JP5568319B2 - Brake control device for hoisting machine - Google Patents

Description

  The present invention relates to a brake control device for a hoisting machine that controls an electromagnetic brake incorporated in the hoisting machine such as an electric chain block.

  Examples of hoisting machines for moving up and down a load, that is, a suspended load, include an electric chain block and a hoist. The electric chain block drives the sprocket over which the load chain is hung so that the lower hook for hanging the load provided at one end of the load chain moves up and down to raise and lower the load. The other end of the load chain is accommodated in a chain container, that is, a chain bucket, provided in the hoisting machine main body. The hoist drives the drum around which the wire is wound, and moves the lower hook for hanging the load provided at the lower end of the wire up and down to lift and lower the load. Sprockets and drums are driven to rotate by electric motors, and in many hoisting machines, induction motors are used as electric motors.

  Such hoisting machines include a type in which lifting and lowering of a suspended load are performed at a constant speed, and a type in which each speed is changed by an operator's switch operation. In the type in which the speed is changed, as described in Patent Document 1, the electric motor is inverter-controlled in order to change the rotation speed of the electric motor.

JP-A-10-291788

  The hoisting machine main body is equipped with an electromagnetic brake for locking the output shaft of the electric motor. When this electromagnetic brake is operated, the output shaft is locked, and for example, the vertical movement of the suspended load can be stopped under a state where the suspended load is suspended to a predetermined height. The electromagnetic brake has a rotating disk that is a fastened brake disk that is attached to the drive shaft, and a fastening disk that is a fastened brake disk disposed opposite to the rotating disk, and the fastening disk rotates. It moves close to and away from the rotating disk in a restricted state. A spring force is applied to the fastening disk in the direction of being in close contact with the rotating disk by a spring member. In order to separate the fastening disk from the rotating disk, an electromagnet incorporating a coil is arranged adjacent to the fastening disk. As a result, when the coil is energized, the fastening disk is attracted against the spring force and separated from the rotating disk, and the electromagnetic brake is opened. On the other hand, when energization to the coil is stopped, the fastening disk is brought into close contact with the rotating disk by the spring force, the electromagnetic brake is brought into a fastening state, and the main shaft is locked.

  As the electromagnetic brake, a DC electromagnetic brake is used in which a direct current is supplied to the coil. Electric power for the coil is supplied by branching an alternating current supplied from an external power source to the electric motor and rectifying it into a direct current.

  When the hoisting machine is being used for hoisting and lowering the suspended load, the coil continues to be supplied with electric current in order to release the electromagnetic brake. When it is in the state, the temperature of the electromagnetic brake rises. If the applied voltage to the coil is reduced to reduce the temperature rise when the fastening disk is attracted and the electromagnetic brake is held open, the fastening disk in close contact with the rotating disk is separated from the rotating disk. It takes a long time to start releasing the brake.

  If the opening start time becomes longer, it takes time from when the electric motor is energized to move the suspended load until the electromagnetic brake is fully released, and the electric motor is in contact with the rotating disk. Will start rotating. For this reason, there is a problem that the wear of the brake linings provided on the respective disks progresses at an early stage and the durability of the hoisting machine is lowered.

  The objective of this invention is improving the durability of an electromagnetic brake, suppressing the temperature rise of the electromagnetic brake of a winding machine.

The brake control device for a hoist according to the present invention includes an electric motor that drives a rotating body that hoists and lowers a suspended load, and switches the output shaft of the electric motor between a fastening state and a fastening release state. A brake disk connected to the output shaft, a fastening disk that is movable toward and away from the rotary disk, a spring member that applies a spring force to the fastening disk toward the rotary disk, and An electromagnetic brake provided with a coil that attracts the fastening disk in a direction away from the rotating disk when driving the rotating body, and a rectification that rectifies alternating current supplied to the electric motor into direct current and supplies the coil to the coil and the circuit, at the time of braking start, a three-phase alternating current supplied to the electric motor is rectified by the rectifier circuit, the brake attraction state, the three-phase AC And having a rectifying phase switching means for rectifying the single-phase AC currents in the rectifier circuit of the flow. The hoisting machine brake control device according to the present invention is characterized in that half-wave rectification is performed by the rectifier circuit when the brake is activated and in the brake suction state .

  According to the present invention, an alternating current supplied to an electric motor that drives a rotating body for winding and unwinding a suspended load is branched and rectified and supplied to a coil of a direct current electromagnetic brake. By increasing the voltage applied to the coil at the time of starting, and the voltage applied to the coil under the suction state, it is possible to speed up the electromagnetic brake opening start operation. As a result, the operation gap, that is, the operation delay between the electric motor and the electromagnetic brake is eliminated, so that the wear of the brake lining can be reduced and the durability of the electromagnetic brake can be improved. In addition, the durability of the electromagnetic brake can be improved while suppressing the temperature increase of the electromagnetic brake by lowering the voltage applied to the coil under the suction state than when starting up.

