through the coils of the electromagnetic cores 43A, 43B.

In the present example, an example in which the feed nuts 48 fixed to the electromagnetic cores 43A, 43B by the core plate 49 are abutted on the second shaft support 55 as a positioning member is described, but is not limited thereto. For example, the core plate 49 may be abutted against the second shaft support portion 55, or the electromagnetic cores 43A, 43B may be abutted directly against the second shaft support portion 55. That is, the member abutted against the positioning member may be a member fixed to the electromagnet cores 43A, 43B and moving together with the electromagnet cores 43A, 43B.

2. Embodiment example 2

Next, an emergency stop device according to embodiment 2 will be described with reference to fig. 6.

Fig. 6 is a plan view of the operation mechanism of the emergency stop device according to embodiment 2, as viewed from above. The same reference numerals are given to the parts common to the emergency stop device 5 of embodiment 1, and overlapping description is omitted.

The working mechanism 11B according to embodiment 2 shown in fig. 6 includes an elastic member 73 provided between the feed nut 48 and the second shaft support 55. The elastic member 73 is, for example, a compression coil spring, and is mounted on the feed screw shaft 47. The other end portion of the elastic member 73 in the first direction X is fixed to the surface 55a of the second shaft support portion 55 on the one end side in the first direction X.

In the return operation, when the feed nut 48 moves toward the second shaft support portion 55, the feed nut 48 contacts the elastic member 73, and the elastic member 73 is elastically deformed. Therefore, the time until the movement of the feed nut 48 is restricted can be slowed down, and the rise of the current value of the drive motor 46 can be made gentle.

Further, the rise of the surface pressure applied to the second shaft support portion 55 and the friction reducing member 72 by the retaining member 71 can be made gentle. This makes it possible to set the threshold value of the current value for stopping the driving of the driving motor 46 before the surface pressure significantly increases. As a result, the drive motor 46 can be stopped in a state where the surface pressure of the retaining member 71 is low, and the retaining member 71 and the feed screw shaft 47 can be smoothly rotated when the drive motor 46 is driven again. Further, the torque required to drive the motor 46 can be reduced, and the drive motor 46 can be miniaturized.

The elastic member 73 is not limited to a compression coil spring, and various other elastic members such as a leaf spring and rubber can be used.

Other structures are the same as those of the emergency stop device 5 according to embodiment 1, and therefore, the description thereof will be omitted. The emergency stop device according to embodiment 2 can also obtain the same operational effects as those of the emergency stop device 5 according to embodiment 1 described above.

The present invention is not limited to the embodiments described above and shown in the drawings, and various modifications can be made without departing from the spirit of the invention described in the scope of the claims.

In the above embodiment example, an example in which the second shaft support portion 55 is used as the positioning member against which the feed nut 48 abuts is described, but is not limited thereto. For example, as the positioning member, a member that protrudes from the upper surface portion 45a of the substrate 45 toward the feed screw shaft 47 on the one end side in the first direction X than the second shaft support portion 55, and the feed nut 48 and the electromagnetic cores 43A and 43B are brought into contact with the member may be applied. Further, by using the second shaft support portion 55 as a positioning member, the number of components can be reduced.

Although the example in which the drive motor 46 is disposed on the second shaft support portion 55 side has been described, the present invention is not limited to this, and the drive motor 46 may be disposed on one end portion side in the first direction X than the first shaft support portion 54. In this case, the escape prevention member 71 provided on the feed screw shaft 47 is disposed between the first shaft support portion 54 and the rotation shaft 46a of the drive motor 46.

In addition, when the electromagnetic cores 43A and 43B are in contact with the movable cores 44A and 44B during the return operation, the movement of the feed nut 48 to the negative side in the first direction X is restricted. Accordingly, a force directed to the positive side in the first direction X acts on the feed screw shaft 47 and the escape prevention member 71, and the surface pressure of the escape prevention member 71 applied to the first shaft support portion 54 increases. Therefore, in order to smoothly rotate the feed screw shaft 47 and the escape prevention member 71, the friction reducing member 72 is provided between the first shaft supporting portion 54 and the escape prevention member 71.

