Elevator braking system

Abstract

The present invention provides an elevator braking device that allows a movable body to conform to the shape of the braking surface when it comes into contact with the braking surface of a rotating body, using a simple structure. [Solution] In the elevator brake device 56, a fixed shaft 15 is fixed to the electromagnetic magnet 13. The fixed shaft 15 is inserted into an insertion hole 143 provided in the movable body 14. Multiple springs 16 are arranged around the fixed shaft 15, generating an elastic restoring force in the direction that brings the movable body 14 into contact with the braking surface 111 of the brake drum 11. The electromagnetic magnet 13 generates an electromagnetic attractive force that attracts the movable body 14, thereby moving the movable body 14 away from the braking surface 111, against the elastic restoring force of the multiple springs 16. There is one fixed shaft 15. A gap is created between the inner surface of the insertion hole 143 and the fixed shaft 15.

Description

Technical Field

[0001] The present disclosure relates to an elevator braking device.

Background Art

[0002] Patent Document 1 discloses a braking device that applies a braking force to a brake drum by bringing a brake shoe into contact with the brake drum by the spring force of a spring. The brake shoe is connected to a movable iron core movable with respect to a fixed iron core via a connecting member. One end of the connecting member is screwed and attached to the brake shoe. The other end of the connecting member is press-fitted and attached to the movable iron core via a spherical seat and a flat seat by a leaf spring. Thereby, the brake shoe can swing with respect to the movable iron core, and the brake shoe when contacting the brake drum can follow the shape of the brake drum.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional braking device disclosed in Patent Document 1, the structure for connecting the brake shoe to the movable iron core becomes complicated and the number of parts increases.

[0005] The present disclosure solves the above problems, and an object thereof is to provide an elevator braking device that can cause a movable body to follow the shape of a braking surface with a simple structure when contacting the braking surface of a rotating body.

Means for Solving the Problems

[0006] The elevator brake device according to this disclosure comprises a rotating body provided with a braking surface and a brake device body positioned opposite the braking surface. The brake device body includes an electromagnetic magnet fixed at a position away from the braking surface, a movable body positioned between the braking surface and the electromagnetic magnet, a fixed shaft fixed to the electromagnetic magnet and inserted into an insertion hole provided in the movable body, and a plurality of springs arranged around the fixed shaft that generate an elastic restoring force in the direction that brings the movable body into contact with the braking surface. The electromagnetic magnet generates an electromagnetic attractive force that attracts the movable body, thereby moving the movable body away from the braking surface against the elastic restoring force of the plurality of springs. There is one fixed shaft, and a gap is created between the inner surface of the insertion hole and the fixed shaft. [Effects of the Invention]

[0007] According to the elevator braking device described herein, a movable body can be made to follow the shape of the braking surface with a simple structure when it comes into contact with the braking surface of a rotating body. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing an elevator according to Embodiment 1. [Figure 2] Figure 1 is a front view showing the hoisting machine. [Figure 3] This is a cross-sectional view along line III-III in Figure 2. [Figure 4] Figure 2 is a cross-sectional view showing the brake unit. [Figure 5] This is a cross-sectional view along the VV line in Figure 4. [Figure 6] Figure 4 is a cross-sectional view showing the movable body separated from the braking surface of the brake drum. [Figure 7] Figure 6 is a cross-sectional view showing the lining of the movable body in contact with the braking surface of the brake drum. [Figure 8] This is a cross-sectional view showing the positional relationship between the fixed shaft and multiple springs in the electromagnetic magnet of the brake device according to Embodiment 2. [Figure 9] This is a cross-sectional view showing the positional relationship between the fixed shaft and multiple springs in the electromagnetic magnet of the brake device according to Embodiment 3. [Figure 10] This is a cross-sectional view showing the positional relationship between the fixed shaft and multiple springs in the electromagnetic magnet of the brake device according to Embodiment 4. [Figure 11] This is a cross-sectional view showing the positional relationship between the fixed shaft and multiple springs in the electromagnetic magnet of the brake device according to Embodiment 5. [Figure 12] This is a cross-sectional view showing the positional relationship between the fixed shaft and multiple springs in the electromagnetic magnet of the brake device according to Embodiment 6. [Figure 13] This is a cross-sectional view showing the positional relationship between the fixed shaft and the multiple springs in the electromagnetic magnet of the brake device according to Embodiment 7. [Figure 14] This is a cross-sectional view along the line XIV-XIV in Figure 13. [Figure 15] This is a cross-sectional view showing the positional relationship between the fixed shaft and multiple springs in the electromagnetic magnet of the brake device according to Embodiment 8. [Figure 16] This is a cross-sectional view along the line XVI-XVI in Figure 15. [Figure 17] This is a cross-sectional view showing the positional relationship between the fixed shaft and multiple springs in the electromagnetic magnet of the brake device according to Embodiment 9. [Figure 18] This is a cross-sectional view along the line XVIII-XVIII in Figure 17. [Modes for carrying out the invention]

[0009] The embodiments for carrying out the subject matter of this disclosure will be described with reference to the attached figures. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are simplified or omitted as appropriate. The subject matter of this disclosure is not limited to the following embodiments, and any modification of any component of the embodiments or omission of any component of the embodiments is possible without departing from the spirit of this disclosure.

[0010] Embodiment 1. Figure 1 is a schematic configuration diagram showing an elevator according to Embodiment 1. In the figure, a machine room 2 is provided above the hoistway 1. Inside the hoistway 1, a car 3 and a counterweight 4 are provided so as to be movable in the vertical direction. Inside the machine room 2, a hoisting machine 5 and a deflecting sheave 6 are provided.

[0011] The hoisting machine 5 has a hoisting machine body 51 and a driving wire rope sheave 52. The driving wire rope sheave 52 is rotatably provided on the hoisting machine body 51. The hoisting machine body 51 generates a driving force for rotating the driving wire rope sheave 52 by supplying power to the hoisting machine body 51. The deflecting sheave 6 is provided at a position away from the driving wire rope sheave 52.

[0012] <{ A plurality of suspension bodies 7 are wound around the driving wire rope sheave 52 and the deflecting sheave 6. As the suspension body 7, a rope, a belt, etc. are used. The car 3 and the counterweight 4 are suspended in the hoistway 1 by a plurality of suspension bodies 7. The car 3 and the counterweight 4 move vertically in the hoistway 1 when the driving wire rope sheave 52 rotates by the driving force of the hoisting machine body 51.

[0013] Figure 2 is a front view showing the hoisting machine 5 of Figure 1. Figure 3 is a cross-sectional view taken along line III-III of Figure 2. The hoisting machine body 51 has a housing 53, a main shaft 54, a motor 55, and a brake device 56.

[0014] The main shaft 54 is fixed to the housing 53. The housing 53 is arranged in the machine room 2 with the axial direction X of the main shaft 54 horizontal.

[0015] As shown in Figure 2, the brake device 56 has a brake drum 11 and a plurality of brake units 12.

[0016] As shown in Figure 3, the brake drum 11 is a rotating body attached to the main shaft 54 ​​via a plurality of bearings 57. The brake drum 11 is rotatable relative to the main shaft 54 ​​about the axis of the main shaft 54. The drive sheave 52 is fixed to the brake drum 11. As a result, the drive sheave 52 rotates together with the brake drum 11. A cylindrical braking surface 111 is provided on the outer circumference of the brake drum 11, centered on the axis of the main shaft 54.

[0017] As shown in Figure 2, each brake unit 12 is provided in the housing 53 as the main body of the brake device. Each brake unit 12 is arranged around the brake drum 11. As a result, each brake unit 12 is positioned opposite the braking surface 111 of the brake drum 11. In this embodiment, the brake device 56 has two brake units 12.

[0018] Here, the horizontal direction perpendicular to the axial direction X of the main shaft 54 ​​is defined as the width direction Y of the hoisting machine 5, and the direction perpendicular to both the axial direction X of the main shaft 54 ​​and the width direction Y of the hoisting machine 5 is defined as the height direction Z of the hoisting machine 5. In this embodiment, one brake unit 12 is arranged on each side of the brake drum 11 in the width direction Y of the hoisting machine 5. The two brake units 12 are arranged symmetrically with respect to the axis of the main shaft 54 ​​in the width direction Y of the hoisting machine 5.