It is a front view which shows the electric chain block which is a winding machine as one embodiment of this invention. It is a right view of FIG. It is an expanded sectional view of the winding machine main body shown by FIG. FIG. 4 is an enlarged sectional view showing the electromagnetic brake shown in FIG. 3. FIG. 4 is an enlarged cross-sectional view taken along the line AA of FIG. 3 in a state in which the ratchet wheel of the mechanical brake and the ratchet are disengaged. It is an expanded sectional view which shows the part similar to FIG. 5 in the state which the ratchet wheel and ratchet of the mechanical brake meshed. It is a block diagram which shows the control apparatus which controls the action | operation of an electromagnetic brake. It is a time chart which shows the operation timing of an electromagnetic brake and an electric motor at the time of the hoisting operation and the lowering operation of a suspended load. It is a time chart which shows the input current and output current of a rectifier circuit at the time of starting of an electromagnetic brake, and at the time of attraction | suction.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, the electric chain block as the hoisting machine has a hoisting machine main body 10. The hoisting machine main body 10 has a housing 11, and an upper hook, that is, an upper suspending tool 12 is mounted on the upper portion of the longitudinal center of the housing 11. The hoisting machine main body 10 is suspended by the upper suspending tool 12. Is used in the A sprocket 13 as a rotating body is mounted in the housing 11 as shown by a broken line in FIG. 2 so as to be positioned on the lower side of the upper suspension 12 and is rotatable. A load chain 14 is hung on the sprocket 13. Has been passed. A lower hook, that is, a lower suspension 15 is provided at one end of the load chain 14, and a load, that is, a suspended load is hooked on the lower suspension 15.

  The suspended load hooked on the lower hanging tool 15 by rotating the sprocket 13 is moved up or down. As shown in FIGS. 1 and 2, the housing 11 is attached with a chain container, that is, a chain bucket 16 for accommodating the other end side of the load chain 14, and when the suspended load is wound up, the load chain 14. The other end side of the shaft enters the chain bucket 16, and when the suspended load is lowered, the load chain 14 is fed out from the chain bucket 16. An operation input unit 17 is connected to the hoisting machine main body 10 via a cable 18, and an operator can operate the hoisting switch and the lowering switch provided on the operation input unit 17 to suspend a load. The winding operation and the lowering operation are performed.

  As shown in FIG. 3, the sprocket 13 is fixed to a hollow sprocket shaft 21, and both ends of the sprocket shaft 21 are supported by bearings 22 attached to the housing 11, and the sprocket shaft 21 is placed in the housing 11. It is mounted rotatably. An induction type electric motor 23 is mounted in the housing 11 on one side in the longitudinal direction of the hoisting machine body 10 with respect to the sprocket 13, and an output shaft 24 fixed to the rotor of the electric motor 23 is It protrudes outward from both end faces of the electric motor 23. One protruding end 24 a of the output shaft 24 is rotatably supported by a support plate fixed to the housing 11, that is, a bearing 26 provided on the bracket 25, and an electromagnetic brake 27 is attached to the bracket 25.

  As shown in FIG. 4, the electromagnetic brake 27 has a solenoid case 29 in which a coil 28 is annularly assembled. The solenoid case 29 is attached to the bracket 25 by a plurality of fastening rods 31. Between the bracket 25 and the solenoid case 29, a brake disc, that is, a rotating disc 32 on the fastening side is disposed so as to face the bracket 25. The rotating disc 32 is a protruding end of the output shaft 24 as shown in FIG. It is fixed to the part 24a by fixing means such as a spline. Between the rotating disk 32 and the solenoid case 29, a brake disk on the fastening side, that is, a fastening disk 33, is disposed so as to face the rotating disk 32 and to move toward and away from the rotating disk 32. The fastening rod 31 passes through the through hole 34 formed in the fastening disk 33, and the fastening disk 33 is guided by the fastening rod 31 in a state in which the rotation is restricted by the fastening rod 31 and moves in the axial direction.

  A spring case 35 is provided at the center of the solenoid case 29, and a compression coil spring 36 that applies a spring force in the direction toward the rotating disk 32 to the fastening disk 33 is used as a spring member in the spring case 35. It is installed. As shown in FIG. 4, brake linings 37 a and 37 b are provided on both sides of the rotating disk 32. When the fastening disk 33 is pressed against the rotating disk 32 by the spring force of the compression coil spring 36, the brake lining is provided. The fastening disk 33 and the rotating disk 32 are brought into close contact with the bracket 25 via 37a and 37b, and the output shaft 24 is locked.