Further, an example in which the drive motor 46, the feed screw shaft 47, and the feed nut 48 are used as the moving mechanism is described, but is not limited thereto. As the moving mechanism for moving the electromagnetic cores 43A, 43B, for example, belt driving, gear driving, chain driving, a mechanism using a linear motion solenoid, and other various moving mechanisms can be applied.

Although the example in which the direction in which the electromagnetic core of the operating mechanism 11 moves is set to be almost parallel to the first direction X has been described, it is not limited thereto. The moving direction of the electromagnet core of the working mechanism 11 may be set to be almost parallel to the lifting direction Z or the second direction Y, or may be a direction inclined with respect to the first direction X, the second direction Y, or the lifting direction Z. Further, the first link member 16 and the second link member 17 may be disposed at both end portions of the second direction Y of the car 120, and the driving shaft 15 may be disposed along the second direction Y.

The elevator is not limited to the car 120, and the counterweight 140 may be applied. The emergency stop device may be provided to the counterweight 140 to emergency stop the lifting movement of the counterweight 140. In this case, an operating mechanism, a driving mechanism, and the like, which constitute the emergency stop device, are disposed on the counterweight 140.

In the above embodiment, the control unit 170 for controlling the entire elevator 1 was described as an example of the control unit for controlling the emergency stop device, but the present invention is not limited to this. As the control unit, other various control units such as a control unit provided in the car 120 and controlling only the car 120, a control unit controlling only the emergency stop device, and the like can be applied.

The present invention can also be applied to a multi-car elevator in which a plurality of cars are moved up and down in one hoistway.

In the present specification, terms such as "parallel" and "orthogonal" are used, but these terms are not limited to "parallel" and "orthogonal" and include "parallel" and "orthogonal" as well as "substantially parallel" and "substantially orthogonal" within a range where the functions thereof can be exhibited.

Description of the reference numerals

1 elevator, 5 emergency stop device, 10A, 10B first brake mechanism, 11B working mechanism, 12 drive mechanism, 13, 14 upper tie rod, 15 drive shaft, 16 first link member, 17 second link member, 16a, 17B working piece, 16B, 17B connecting piece, 18 first working shaft, 19 second working shaft, 20 drive spring, 41 connecting member, 43A, 43B electromagnetic core, 43A suction surface, 44A, 44B movable iron core, 44A facing surface, 45 base plate, 46 drive motor, 46a rotation shaft, 47 feed screw shaft, 48 feed nut, 49 core, 53 fixing bracket, 54 first shaft support, 55 second shaft support, 71 anti-disengaging member, 72 friction reducing member, 73 elastic member, 100 traction machine, 110 hoistway, 120 car (elevator), 121 upper beam, 130 main rope, 140 counterweight (elevator), 150 counterweight (elevator), 160 machine room, 170 control part, 201A, 201B guide rail.

Claims (6)

1. An emergency stop device, comprising:

a brake mechanism that is provided on the lifting body and stops movement of the lifting body by sandwiching a guide rail for sliding of the lifting body;

a drive mechanism connected to the brake mechanism and operating the brake mechanism; and

an operating mechanism connected to the driving mechanism and operating the driving mechanism,

the working mechanism comprises:

a connecting member connected to the driving mechanism and movable together with the driving mechanism;

a movable iron core fixed to the connection member;

an electromagnetic core detachably adsorbing the movable iron core;

a moving mechanism that supports the electromagnetic core so as to be movable in a direction approaching and separating from the movable iron core; and

a positioning member that comes into contact with the electromagnetic core when the operating mechanism is in a standby state and returns from a braking state to a standby state, restricts movement of the electromagnetic core, positions the electromagnetic core and the movable iron core,