[0019] As shown in Figure 3, the motor 55 has a stator 551 and a rotor 552. The stator 551 is fixed to the housing 53. The rotor 552 is fixed to the brake drum 11.

[0020] The stator 551 and rotor 552 are both cylindrical in shape. Both the stator 551 and rotor 552 are arranged coaxially with the spindle 54. The rotor 552 is located inside the stator 551.

[0021] The stator 551 comprises a stator core 553 and stator coils 554. The stator core 553 is a cylindrical laminated core in which multiple electromagnetic steel plates are stacked in the axial direction X of the main shaft 54. The stator coils 554 are provided on the stator core 553. The stator 551 generates a rotating magnetic field by supplying power to the stator coils 554.

[0022] The rotor 552 has a rotor core 555 and permanent magnets 556. The rotor core 555 is a cylindrical core fixed to the brake drum 11. The permanent magnets 556 are fixed to the outer surface of the rotor core 555. The rotor 552 is positioned inside the stator 551 with the permanent magnets 556 facing the inner surface of the stator 551 with a gap in between. The rotor 552 rotates together with the drive sheave 52 and the brake drum 11 relative to the housing 53 and the stator 551 as the stator 551 generates a rotating magnetic field.

[0023] The elevator operation is controlled by a control device (not shown) installed in the machine room 2. The movement of the elevator car 3 is controlled by the motor 55 of the hoisting machine 5, which is controlled by the control device. When the movement of the elevator car 3 stops due to the control of the motor 55 of the hoisting machine 5 by the control device, the brakes of each brake unit 12 are applied by the control device. This applies braking force to the brake drum 11 and the drive sheave 52, holding the elevator car 3 in a stopped state. When the movement of the elevator car 3 begins, the brakes of each brake unit 12 are released by the control device. This releases the braking force applied to the brake drum 11 and the drive sheave 52, allowing the elevator car 3 to move.

[0024] Figure 4 is a cross-sectional view showing the brake unit 12 of Figure 2. Figure 5 is a cross-sectional view along the VV line of Figure 4. The brake unit 12 includes an electromagnetic magnet 13, a movable body 14, a fixed shaft 15, a plurality of springs 16, an elastic member 17, and a detection switch 19.

[0025] The electromagnetic magnet 13 is fixed to the housing 53. The electromagnetic magnet 13 is fixed at a position away from the braking surface 111 of the brake drum 11. The electromagnetic magnet 13 faces the braking surface 111 with a gap in between on the radially outer side of the brake drum 11.

[0026] The fixed shaft 15 is fixed to the electromagnetic magnet 13. There is one fixed shaft 15 fixed to the electromagnetic magnet 13. The fixed shaft 15 protrudes from the electromagnetic magnet 13 toward the braking surface 111. The fixed shaft 15 is cylindrical in shape. The fixed shaft 15 is positioned so that the direction along its axis P coincides with the radial direction of the brake drum 11. In this embodiment, the electromagnetic magnet 13 is positioned so that the direction along the axis P of the fixed shaft 15 coincides with the width direction Y of the hoisting machine 5.

[0027] The electromagnetic magnet 13 has a fixed iron core 131 and an electromagnetic coil 132.

[0028] The fixed core 131 is made of a magnetic material such as iron. The fixed core 131 is provided with a coil housing recess 133, a shaft fixing hole 134, and a connecting hole 135.

[0029] The axis P of the fixed shaft 15 coincides with the axis of the fixed core 131. The shaft fixing hole 134 and the connecting hole 135 are continuously provided in the fixed core 131 in a direction along the axis of the fixed core. The hole formed by the continuous shaft fixing hole 134 and the connecting hole 135 penetrates the fixed core 131. The fixed core 131 is positioned with the opening of the shaft fixing hole 134 facing the braking surface 111. The fixed shaft 15 is fixed to the fixed core 131 by being press-fitted into the shaft fixing hole 134. The inner diameter of the connecting hole 135 is smaller than the inner diameter of the shaft fixing hole 134 at the boundary between the connecting hole 135 and the shaft fixing hole 134.

[0030] The coil housing recess 133 is an annular groove surrounding the axis P of the fixed shaft 15. The fixed core 131 is positioned with the coil housing recess 133 facing the braking surface 111.

[0031] The electromagnetic coil 132 is provided on the fixed iron core 131, housed in a coil housing recess 133. The electromagnetic coil 132 is an annular coil surrounding the axis P of the fixed shaft 15. In this embodiment, the axis of the annular electromagnetic coil 132 coincides with the axis P of the fixed shaft 15. The electromagnetic magnet 13 is capable of supplying power to the electromagnetic coil 132.

[0032] The movable body 14 is positioned between the braking surface 111 and the electromagnetic magnet 13. The movable body 14 has a movable core 141 and a lining 142. The lining 142 is fixed to the movable core 141 as a friction material. The movable body 14 is positioned with the lining 142 facing the braking surface 111 and the movable core 141 facing the electromagnetic magnet 13.

[0033] The movable core 141 is made of a magnetic material such as iron. The movable core 141 has a movable core axis. The movable core 141 is positioned so that the movable core axis coincides with the axis P of the fixed shaft 15.

[0034] The movable core 141 is provided with an insertion hole 143. The insertion hole 143 is a recess that is open toward the electromagnetic magnet 13. The inner surface of the insertion hole 143 is a cylindrical surface centered on the axis of the movable core.

[0035] A fixed shaft 15 is inserted into the insertion hole 143. The inner diameter of the insertion hole 143 is larger than the shaft diameter of the fixed shaft 15. As a result, a gap is created between the inner surface of the insertion hole 143 and the fixed shaft 15. The movable body 14 is able to move in the space between the braking surface 111 and the electromagnetic magnet 13 while maintaining the state in which the fixed shaft 15 is inserted into the insertion hole 143.

[0036] Multiple springs 16 are arranged around the fixed shaft 15. Furthermore, the multiple springs 16 are compressed and positioned between the fixed core 131 and the movable core 141. As a result, each spring 16 generates an elastic restoring force in the direction that brings the movable body 14 into contact with the braking surface 111. In this embodiment, when viewing the electromagnetic magnet 13 along the axis P of the fixed shaft 15, four springs 16 are arranged at the four corners of the electromagnetic magnet 13. Also, in this embodiment, the spring constants of each spring 16 are the same. When the movable body 14 moves in the direction that contacts the braking surface 111, the gap between the electromagnetic magnet 13 and the movable body 14 expands.

[0037] When the movable body 14 reaches the braking surface 111, the lining 142 of the movable body 14 comes into contact with the braking surface 111. A frictional force is generated between the braking surface 111 and the lining 142 as the lining 142 comes into contact with the braking surface 111. As a result, braking force is applied to the brake drum 11.

[0038] As shown in Figure 5, the electromagnetic magnet 13 is provided with a rotation-stopping pin 20. The rotation-stopping pin 20 is located away from the fixed shaft 15. In this embodiment, the rotation-stopping pin 20 is located away from the fixed shaft 15 in the second reference direction. In the first reference direction, the rotation-stopping pin 20 is located at the same position as the axis P of the fixed shaft 15. The rotation-stopping pin 20 protrudes parallel to the fixed shaft 15 from the fixed core 131 toward the braking surface 111. The rotation-stopping pin 20 is inserted into a pin hole (not shown) provided in the movable core 141 of the movable body 14. A gap is created between the inner surface of the pin hole and the rotation-stopping pin 20. The movable body 14 moves through the space between the braking surface 111 and the electromagnetic magnet 13 while sliding the rotation-stopping pin 20. The rotation of the movable body 14 around the axis P of the fixed shaft 15 is suppressed by the movable body 14 engaging with the rotation-stopping pin 20.

[0039] The fixed core 131 is provided with multiple fixed-side spring support recesses 136 corresponding to each spring 16. In this embodiment, four fixed-side spring support recesses 136 are provided on the fixed core 131. Each fixed-side spring support recess 136 is open toward the movable body 14. A portion of the corresponding spring 16 is individually inserted into each fixed-side spring support recess 136. As a result, the position of each fixed-side spring support recess 136 coincides with the position of the corresponding spring 16 when the electromagnetic magnet 13 is viewed along the axis P of the fixed shaft 15, as shown in Figure 5.