  Therefore, in a state where the energization of the coil 28 constituting the electromagnet, that is, the solenoid is stopped, the fastening disk 33 is brought into close contact with the rotating disk 32 via the brake lining 37a by the spring force, and the rotating disk 32 is brake lining. The output shaft 24 is fastened and locked to the bracket 25 via the rotary disk 32, so that the electromagnetic brake 27 is in a fastened state. On the other hand, when the coil 28 is energized, the fastening disk 33 is attracted toward the coil 28 against the spring force by the magnetic force, the fastening disk 33 is separated from the rotating disk 32, and the electromagnetic brake 27 rotates the output shaft 24. Will be open.

  As shown in FIG. 3, the other protruding end 24 b of the output shaft 24 of the electric motor 23 is rotatably supported by a bearing 41 attached to the housing 11, and the output shaft 24 is rotatable inside the sprocket shaft 21. Is coupled to a drive shaft 42 incorporated in the joint via a joint 43. The drive shaft 42 constitutes a part of the output shaft 24, and the tip portion thereof is supported by a bearing 44 attached to the housing 11.

  A reduction shaft 45 is rotatably mounted on the housing 11 in parallel with the drive shaft 42 via a bearing 46, and a small gear 47 provided at the tip of the drive shaft 42 is provided at an end of the reduction shaft 45. It meshes with the large gear 48. The small gear 47 and the large gear 48 form a speed reduction mechanism 49 that decelerates the rotation of the drive shaft 42 and transmits it to the speed reduction shaft 45.

  A mechanical brake 50 is attached to the outside of the sprocket shaft 21. The mechanical brake 50 includes a brake disc 53 in which a cylindrical screw portion 51 and a disc portion 52 provided at one end of the screw portion 51 are integrated. The brake disc 53 is fixed to the sprocket shaft 21 by a fixing means such as a spline provided on the inner peripheral surface of the screw portion 51.

  The mechanical brake 50 can obtain a larger braking torque than the electromagnetic brake 27 that operates by electromagnetic force. By providing this mechanical brake 50 on the sprocket 13 side, that is, on the load side in addition to the electromagnetic brake 27, even if a large load is applied to the sprocket 13, the rotation of the sprocket 13 can be reliably regulated.

  A male screw 54a is formed on the outer peripheral surface of the screw portion 51, and a brake gear 55 having a female screw 54b is screwed to the male screw 54a. The brake gear 55 meshes with a connecting gear 56 provided on the reduction shaft 45, and the output of the drive shaft 42 is transmitted to the brake gear 55 via the reduction shaft 45. The brake gear 55 has a larger diameter than the coupling gear 56, and the rotation of the reduction shaft 45 is decelerated and transmitted to the brake gear 55.

  The end surface of the brake gear 55 faces the disc portion 52, and a ratchet wheel 57 is rotatably mounted between the brake gear 55 and the disc portion 52. The disc portion 52 is provided with a brake lining 58a, and an end surface of the brake gear 55 is provided with a brake lining 58b. The brake gear 55 is relatively engaged with the brake disc 53 in the fastening direction, that is, in the direction approaching the disc portion 52. When rotating, both brake linings 58a and 58b are brought into close contact with the ratchet wheel 57, and the mechanical brake 50 is brought into an engaged state. As a result, the brake disc 53 and the brake gear 55 are fastened via the ratchet wheel 57. On the other hand, when the brake gear 55 rotates relative to the brake disc 53 in the direction in which the engagement is released, that is, in the direction away from the disc portion 52, the engagement between the brake disc 53 and the brake gear 55 is released, and the mechanical brake 50 is released. It becomes.

  As described above, when the brake gear 55 rotates relative to the brake disc 53, the brake gear 55 is screwed to the screw portion 51 of the brake disc 53. It moves in the axial direction between the open positions. The open limit position of the brake gear 55 is regulated by a stopper 59 attached to the tip of the screw portion 51.

  When the electric motor 23 is rotated in the forward direction to perform the hoisting operation of the suspended load, the electromagnetic brake 27 is released, and the output shaft 24 is rotationally driven in the forward direction by the electric motor 23 as indicated by an arrow in FIG. The As a result, the brake gear 55 is driven to rotate in the fastening direction in the same direction as the output shaft 24 via the speed reduction shaft 45, and the brake gear 55 is fastened to the brake disc 53 via the ratchet wheel 57. The sprocket 13 is driven in the hoisting direction by the output shaft 24, and the suspended load suspended from the lower suspension tool 15 is hoisted by the load chain 14 spanned on the sprocket 13.