The moving mechanism has:

a driving motor;

a feed screw shaft connected to a rotation shaft of the drive motor, the feed screw shaft being rotationally driven by the drive motor; and

a feed nut disposed on the electromagnet core and threadably engaged with the feed screw shaft,

the working mechanism has a first shaft support portion for supporting the feed screw shaft so as to be rotatable, the first shaft support portion supporting one axial end portion of the feed screw shaft, and a second shaft support portion supporting the other axial end portion of the feed screw shaft,

the positioning member is the second shaft supporting portion, the movable iron core is separated from the electromagnetic core when the operating mechanism is in a braking state, and the movable iron core and the connecting member move to the first shaft supporting portion side,

when the operating mechanism is returned from the braking state to the standby state, the electromagnetic core is moved in a direction approaching the movable core by the rotation of the driving motor, and if the electromagnetic core is attracted to the movable core to restrict the movement of the electromagnetic core, the contact between the movable core and the electromagnetic core is judged by measuring the current value of the driving motor and comparing with a threshold value, and then the driving motor is rotated in a reverse direction, so that the electromagnetic core attracted to the movable core is moved in a direction toward the positioning member until the feed nut abuts on the positioning member, thereby returning to the standby state.

2. An emergency stop device according to claim 1, wherein,

has an anti-drop member provided at an end of the feed screw shaft and disposed between the drive motor and the second shaft support portion,

a friction reducing member is provided on one surface of the second shaft support portion, which surface is opposite to the anti-slip member, and supports the anti-slip member so as to be rotatable about the axial center of the feed screw shaft.

3. An emergency stop device according to claim 1, wherein,

has an anti-drop member provided at an end of the feed screw shaft and disposed between the drive motor and the second shaft support portion,

a surface treatment for reducing friction is performed on at least one of the surfaces of the slip-off preventing member and the second shaft supporting portion that face each other.

4. An emergency stop device according to claim 1, wherein,

the operating mechanism has an elastic member disposed between the electromagnet core and the positioning member.

5. An emergency stop device according to claim 1, wherein,

the electromagnetic core driving device is provided with a control part which detects the position of the electromagnetic core based on the driving information of the moving mechanism and controls the moving mechanism.

6. An elevator having a lifting body that moves up and down in a hoistway, comprising:

a guide rail vertically provided in the hoistway and supporting the lifting body so as to be slidable; and

an emergency stop device for stopping the movement of the lifting body based on the state of the lifting movement of the lifting body,

the emergency stop device is provided with:

a brake mechanism provided on the lifting body and stopping movement of the lifting body by sandwiching the guide rail;

a drive mechanism connected to the brake mechanism and operating the brake mechanism; and

an operating mechanism connected to the driving mechanism and operating the driving mechanism,

the working mechanism comprises:

a connecting member connected to the driving mechanism and movable together with the driving mechanism;

a movable iron core fixed to the connection member;

an electromagnetic core detachably adsorbing the movable iron core;

a moving mechanism that supports the electromagnetic core so as to be movable in a direction approaching and separating from the movable iron core; and

A positioning member that comes into contact with the electromagnetic core when the operating mechanism is in a standby state and returns from a braking state to a standby state, restricts movement of the electromagnetic core, positions the electromagnetic core and the movable iron core,

the moving mechanism has:

a driving motor;

a feed screw shaft connected to a rotation shaft of the drive motor, the feed screw shaft being rotationally driven by the drive motor; and

a feed nut disposed on the electromagnet core and threadably engaged with the feed screw shaft,

the working mechanism has a first shaft support portion for supporting the feed screw shaft so as to be rotatable, the first shaft support portion supporting one axial end portion of the feed screw shaft, and a second shaft support portion supporting the other axial end portion of the feed screw shaft,

the positioning member is the second shaft support portion,

when the operating mechanism is in a braking state, the movable iron core is separated from the electromagnetic core, and the movable iron core and the connecting member move to the first shaft supporting portion side,

when the operating mechanism is returned from the braking state to the standby state, the electromagnetic core is moved in a direction approaching the movable core by the rotation of the driving motor, and if the electromagnetic core is attracted to the movable core to restrict the movement of the electromagnetic core, the contact between the movable core and the electromagnetic core is judged by measuring the current value of the driving motor and comparing with a threshold value, and then the driving motor is rotated in a reverse direction, so that the electromagnetic core attracted to the movable core is moved in a direction toward the positioning member until the feed nut abuts on the positioning member, thereby returning to the standby state.