[0040] The movable core 141 is provided with multiple movable spring support recesses 144 corresponding to each spring 16. In this embodiment, four movable spring support recesses 144 are provided on the movable core 141. Each movable spring support recess 144 is open toward the electromagnetic magnet 13. A portion of the corresponding spring 16 is individually inserted into each movable spring support recess 144. As a result, the position of each movable spring support recess 144 coincides with the position of the corresponding spring 16 when the movable body 14 is viewed along the axis P of the fixed shaft 15.

[0041] An elastic member groove 151 is provided on the outer circumferential surface of the fixed shaft 15, extending along the entire circumference of the fixed shaft 15. The elastic member groove 151 is provided in the portion of the fixed shaft 15 that is inserted into the insertion hole 143.

[0042] The elastic member 17 is attached to the fixed shaft 15 in a state where it is fitted into the groove 151 for the elastic member. The elastic member 17 is an annular member that is elastically deformable along the circumferential direction of the fixed shaft 15. A rubber O-ring or the like is used as the elastic member 17. When attached to the fixed shaft 15, the elastic member 17 is positioned in the gap between the inner surface of the insertion hole 143 and the fixed shaft 15. The movable body 14 is supported by the fixed shaft 15 via the elastic member 17.

[0043] Magnetic poles are formed in the electromagnetic magnet 13 by supplying power to the electromagnetic coil 132. Since the axis of the electromagnetic coil 132 coincides with the axis P of the fixed shaft 15, the centerlines of the magnetic poles formed in the electromagnetic magnet 13 coincide with the axis P of the fixed shaft 15. An electromagnetic attractive force is applied to the movable body 14 due to the formation of magnetic poles in the electromagnetic magnet 13, causing it to be attracted to the electromagnetic magnet 13.

[0044] In other words, the electromagnetic magnet 13 generates an electromagnetic attractive force that attracts the movable body 14 when power is supplied to the electromagnetic coil 132. By generating this electromagnetic attractive force, the electromagnetic magnet 13 moves the movable body 14 away from the braking surface 111, that is, towards the electromagnetic magnet 13, against the elastic restoring force of the multiple springs 16. As a result, the braking force applied to the brake drum 11 is released.

[0045] As the movable body 14 moves against the elastic restoring force of the multiple springs 16, it reaches a release completion position where the electromagnetic magnet 13 receives the movable body 14. In this embodiment, when the movable body 14 reaches the release completion position, the movable iron core 141 comes into contact with the fixed iron core 131.

[0046] Each brake unit 12 performs a brake release operation when power is supplied to the electromagnetic coil 132, and performs a brake application operation when power is stopped from being supplied to the electromagnetic coil 132.

[0047] The fixed shaft 15 is provided with a bolt hole 152. The bolt hole 152 is a through hole that penetrates the fixed shaft 15 along its axis P. The bolt hole 152 is located on the axis P of the fixed shaft 15. As a result, the bolt hole 152 is located on the extension of the connecting hole 135 in the direction along the axis P of the fixed shaft 15.

[0048] A screw hole 145 is provided at the bottom of the insertion hole 143. The screw hole 145 is located on the axis of the movable iron core. As a result, the screw hole 145 is located on the extension of the bolt hole 152 of the fixed shaft 15.

[0049] When repairing or maintaining the hoisting machine 5, the application of braking force to the brake drum 11 may be forcibly released by holding the movable body 14 away from the braking surface 111 while the power supply to the electromagnetic coil 132 is stopped. In this case, a long bolt 18 is used to hold the movable body 14 away from the braking surface 111.

[0050] When the braking force applied to the brake drum 11 is forcibly released, the long bolt 18 is passed sequentially through the connecting hole 135 and the bolt-through hole 152 from the outside of the electromagnetic magnet 13 and screwed into the threaded hole 145. By increasing the amount the long bolt 18 is screwed into the threaded hole 145, the movable body 14 moves in a direction closer to the electromagnetic magnet 13 and is held in a position away from the braking surface 111. This forcibly releases the braking force applied to the brake drum 11. During normal elevator operation, the long bolt 18 is removed from the threaded hole 145.

[0051] The detection switch 19 is provided on the electromagnetic magnet 13. The detection switch 19 detects when the movable body 14 has reached the release completion position. In this embodiment, a contact-type switch that detects when the movable body 14 has reached the release completion position by contacting the movable body 14 is used as the detection switch 19.

[0052] The control device detects the completion of the brake release operation when the detection switch 19 detects that the movable body 14 has reached the release completion position. After detecting the completion of the brake release operation, the control device controls the movement of the car 3.

[0053] Here, a specific direction perpendicular to the magnetic pole centerline of the electromagnetic magnet 13 is defined as the first reference direction. In this case, the detection switch 19 is positioned away from the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction. In this embodiment, the first reference direction coincides with the axial direction X of the main shaft 54. Therefore, in this embodiment, as shown in Figure 5, the detection switch 19 is positioned away from the axis P of the fixed shaft 15 in the axial direction X of the main shaft 54. Also, in this embodiment, the detection switch 19 is fixed to the side surface of the fixed core 131.

[0054] Furthermore, the second reference direction is defined as the direction perpendicular to the magnetic pole centerline of the electromagnetic magnet 13 and also perpendicular to the first reference direction. In this case, the detection switch 19 is positioned at the same location as the magnetic pole centerline of the electromagnetic magnet 13 in the second reference direction. In this embodiment, the second reference direction coincides with the height direction Z of the hoisting machine 5. Therefore, in this embodiment, as shown in Figure 5, the detection switch 19 is positioned at the same location as the axis P of the fixed shaft 15 in the height direction Z of the hoisting machine 5.

[0055] In the first reference direction, two of the four springs 16 are positioned as switch-side springs on the side closer to the detection switch 19, relative to the position of the magnetic pole centerline of the electromagnetic magnet 13. Also, in the first reference direction, on the side opposite to the detection switch 19, relative to the position of the magnetic pole centerline of the electromagnetic magnet 13, two of the four springs 16 corresponding to the switch-side springs 16 are positioned as anti-switch-side springs.

[0056] The four springs 16 are positioned asymmetrically with respect to the position of the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction. The distance in the first reference direction from the position of each switch-side spring 16 to the position of the magnetic pole centerline of the electromagnetic magnet 13 is the switch-side distance L1. The distance in the first reference direction from the position of each non-switch-side spring 16 corresponding to each switch-side spring 16 to the position of the magnetic pole centerline of the electromagnetic magnet 13 is the non-switch-side distance L2. The switch-side distance L1 is greater than the non-switch-side distance L2.

[0057] The springs 16 on the switch side are positioned one on each side of the position of the magnetic pole centerline of the electromagnetic magnet 13 in the second reference direction, and the springs 16 on the non-switch side are also positioned one on each side of the position of the magnetic pole centerline of the electromagnetic magnet 13 in the second reference direction. The four springs 16 are positioned symmetrically with respect to the position of the magnetic pole centerline of the electromagnetic magnet 13 in the second reference direction.

[0058] Because the switch-side distance L1 is greater than the non-switch-side distance L2, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position before the part closer to the detection switch 19. That is, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position first, followed by the part of the movable body 14 closer to the detection switch 19. When the entire movable body 14 reaches the release completion position, the detection switch 19 detects that the movable body 14 has reached the release completion position, and the control device detects that the brake release operation is complete.

[0059] Next, the operation of the hoisting machine 5 will be described. Figure 6 is a cross-sectional view showing the state in which the movable body 14 of Figure 4 is separated from the braking surface 111 of the brake drum 11. In Figure 6, due to the assembly tolerances of the hoisting machine 5, the electromagnetic magnet 13 is fixed at a position that is offset by a dimension A from the design position in which the axis P of the fixed shaft 15 is perpendicular to the braking surface 111 of the brake drum 11.

[0060] During normal elevator operation, when the car 3 and counterweight 4 are moving due to the driving force of the hoisting machine 5, the electromagnetic magnets 13 in each brake unit 12 generate an electromagnetic attractive force due to the power supply to the electromagnetic coil 132 under the control of the control device. As a result, the state in which the lining 142 of the movable body 14 is separated from the braking surface 111 of the brake drum 11 is maintained, and the application of braking force to the drive sheave 52 and the brake drum 11 is released.