  5 and 6 are enlarged sectional views taken along line AA in FIG. When the output shaft 24 of the electric motor 23 is driven in the forward rotation direction, the speed reduction shaft 45 is driven to rotate in the winding direction indicated by the arrow U1 in FIG. 5, so that the brake gear 55 is fastened to the brake disc 53 via the ratchet wheel 57. Then, it is rotationally driven in the direction shown by the arrow U2. Thereby, the sprocket 13 is driven in the hoisting direction, and the hoisting operation of the suspended load suspended from the load chain 14 is performed. 5 and 6, the outer diameter lines of the brake gear 55 and the connecting gear 56 are indicated by solid lines, and the pitch lines are indicated by alternate long and short dash lines.

  As shown in FIGS. 5 and 6, a ratchet 60 that meshes with the ratchet wheel 57 is swingably attached to the housing 11, and a tip of the ratchet 60 is arranged on the outer periphery of the ratchet wheel 57 by a spring member (not shown). A spring force is applied in the direction of contact with the surface. When the ratchet wheel 57 rotates in the arrow D2 direction, that is, the lowering direction, the ratchet 60 meshes with the ratchet wheel 57 to prevent the ratchet wheel 57 from rotating in the direction indicated by the arrow D2, as shown in FIG.

  When stopping the vertical movement of the suspended load under the state where the suspended load is suspended by the lower suspension tool 15, the power supply to the electric motor 23 is stopped and the power supply to the electromagnetic brake 27 is stopped to stop the electromagnetic brake. 27 will be in a fastening state. At this time, as shown in FIG. 6, the ratchet wheel 57 meshes with the ratchet wheel 57, and the sprocket shaft 21 is locked. That is, at this time, a rotational force is applied to the sprocket shaft 21 in the lowering direction D2 by the load of the suspended load, but the rotation of the output shaft 24 is stopped by the electromagnetic brake 27, and the ratchet wheel 57 is Since it is in a state of being fastened to the disk portion 52, the rotational force in the lowering direction D2 is applied to the sprocket shaft 21 by the load of the suspended load. Thereby, as shown in FIG. 6, the ratchet 60 meshes with the ratchet wheel 57, the sprocket 13 is locked, and the rotation is restricted. Thus, since the sprocket shaft 21 is locked by the mechanical brake 50, even if the electromagnetic brake 27 is released, the suspended load is prevented from being rolled down.

  On the other hand, when the electric motor 23 is rotated in the reverse direction to perform the hanging load lowering operation, electric power is supplied to the coil 28 to release the electromagnetic brake 27, and the output shaft 24 is rotationally driven in the reverse direction by the electric motor 23. At this time, the output shaft 24 is driven in the lowering direction and the speed reducing shaft 45 is rotationally driven in the lowering direction D <b> 1 with the rotational force applied in the lowering direction applied to the sprocket shaft 21 by the suspended load. . As a result, the brake gear 55 rotates relative to the brake disc 53 in the direction of releasing the engagement, and the mechanical brake 50 is released. Therefore, even if the ratchet 60 is engaged with the ratchet wheel 57 as shown in FIG. 6, the contact between the disc portion 52 and the brake gear 55 with respect to the ratchet wheel 57 is released, and the sprocket shaft 21 is caused by the load of the suspended load. Is driven to rotate in the lowering direction.

  When the rotational speed in the lowering direction applied to the sprocket shaft 21 by the suspended load becomes higher than the rotational speed in the lowering direction of the electric motor 23, the brake gear 55 relatively rotates in the direction in which the ratchet wheel 57 is in close contact with the disk portion 52. become. As a result, as shown in FIG. 6, the sprocket shaft 21 is locked and locked by the ratchet wheel 57 in a state where the ratchet 60 is engaged. Thus, the release operation of the mechanical brake 50 and the braking operation of the mechanical brake 50 due to the load of the suspended load are repeated by the rotation of the electric motor 23 in the lowering direction, and the brake linings 58a and 58b are slid on the ratchet wheel 57. However, the suspended load is unwound while being substantially synchronized with the rotation of the output shaft 24. At the time of the lowering motion, the mechanical brake 50 repeats the releasing operation by the output shaft 24 and the braking operation by the load of the suspended load. Therefore, the output shaft 24 receives a rotational force in the reverse direction by the suspended load, that is, a rotational torque. There is no participation.