[0061] When the rotation of the drive sheave 52 is stopped by the control of the motor 55 of the hoisting machine 5 by the control device, the power supply to the electromagnetic coils 132 of each brake unit 12 is stopped by the control device. In each brake unit 12, when the power supply to the electromagnetic coils 132 is stopped, the movable body 14 moves in the direction of contact with the braking surface 111 due to the elastic restoring force of each spring 16. After this, when the lining 142 of the movable body 14 comes into contact with the braking surface 111, a braking force is applied to the brake drum 11 and the drive sheave 52.

[0062] Figure 7 is a cross-sectional view showing the state in which the lining 142 of the movable body 14 in Figure 6 is in contact with the braking surface 111 of the brake drum 11. When the lining 142 of the movable body 14 comes into contact with the braking surface 111, the lining 142 follows the shape of the braking surface 111, and the attitude of the movable body 14 with respect to the axis P of the fixed shaft 15 is adjusted. At this time, if the position of the electromagnetic magnet 13 is deviated from the design position as shown in Figure 6, the lining 142 follows the shape of the braking surface 111, causing the elastic member 17 to elastically deform between the inner surface of the insertion hole 143 and the fixed shaft 15, and the inclination of the movable body 14 with respect to the axis P of the fixed shaft 15 is automatically adjusted. Also, at this time, the amount of contraction of each spring 16 is automatically adjusted according to the inclination of the movable body 14 with respect to the axis P of the fixed shaft 15. As a result, the elastic restoring force of each spring 16 presses the lining 142 against the braking surface 111, thereby applying braking force to the brake drum 11.

[0063] Subsequently, when the movement of the cage 3 begins, the control device starts supplying power to the electromagnetic coils 132 in each brake unit 12. This generates an electromagnetic magnet that attracts the movable body 14, causing the movable body 14 to move toward the electromagnetic magnet 13 against the elastic restoring force of each spring 16. When the movable body 14 moves toward the electromagnetic magnet 13 against the elastic restoring force of each spring 16, the lining 142 separates from the braking surface 111, and the application of braking force to the brake drum 11 is released.

[0064] Subsequently, when the movable body 14 reaches the release completion position, the detection switch 19 detects the movable body 14. At this time, since the switch-side distance L1 is greater than the non-switch-side distance L2, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position first, followed by the part of the movable body 14 closer to the detection switch 19. The detection switch 19 detects the movable body 14 when the part of the movable body 14 closer to the detection switch 19 reaches the release completion position.

[0065] When the detection switch 19 detects the movable body 14, the control device detects that the brake release operation is complete, and the movement of the cage 3 begins through control of the motor 55 of the hoisting machine 5 by the control device.

[0066] In this type of brake device 56, a fixed shaft 15 is fixed to an electromagnetic magnet 13. The fixed shaft 15 is inserted into an insertion hole 143 provided in the movable body 14. A gap exists between the inner surface of the insertion hole 143 and the fixed shaft 15. Multiple springs 16 are arranged around the fixed shaft 15. The multiple springs 16 generate an elastic restoring force in the direction that brings the movable body 14 into contact with the braking surface 111 of the brake drum 11. The electromagnetic magnet 13 generates an electromagnetic attractive force that moves the movable body 14 away from the braking surface 111, against the elastic restoring force of the multiple springs 16.

[0067] Therefore, the orientation of the movable body 14 with respect to the axis P of the fixed shaft 15 can be freely adjusted without using complex structures such as spherical seats or flat seats. This allows the movable body 14 to follow the braking surface 111 of the brake drum 11 with a simple structure when it comes into contact with the braking surface 111. Consequently, the cost of the brake device 56 can be reduced. Furthermore, even when rotational force is applied to the brake drum 11, the movable body 14, which tries to move in conjunction with the rotation of the brake drum 11, can be supported by the fixed shaft 15. This allows braking force to be applied to the brake drum 11 more reliably.

[0068] Furthermore, when viewing the electromagnetic magnet 13 along the axis P of the fixed shaft 15, the four springs 16 are positioned at the four corners of the electromagnetic magnet 13. This allows the movable body 14 to make stable contact with the braking surface 111 of the brake drum 11. As a result, braking force can be applied to the brake drum 11 more stably.

[0069] Furthermore, the electromagnetic magnet 13 is provided with a rotation-stopping pin 20. The rotation-stopping pin 20 is located away from the fixed shaft 15. The rotation-stopping pin 20 protrudes from the electromagnetic magnet 13 toward the braking surface 111. The rotation-stopping pin 20 is inserted into a pin hole provided in the movable body 14. Therefore, even if the movable body 14 attempts to rotate around the fixed shaft 15, the movable body 14 can be made to engage with the rotation-stopping pin 20. This makes it possible to suppress the rotation of the movable body 14 around the fixed shaft 15.

[0070] Furthermore, an elastic member 17 is placed in the gap between the inner surface of the insertion hole 143 and the fixed shaft 15. This allows the movable body 14 to be supported by the fixed shaft 15 via the elastic member 17. This stabilizes the posture of the movable body 14 relative to the fixed shaft 15. In addition, since contact between the movable body 14 and the fixed shaft 15 can be suppressed, problems such as wear, damage, and noise caused by contact between the movable body 14 and the fixed shaft 15 can be suppressed.

[0071] Furthermore, the distance in the first reference direction from the position of the spring 16 on the switch side to the position of the magnetic pole centerline, i.e., the switch-side distance L1, is greater than the distance in the first reference direction from the position of the corresponding spring 16 on the non-switch side to the position of the magnetic pole centerline, i.e., the non-switch-side distance L2. Therefore, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position first, followed by the part of the movable body 14 closer to the detection switch 19. This allows the detection switch 19 to more reliably detect that the entire movable body 14 has reached the release completion position, and thus more reliably detect the completion of the brake release operation. Consequently, it is possible to prevent the drive sheave 52 and brake drum 11 from rotating due to the driving force of the motor 55 of the hoisting machine 5 before the brake release operation is completed. This suppresses the progression of wear of the lining 142 of the movable body 14, and extends the lifespan of the movable body 14.

[0072] Embodiment 2. Figure 8 is a cross-sectional view showing the positional relationship between the fixed shaft 15 and the multiple springs 16 in the electromagnetic magnet 13 of the brake device 56 according to Embodiment 2. Figure 8 corresponds to Figure 5 in Embodiment 1. In this embodiment, six springs 16 are arranged around the fixed shaft 15. In this embodiment, the spring constants of each spring 16 are the same. In this embodiment, six fixed-side spring support recesses 136 corresponding to each spring 16 are provided in the fixed core 131, and a portion of each spring 16 is individually inserted into the corresponding fixed-side spring support recess 136. Furthermore, in this embodiment, six movable-side spring support recesses 144 corresponding to each spring 16 are provided in the movable core 141, and a portion of each spring 16 is individually inserted into the corresponding movable-side spring support recess 144. In this embodiment, the depth dimensions of the six fixed-side spring support recesses 136 are the same, and the depth dimensions of the six movable-side spring support recesses 144 are the same.

[0073] Of the six springs 16, four are positioned in the same locations as in Embodiment 1. Therefore, in this embodiment as well, the switch-side distance L1 is greater than the non-switch-side distance L2, similar to Embodiment 1.

[0074] Of the six springs 16, the remaining two springs 16 are positioned as central springs at the same location as the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction. One central spring 16 is positioned on each side of the magnetic pole centerline of the electromagnetic magnet 13 in the second reference direction. The two central springs 16 are positioned symmetrically with respect to the magnetic pole centerline of the electromagnetic magnet 13 in the second reference direction. The rotation-preventing pin 20 is positioned further from the fixed shaft 15 than the central springs 16 in the second reference direction.

[0075] Since each central spring 16 is positioned at the same location as the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the elastic restoring force of each central spring 16 does not affect the bias of the movement of the movable body 14 in the first reference direction. Therefore, when the electromagnetic magnet 13 generates an electromagnetic attractive force, similar to Embodiment 1, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position first, followed by the part of the movable body 14 closer to the detection switch 19 reaching the release completion position. Other configurations and operations are the same as in Embodiment 1.

[0076] Thus, even with six springs 16, the movable body 14 can be made to follow the braking surface 111 of the brake drum 11 with a simple structure when it comes into contact with the braking surface 111. Furthermore, even if two central springs 16 are added to the four springs 16 in Embodiment 1, the detection switch 19 can more reliably detect that the entire movable body 14 has reached the release completion position, similar to Embodiment 1.

[0077] Embodiment 3. Figure 9 is a cross-sectional view showing the positional relationship between the fixed shaft 15 and the multiple springs 16 in the electromagnetic magnet 13 of the brake device 56 according to Embodiment 3. Figure 9 corresponds to Figure 5 in Embodiment 1. In this embodiment, eight springs 16 are arranged around the fixed shaft 15. In this embodiment, the spring constants of each spring 16 are the same. In this embodiment, eight fixed-side spring support recesses 136 corresponding to each spring 16 are provided in the fixed core 131, and a portion of each spring 16 is individually inserted into the corresponding fixed-side spring support recess 136. Furthermore, in this embodiment, eight movable-side spring support recesses 144 corresponding to each spring 16 are provided in the movable core 141, and a portion of each spring 16 is individually inserted into the corresponding movable-side spring support recess 144. In this embodiment, the depth dimensions of the eight fixed-side spring support recesses 136 are the same, and the depth dimensions of the eight movable-side spring support recesses 144 are the same.

[0078] In the first reference direction, four of the eight springs 16 are positioned as switch-side springs on the side closer to the detection switch 19, relative to the position of the magnetic pole centerline of the electromagnetic magnet 13. Also, in the first reference direction, on the side opposite to the detection switch 19, relative to the position of the magnetic pole centerline of the electromagnetic magnet 13, four of the eight springs 16 corresponding to the switch-side springs 16 are positioned as anti-switch-side springs.

[0079] The eight springs 16 are positioned asymmetrically with respect to the position of the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction. As a result, the four switch-side springs 16 and the four non-switch-side springs 16 are positioned asymmetrically with respect to the position of the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction.

[0080] Of the four switch-side springs 16, two are designated as the first switch-side springs, and the remaining two are designated as the second switch-side springs. Each first switch-side spring 16 is positioned closer to the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction than each second switch-side spring 16.

[0081] The distance in the first reference direction from the position of the first spring 16 on each switch side to the position of the magnetic pole centerline of the electromagnetic magnet 13 is the switch-side first distance L11. The distance in the first reference direction from the position of the second spring 16 on each switch side to the position of the magnetic pole centerline of the electromagnetic magnet 13 is the switch-side second distance L12.

[0082] The distance in the first reference direction from the positions of the two non-switch springs 16 corresponding to the two first switch springs 16 to the position of the magnetic pole centerline of the electromagnetic magnet 13 is the first non-switch distance L21. The distance in the first reference direction from the positions of the two non-switch springs 16 corresponding to the two second switch springs 16 to the position of the magnetic pole centerline of the electromagnetic magnet 13 is the second non-switch distance L22.

[0083] The first distance L11 on the switch side is greater than the first distance L21 on the opposite side of the switch. The second distance L12 on the switch side is greater than the second distance L22 on the opposite side of the switch.

[0084] The springs 16 on the switch side are arranged in pairs on each side of the position of the magnetic pole centerline of the electromagnetic magnet 13 in the second reference direction, and the springs 16 on the non-switch side are also arranged in pairs on each side of the position of the magnetic pole centerline of the electromagnetic magnet 13 in the second reference direction. The eight springs 16 are arranged symmetrically with respect to the position of the magnetic pole centerline of the electromagnetic magnet 13 in the second reference direction.

[0085] Multiple cushioning members 21 are positioned between the fixed core 131 of the electromagnetic magnet 13 and the movable core 141 of the movable body 14. The multiple cushioning members 21 are arranged around the fixed shaft 15. In this embodiment, four cushioning members 21 are positioned at the four corners of the electromagnetic magnet 13. Each cushioning member 21 is made of a porous material. Each cushioning member 21 reduces the impact received by the electromagnetic magnet 13 and the movable body 14 when the movable body 14 reaches the release completion position. The fixed core 131 may be provided with recesses that determine the position of the cushioning members 21.

[0086] In the brake unit 12, the first distance L11 on the switch side is greater than the first distance L21 on the non-switch side, and the second distance L12 on the switch side is greater than the second distance L22 on the non-switch side. As a result, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 that is farther from the detection switch 19 reaches the release completion position before the part that is closer to the detection switch 19, similar to the first embodiment. That is, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 that is farther from the detection switch 19 reaches the release completion position first, and then the part of the movable body 14 that is closer to the detection switch 19 reaches the release completion position. Other configurations and operations are the same as in the first embodiment.

[0087] Thus, even with eight springs 16, the movable body 14 can be made to follow the braking surface 111 of the brake drum 11 with a simple structure when it comes into contact with the braking surface 111. Furthermore, the first distance L11 on the switch side is greater than the first distance L21 on the opposite side of the switch, and the second distance L12 on the switch side is greater than the second distance L22 on the opposite side of the switch. Therefore, when the electromagnetic magnet 13 generates an electromagnetic attractive force, similar to the first embodiment, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position first, followed by the part of the movable body 14 closer to the detection switch 19. This allows the detection switch 19 to more reliably detect that the entire movable body 14 has reached the release completion position.

[0088] Furthermore, multiple cushioning members 21 are positioned between the electromagnetic magnet 13 and the movable body 14 to mitigate the impact received by the electromagnetic magnet 13 and the movable body 14 when the movable body 14 reaches the release completion position. This suppresses the occurrence of problems such as noise when the movable body 14 reaches the release completion position and damage to the electromagnetic magnet 13 and the movable body 14.

[0089] Embodiment 4. Figure 10 is a cross-sectional view showing the positional relationship between the fixed shaft 15 and the multiple springs 16 in the electromagnetic magnet 13 of the brake device 56 according to Embodiment 4. Figure 10 corresponds to Figure 5 in Embodiment 1. The four springs 16 are arranged symmetrically with respect to the position of the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction. Therefore, the switch-side distance L1 and the anti-switch-side distance L2 are the same.

[0090] Each of the two switch-side springs 16 is a specific spring 16a. The spring constant of the specific spring 16a is higher than the spring constants of the other springs 16. The spring constants of the other springs 16 are the same as those of the other springs 16.

[0091] As a result, when the electromagnetic magnet 13 generates an electromagnetic attractive force, similar to Embodiment 1, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position, followed by the part of the movable body 14 closer to the detection switch 19 reaching the release completion position. Other configurations and operations are the same as in Embodiment 1.

[0092] In this type of brake device 56, each of the two switch-side springs 16 is a specific spring 16a. The spring constant of the specific spring 16a is higher than that of the other springs 16. Therefore, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position first, followed by the part of the movable body 14 closer to the detection switch 19. This allows the detection switch 19 to more reliably detect that the entire movable body 14 has reached the release completion position, and thus more reliably detect the completion of the brake release operation. Consequently, the progression of wear of the lining 142 of the movable body 14 can be suppressed, and the lifespan of the movable body 14 can be extended.

[0093] In Embodiment 4, each of the two switch-side springs 16 is a specific spring 16a. However, it is sufficient if at least one of the two switch-side springs 16 is a specific spring 16a. In this case, the spring constant of the specific spring 16a is set higher than the spring constant of the other springs 16. This way, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position, and then the part of the movable body 14 closer to the detection switch 19 reaches the release completion position.

[0094] Embodiment 5. Figure 11 is a cross-sectional view showing the positional relationship between the fixed shaft 15 and the multiple springs 16 in the electromagnetic magnet 13 of the brake device 56 according to Embodiment 5. Figure 11 corresponds to Figure 8 in Embodiment 2. Of the six springs 16, the two switch-side springs 16 and the two non-switch-side springs 16 are positioned symmetrically with respect to the position of the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction. Therefore, the switch-side distance L1 and the non-switch-side distance L2 are the same.

[0095] Each of the two switch-side springs 16 is a specific spring 16a. The spring constant of the specific spring 16a is higher than the spring constants of the other springs 16. The spring constants of the other springs 16 are the same as those of the other springs 16.

[0096] As a result, when the electromagnetic magnet 13 generates an electromagnetic attractive force, similar to Embodiment 1, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position, followed by the part of the movable body 14 closer to the detection switch 19 reaching the release completion position. The other configurations and operations are the same as in Embodiment 2.

[0097] Thus, of the six springs 16, each of the two switch-side springs 16 is a specific spring 16a. The spring constant of the specific spring 16a is higher than that of the other springs 16. Therefore, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position first, followed by the part of the movable body 14 closer to the detection switch 19. This allows the detection switch 19 to more reliably detect that the entire movable body 14 has reached the release completion position, and thus more reliably detect the completion of the brake release operation.

[0098] In embodiments 4 and 5, each of the two switch-side springs 16 is a specific spring 16a. However, it is sufficient if at least one of the two switch-side springs 16 is a specific spring 16a. In this case, the spring constant of the specific spring 16a is set higher than the spring constant of the other springs 16. In this way, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position, and then the part of the movable body 14 closer to the detection switch 19 reaches the release completion position.

[0099] Embodiment 6. Figure 12 is a cross-sectional view showing the positional relationship between the fixed shaft 15 and the multiple springs 16 in the electromagnetic magnet 13 of the brake device 56 according to Embodiment 6. Figure 12 corresponds to Figure 9 in Embodiment 3. Of the eight springs 16, the four switch-side springs 16 and the four anti-switch-side springs 16 corresponding to each switch-side spring 16 are arranged symmetrically with respect to the position of the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction. Therefore, the first switch-side distance L11 and the first anti-switch-side distance L21 are the same. Also, the second switch-side distance L12 and the second anti-switch-side distance L22 are the same.

[0100] Each of the four switch-side springs 16 is a specific spring 16a. The spring constant of the specific spring 16a is higher than that of the other springs 16. The spring constants of the other springs 16 are the same as those of the other springs 16.

[0101] As a result, when the electromagnetic magnet 13 generates an electromagnetic attractive force, similar to Embodiment 1, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position, followed by the part of the movable body 14 closer to the detection switch 19 reaching the release completion position. Other configurations and operations are the same as in Embodiment 3.

[0102] Thus, of the eight springs 16, each of the four switch-side springs 16 is a specific spring 16a. The spring constant of the specific spring 16a is higher than that of the other springs 16. Therefore, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position first, followed by the part of the movable body 14 closer to the detection switch 19. This allows the detection switch 19 to more reliably detect that the entire movable body 14 has reached the release completion position, and thus more reliably detect the completion of the brake release operation.

[0103] Thus, of the eight springs 16, each of the four switch-side springs 16 is a specific spring 16a. The spring constant of the specific spring 16a is higher than that of the other springs 16. Therefore, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position first, followed by the part of the movable body 14 closer to the detection switch 19. This allows the detection switch 19 to more reliably detect that the entire movable body 14 has reached the release completion position, and thus more reliably detect the completion of the brake release operation.

[0104] In Embodiment 6, each of the four switch-side springs 16 is a specific spring 16a. However, it is sufficient if at least one of the four switch-side springs 16 is a specific spring 16a. In this case, the spring constant of the specific spring 16a is set higher than the spring constant of the other springs 16. This ensures that when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position before the part of the movable body 14 closer to the detection switch 19 reaches the release completion position.

[0105] Embodiment 7. Figure 13 is a cross-sectional view showing the positional relationship between the fixed shaft 15 and the multiple springs 16 in the electromagnetic magnet 13 of the brake device 56 according to Embodiment 7. Figure 14 is a cross-sectional view along the line XIV-XIV in Figure 13. Figure 13 corresponds to Figure 10 in Embodiment 4. The four springs 16 are arranged symmetrically with respect to the position of the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction. Therefore, the switch-side distance L1 and the anti-switch-side distance L2 are the same. Also, the spring constants of each of the four springs 16 are the same.

[0106] Of the four fixed-side spring receiving recesses 136, each of the two fixed-side spring receiving recesses 136 into which the switch-side spring 16 is inserted is designated as a specific spring receiving recess 136a. The depth dimension D1 of the specific spring receiving recess 136a is smaller than the depth dimension D2 of the other fixed-side spring receiving recesses 136. The depth dimension D2 of each fixed-side spring receiving recess 136 other than the specific spring receiving recess 136a is the same as that of the other fixed-side spring receiving recesses 136.

[0107] The natural lengths of the four springs 16 are the same. Therefore, the amount of compression of each switch-side spring 16 inserted into the specific spring receiving recess 136a is greater than the amount of compression of each anti-switch-side spring 16 inserted into the fixed-side spring receiving recess 136 other than the specific spring receiving recess 136a. As a result, the elastic restoring force of each switch-side spring 16 is greater than the elastic restoring force of each anti-switch-side spring 16.

[0108] As a result, when the electromagnetic magnet 13 generates an electromagnetic attractive force, similar to Embodiment 1, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position, followed by the part of the movable body 14 closer to the detection switch 19 reaching the release completion position. The other configurations and operations are the same as in Embodiment 4.

[0109] In this type of brake device 56, of the four fixed-side spring receiving recesses 136, each of the two fixed-side spring receiving recesses 136 into which the switch-side spring 16 is inserted is designated as a specific spring receiving recess 136a. The depth dimension D1 of the specific spring receiving recess 136a is smaller than the depth dimension D2 of the other fixed-side spring receiving recesses 136. Therefore, by inserting springs 16 with the same natural length into each fixed-side spring receiving recess 136, the elastic restoring force of the spring 16 inserted into the specific spring receiving recess 136a can be made greater than the elastic restoring force of the springs 16 inserted into the other fixed-side spring receiving recesses 136. As a result, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position first, followed by the part of the movable body 14 closer to the detection switch 19. Therefore, the detection switch 19 can more reliably detect that the entire movable body 14 has reached the release completion position, and the completion of the brake release operation can be detected more reliably.

[0110] Embodiment 8. Figure 15 is a cross-sectional view showing the positional relationship between the fixed shaft 15 and the multiple springs 16 in the electromagnetic magnet 13 of the brake device 56 according to Embodiment 8. Figure 16 is a cross-sectional view along the line XVI-XVI in Figure 15. Figure 15 corresponds to Figure 11 in Embodiment 5. Of the six springs 16, the two switch-side springs 16 and the two anti-switch-side springs 16 are positioned symmetrically with respect to the position of the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction. Therefore, the switch-side distance L1 and the anti-switch-side distance L2 are the same.

[0111] Of the six fixed-side spring receiving recesses 136, each of the two fixed-side spring receiving recesses 136 into which the switch-side spring 16 is inserted is designated as a specific spring receiving recess 136a. The depth dimension D1 of the specific spring receiving recess 136a is smaller than the depth dimension D2 of the other fixed-side spring receiving recesses 136. The depth dimension D2 of each fixed-side spring receiving recess 136 other than the specific spring receiving recess 136a is the same.

[0112] The natural lengths of each of the six springs 16 are the same. Therefore, the amount of compression of each switch-side spring 16 inserted into the specific spring receiving recess 136a is greater than the amount of compression of each non-switch-side spring 16 inserted into the fixed-side spring receiving recess 136 other than the specific spring receiving recess 136a. As a result, the elastic restoring force of each switch-side spring 16 is greater than the elastic restoring force of the springs 16 other than the switch-side springs 16.

[0113] As a result, when the electromagnetic magnet 13 generates an electromagnetic attractive force, similar to Embodiment 1, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position, followed by the part of the movable body 14 closer to the detection switch 19 reaching the release completion position. The other configurations and operations are the same as in Embodiment 5.

[0114] Thus, of the six fixed-side spring receiving recesses 136, the two fixed-side spring receiving recesses 136 into which the switch-side spring 16 is inserted are designated as specific spring receiving recesses 136a. The depth dimension D1 of the specific spring receiving recess 136a is smaller than the depth dimension D2 of the fixed-side spring receiving recesses 136 other than the specific spring receiving recess 136a. Therefore, by inserting springs 16 with the same natural length into each fixed-side spring receiving recess 136, the elastic restoring force of the spring 16 inserted into the specific spring receiving recess 136a can be made greater than the elastic restoring force of the springs 16 inserted into the fixed-side spring receiving recesses 136 other than the specific spring receiving recess 136a. As a result, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position first, followed by the part of the movable body 14 closer to the detection switch 19. Therefore, the detection switch 19 can more reliably detect that the entire movable body 14 has reached the release completion position, and the completion of the brake release operation can be detected more reliably.

[0115] In embodiments 7 and 8, each of the two fixed-side spring receiving recesses 136 into which the switch-side spring 16 is inserted is a specific spring receiving recess 136a. However, it is sufficient if at least one of the two fixed-side spring receiving recesses 136 into which the switch-side spring 16 is inserted is a specific spring receiving recess 136a. In this case, the depth dimension D1 of the specific spring receiving recess 136a is made smaller than the depth dimension D2 of the fixed-side spring receiving recesses 136 other than the specific spring receiving recess 136a. In this way, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position, and then the part of the movable body 14 closer to the detection switch 19 reaches the release completion position.

[0116] Embodiment 9. Figure 17 is a cross-sectional view showing the positional relationship between the fixed shaft 15 and the multiple springs 16 in the electromagnetic magnet 13 of the brake device 56 according to Embodiment 9. Figure 18 is a cross-sectional view along the line XVIII-XVIII in Figure 17. Figure 17 corresponds to Figure 12 in Embodiment 6. Of the eight springs 16, the four switch-side springs 16 and the four anti-switch-side springs 16 corresponding to each switch-side spring 16 are arranged symmetrically with respect to the position of the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction. Therefore, the first switch-side distance L11 and the first anti-switch-side distance L21 are the same. Also, the second switch-side distance L12 and the second anti-switch-side distance L22 are the same.

[0117] Of the four fixed-side spring receiving recesses 136 into which the switch-side spring 16 is inserted, only the two fixed-side spring receiving recesses 136 into which the first switch-side spring 16 is inserted are designated as specific spring receiving recesses 136a. The depth dimension D1 of the specific spring receiving recess 136a is smaller than the depth dimension D2 of the other fixed-side spring receiving recesses 136. The depth dimension D2 of each fixed-side spring receiving recess 136 other than the specific spring receiving recess 136a is the same.

[0118] The natural lengths of each of the eight springs 16 are the same. Therefore, the amount of compression of each switch-side spring 16 inserted into the specific spring receiving recess 136a is greater than the amount of compression of each non-switch-side spring 16 inserted into the fixed-side spring receiving recess 136 other than the specific spring receiving recess 136a. As a result, the elastic restoring force of each switch-side first spring 16 is greater than the elastic restoring force of the other springs 16 on the switch side.

[0119] As a result, when the electromagnetic magnet 13 generates an electromagnetic attractive force, similar to Embodiment 1, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position, followed by the part of the movable body 14 closer to the detection switch 19 reaching the release completion position. The other configurations and operations are the same as in Embodiment 6.

[0120] Thus, of the eight fixed-side spring receiving recesses 136, only the two fixed-side spring receiving recesses 136 into which the first spring 16 on the switch side is inserted are designated as specific spring receiving recesses 136a. The depth dimension D1 of the specific spring receiving recesses 136a is smaller than the depth dimension D2 of the fixed-side spring receiving recesses 136 other than the specific spring receiving recesses 136a. Therefore, by inserting springs 16 with the same natural length into each fixed-side spring receiving recess 136, the elastic restoring force of the spring 16 inserted into the specific spring receiving recess 136a can be made greater than the elastic restoring force of the springs 16 inserted into the fixed-side spring receiving recesses 136 other than the specific spring receiving recesses 136a. As a result, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position first, followed by the part of the movable body 14 closer to the detection switch 19. Therefore, the detection switch 19 can more reliably detect that the entire movable body 14 has reached the release completion position, and the completion of the brake release operation can be detected more reliably.

[0121] In Embodiment 9, the two fixed-side spring receiving recesses 136 into which the first spring 16 on the switch side is inserted are designated as specific spring receiving recesses 136a. However, it is sufficient if at least one of the four fixed-side spring receiving recesses 136 into which the spring 16 on the switch side is inserted is designated as a specific spring receiving recess 136a. In this case, the depth dimension D1 of the specific spring receiving recess 136a is made smaller than the depth dimension D2 of the fixed-side spring receiving recesses 136 other than the specific spring receiving recess 136a. In this way, when the electromagnetic magnet 13 generates an electromagnetic attractive force, the part of the movable body 14 furthest from the detection switch 19 reaches the release completion position, and then the part of the movable body 14 closer to the detection switch 19 reaches the release completion position.

[0122] Furthermore, in embodiments 3, 6, and 9, the number of cushioning members 21 placed between the electromagnetic magnet 13 and the movable body 14 is four. However, the number of cushioning members 21 placed between the electromagnetic magnet 13 and the movable body 14 is not limited to four, and may be three or fewer, or five or more.

[0123] Furthermore, in embodiments 3, 6, and 9, multiple cushioning members 21 are arranged between the electromagnetic magnet 13 and the movable body 14. However, in embodiments 1, 2, 4, 5, 7, and 8, multiple cushioning members 21 may also be arranged between the electromagnetic magnet 13 and the movable body 14. In this case, the number of cushioning members 21 is not limited.

[0124] Furthermore, in each of the above embodiments, an elastic member 17 is placed in the gap between the inner surface of the insertion hole 143 and the fixed shaft 15. However, the elastic member 17 is not required. Even without the elastic member 17, the posture of the movable body 14 with respect to the axis P of the fixed shaft 15 can be freely adjusted, and the movable body 14 can be made to automatically follow the shape of the braking surface 111 when it comes into contact with the braking surface 111.

[0125] Furthermore, in each of the above embodiments, a screw hole 145 is provided at the bottom of the insertion hole 143. However, if it is not necessary to forcibly release the braking force applied to the brake drum 11 by the long bolt 18, the screw hole 145 may be omitted. In this case, the bolt through hole 152 provided in the fixed shaft 15 and the connecting hole 135 provided in the fixed core 131 may also be omitted. In this case, the insertion hole 143 may pass through the movable core 141, or it may pass through the movable core 141 and the lining 142 and pass through the entire movable body 14.

[0126] Furthermore, in each of the above embodiments, the axis P of the fixed shaft 15 coincides with the magnetic pole centerline of the electromagnetic magnet 13. However, the position of the axis P of the fixed shaft 15 may be offset from the position of the magnetic pole centerline of the electromagnetic magnet 13.

[0127] Furthermore, in each of the above embodiments, two or four springs 16 are arranged as switch-side springs on the side closer to the detection switch 19 when viewed from the position of the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction. However, it is sufficient that at least one spring 16 is arranged as a switch-side spring on the side closer to the detection switch 19 when viewed from the position of the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction. In this case, at least one spring 16 corresponding to the switch-side spring 16 is arranged as an anti-switch-side spring on the side opposite to the detection switch 19 when viewed from the position of the magnetic pole centerline of the electromagnetic magnet 13 in the first reference direction.

[0128] The configurations shown in the embodiments described above are merely examples of the content of this disclosure. The embodiments can be combined with other known technologies. Some parts of the configurations of the embodiments can be omitted or modified without departing from the gist of this disclosure.

[0129] Examples of aspects that may be included in this disclosure are listed below as an addendum. (Note 1) A rotating body provided with a braking surface, A brake device body positioned opposite the braking surface and Equipped with, The brake device body is An electromagnetic magnet fixed at a position away from the aforementioned braking surface, A movable body disposed between the braking surface and the electromagnetic magnet, A fixed shaft is fixed to the electromagnetic magnet and inserted into an insertion hole provided in the movable body, A plurality of springs are arranged around the fixed shaft and generate an elastic restoring force in the direction that brings the movable body into contact with the braking surface. It has, The electromagnetic magnet generates an electromagnetic attractive force that attracts the movable body, thereby moving the movable body away from the braking surface against the elastic restoring force of the plurality of springs. The number of fixed shafts is one. An elevator brake device in which a gap exists between the inner surface of the insertion hole and the fixed shaft. (Note 2) The elevator brake device according to Appendix 1, wherein, when the electromagnetic magnet is viewed along the axis of the fixed shaft, the four springs are arranged at the four corners of the electromagnetic magnet. (Note 3) The aforementioned electromagnetic magnet is provided with a rotation-stopping pin. The position of the rotation-preventing pin is at a position away from the fixed shaft. The rotation-preventing pin protrudes from the electromagnetic magnet toward the braking surface, The aforementioned rotation-preventing pin is inserted into a pin hole provided in the movable body, and is part of the elevator brake device as described in Appendix 1 or Appendix 2. (Note 4) An elevator brake device according to any one of the appendices 1 to 3, wherein an elastically deformable elastic member is placed in the gap between the inner surface of the insertion hole and the fixed shaft. (Note 5) The brake device body has a detection switch that detects when the movable body has reached the release completion position where the electromagnetic magnet receives the movable body. The detection switch is positioned away from the magnetic pole centerline in a first reference direction, which is a specific direction perpendicular to the magnetic pole centerline of the electromagnetic magnet. The plurality of springs are arranged in positions asymmetrical with respect to the position of the magnetic pole centerline in the first reference direction, In the first reference direction, at least one of the plurality of springs is positioned as the switch-side spring on the side closer to the detection switch with respect to the position of the magnetic pole center line. In the first reference direction, on the side opposite to the detection switch with respect to the position of the magnetic pole center line, at least one of the plurality of springs corresponding to the switch-side spring is arranged as the anti-switch-side spring. The elevator brake device according to any one of the appendices 1 to 4, wherein the distance in the first reference direction from the position of the spring on the switch side to the position of the magnetic pole center line is greater than the distance in the first reference direction from the position of the spring on the opposite side of the switch to the position of the magnetic pole center line. (Note 6) The brake device body has a detection switch that detects when the movable body has reached the release completion position where the electromagnetic magnet receives the movable body. The detection switch is positioned away from the magnetic pole centerline in a first reference direction, which is a specific direction perpendicular to the magnetic pole centerline of the electromagnetic magnet. The plurality of springs are arranged symmetrically with respect to the position of the magnetic pole centerline in the first reference direction, In the first reference direction, at least one of the plurality of springs is positioned as the switch-side spring on the side closer to the detection switch with respect to the position of the magnetic pole center line. In the first reference direction, on the side opposite to the detection switch with respect to the position of the magnetic pole center line, at least one of the plurality of springs corresponding to the switch-side spring is arranged as the anti-switch-side spring. At least one of the springs on the switch side is a specific spring. An elevator brake device according to any one of the appendices 1 to 4, wherein the spring constant of the specified spring is higher than the spring constant of the other springs. (Note 7) The brake device body has a detection switch that detects when the movable body has reached the release completion position where the electromagnetic magnet receives the movable body. The detection switch is positioned away from the magnetic pole centerline in a first reference direction, which is a specific direction perpendicular to the magnetic pole centerline of the electromagnetic magnet. The plurality of springs are arranged symmetrically with respect to the position of the magnetic pole centerline in the first reference direction, In the first reference direction, at least one of the plurality of springs is positioned as the switch-side spring on the side closer to the detection switch with respect to the position of the magnetic pole center line. In the first reference direction, on the side opposite to the detection switch with respect to the position of the magnetic pole center line, at least one of the plurality of springs corresponding to the switch-side spring is arranged as the anti-switch-side spring. Each of the aforementioned springs is individually inserted into a plurality of fixed-side spring receiving recesses provided in the electromagnetic magnet. Of the plurality of fixed-side spring receiving recesses, at least one of the fixed-side spring receiving recesses into which the switch-side spring is inserted is a specific spring receiving recess. The elevator brake device according to any one of the appendices 1 to 4, wherein the depth dimension of the specified spring support recess is smaller than the depth dimension of the fixed-side spring support recess other than the specified spring support recess. [Explanation of Symbols]

[0130] 11 Brake drum (rotating body), 12 Brake unit (brake device body), 13 Electromagnetic magnet, 14 Movable body, 15 Fixed shaft, 16 Spring, 16a Specific spring, 17 Elastic member, 19 Detection switch, 20 Rotation stopper pin, 111 Braking surface, 136 Fixed side spring receiving recess, 136a Specific spring receiving recess, 143 Insertion hole.

Claims

1. A rotating body provided with a braking surface, A brake device body positioned opposite the braking surface and Equipped with, The brake device body is An electromagnetic magnet fixed at a position away from the aforementioned braking surface, A movable body disposed between the braking surface and the electromagnetic magnet, A fixed shaft is fixed to the electromagnetic magnet and inserted into an insertion hole provided in the movable body, A plurality of springs are arranged around the fixed shaft and generate an elastic restoring force in the direction that brings the movable body into contact with the braking surface. It has, The electromagnetic magnet generates an electromagnetic attractive force that attracts the movable body, thereby moving the movable body away from the braking surface against the elastic restoring force of the plurality of springs. The number of fixed shafts is one. An elevator brake device in which a gap exists between the inner surface of the insertion hole and the fixed shaft.

2. The elevator brake device according to claim 1, wherein, when the electromagnetic magnet is viewed along the axis of the fixed shaft, the four springs are arranged at the four corners of the electromagnetic magnet.

3. The aforementioned electromagnetic magnet is provided with a rotation-stopping pin. The position of the rotation-preventing pin is at a position away from the fixed shaft. The rotation-stopping pin protrudes from the electromagnetic magnet toward the braking surface, The elevator brake device according to claim 1 or claim 2, wherein the rotation-stopping pin is inserted into a pin hole provided in the movable body.

4. An elevator brake device according to claim 1 or claim 2, wherein an elastically deformable elastic member is arranged in the gap between the inner surface of the insertion hole and the fixed shaft.

5. The brake device body has a detection switch that detects when the movable body has reached the release completion position where the electromagnetic magnet receives the movable body. The detection switch is positioned at a location away from the magnetic pole centerline in a first reference direction, which is a specific direction perpendicular to the magnetic pole centerline of the electromagnetic magnet. The plurality of springs are arranged in positions asymmetrical with respect to the position of the magnetic pole centerline in the first reference direction, In the first reference direction, at least one of the plurality of springs is positioned as the switch-side spring on the side closer to the detection switch when viewed from the position of the magnetic pole center line. In the first reference direction, on the side opposite to the detection switch with respect to the position of the magnetic pole center line, at least one of the plurality of springs corresponding to the switch-side spring is arranged as the anti-switch-side spring. The elevator brake device according to claim 1 or claim 2, wherein the distance in the first reference direction from the position of the spring on the switch side to the position of the magnetic pole center line is greater than the distance in the first reference direction from the position of the spring on the opposite side of the switch to the position of the magnetic pole center line.

6. The brake device body has a detection switch that detects when the movable body has reached the release completion position where the electromagnetic magnet receives the movable body. The detection switch is positioned at a location away from the magnetic pole centerline in a first reference direction, which is a specific direction perpendicular to the magnetic pole centerline of the electromagnetic magnet. The plurality of springs are arranged symmetrically with respect to the position of the magnetic pole centerline in the first reference direction, In the first reference direction, at least one of the plurality of springs is positioned as the switch-side spring on the side closer to the detection switch when viewed from the position of the magnetic pole center line. In the first reference direction, on the side opposite to the detection switch with respect to the position of the magnetic pole center line, at least one of the plurality of springs corresponding to the switch-side spring is arranged as the anti-switch-side spring. At least one of the springs on the switch side is a specific spring. The elevator brake device according to claim 1 or claim 2, wherein the spring constant of the specified spring is higher than the spring constant of the other springs.

7. The brake device body has a detection switch that detects when the movable body has reached the release completion position where the electromagnetic magnet receives the movable body. The detection switch is positioned at a location away from the magnetic pole centerline in a first reference direction, which is a specific direction perpendicular to the magnetic pole centerline of the electromagnetic magnet. The plurality of springs are arranged symmetrically with respect to the position of the magnetic pole centerline in the first reference direction, In the first reference direction, at least one of the plurality of springs is positioned as the switch-side spring on the side closer to the detection switch when viewed from the position of the magnetic pole center line. In the first reference direction, on the side opposite to the detection switch with respect to the position of the magnetic pole center line, at least one of the plurality of springs corresponding to the switch-side spring is arranged as the anti-switch-side spring. Each of the aforementioned springs is individually inserted into a plurality of fixed-side spring receiving recesses provided in the electromagnetic magnet. Of the plurality of fixed-side spring receiving recesses, at least one of the fixed-side spring receiving recesses into which the switch-side spring is inserted is a specific spring receiving recess. The elevator brake device according to claim 1 or claim 2, wherein the depth dimension of the specified spring receiving recess is smaller than the depth dimension of the fixed-side spring receiving recess other than the specified spring receiving recess.

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