  However, when starting the lowering operation, if the ratchet 60 is not engaged with the ratchet wheel 57 as shown in FIG. 5, the ratchet 60 is shown in the ratchet wheel 57 by the lowering operation as shown in FIG. The mechanical brake 50 is not operated until it is engaged with each other, and the output shaft 24 is applied with rotational force in the reverse direction, that is, rotational torque.

  As shown in FIG. 3, this hoisting machine is provided with a mechanical brake 50 in addition to the electromagnetic brake 27. However, the hoisting machine is a small hoisting machine used for hoisting and lowering a relatively light suspended load. In the upper machine, only the electromagnetic brake 27 may be mounted and the mechanical brake 50 may not be mounted.

  FIG. 7 is a block diagram showing a control device for controlling the operation of the electromagnetic brake 27. A power supply 61 for supplying a three-phase alternating current is supplied to the electric motor 23 via a controller 62. The electric motor 23 is an induction type alternating current motor driven by a three-phase alternating current. ing. A signal from the operation input unit 17 is sent to the controller 62, and when the hoisting operation switch provided in the operation input unit 17 is operated by the operator, the hoisting operation of the suspended load is performed. When the operation switch for lowering is operated, the hanging load is lowered. Electric power is supplied in the forward direction to the electric motor 23 during the winding operation, and electric power is supplied in the reverse direction to the electric motor 23 during the lowering operation.

  The electromagnetic brake 27 is operated using the electric power supplied to the electric motor 23. The electromagnetic brake 27 is a DC electromagnetic brake that is operated by a DC current, and a rectifier circuit 63 is connected to the controller 62 in order to rectify the AC current supplied to the electric motor 23 and supply it to the coil 28 of the electromagnetic brake 27. Has been.

  As described above, the electromagnetic brake 27 is set to an open state by supplying electric power to the coil 28 when the lifting operation and the lowering operation of the suspended load are performed. When the voltage applied to the electromagnetic brake 27 is set so that the startup time of the electromagnetic brake 27 is equivalent to the operation timing of the electric motor 23, the coil 28 has a suction state in which the electromagnetic brake 27 continues to suck the fastening disk 33. The amount of heat generated as an excessive voltage increases, and the temperature rise of the electromagnetic brake 27 increases. For this reason, it is necessary to increase the size of the electromagnetic brake 27.

  On the other hand, if the electromagnetic brake 27 is downsized to suppress the applied voltage, the startup time of the electromagnetic brake 27 becomes longer. For this reason, when the electromagnetic brake 27 is started, the release operation of the electromagnetic brake 27 is delayed with respect to the operation of the electric motor 23, and the output shaft 24 of the electric motor 23 rotates while the electromagnetic brake 27 remains in the half brake state. As a result, the wear of the brake linings 37a and 37b proceeds.

  Therefore, when the electromagnetic brake 27 is started, that is, when the fastening disk 33 is separated from the rotating disk 32, the applied voltage at the time of activation is applied to the coil 28. The voltage of the state is increased. This shortens the start-up time and suppresses the heat generation of the coil 28 under the suction state.

  Therefore, as shown in FIG. 7, the rectifier circuit 63 to which the three-phase alternating current is supplied from the controller 62 is converted into direct current by three-phase half-wave rectification when the electromagnetic brake 27 is started and applied to the coil 28. In the suction state, single-phase alternating current out of three-phase alternating current is half-wave rectified and applied to the coil 28. The rectifier circuit 63 has a rectifier circuit having a diode or the like for half-wave rectification, and a timer as a rectification phase switching means for switching between three-phase AC rectification and single-phase AC rectification. When a predetermined time has elapsed after the start-up is completed, the suction state is switched. However, by providing the electromagnetic brake 27 with a switch for detecting the position of the fastening disk 33 as a rectifying phase switching means, when it is detected that the fastening disk 33 is separated from the rotating disk 32 after a predetermined phase switching time t has elapsed. You may make it switch to a suction state.

  FIG. 8 is a time chart showing the operation timing of the electromagnetic brake 27 and the electric motor 23 when the suspended load is wound or lowered. FIG. 9 is a time chart showing the input current and output current of the rectifier circuit 63 when the electromagnetic brake 27 is activated and when it is attracted.

  As shown in FIG. 8, when the hoisting switch or the lowering switch of the operation input unit 17 is operated, electric power is supplied to the electric motor 23 and the electromagnetic brake 27. Thus, the sprocket 13 is driven by the electric motor 23 with the electromagnetic brake 27 being released. When the electromagnetic brake 27 is activated and the fastening disk 33 is separated from the rotating disk 32 against the spring force, the three-phase alternating current is half-wave rectified by the rectifier circuit 63 as shown in FIG. The coil 28 is applied. Next, after the fastening disk 33 is separated from the rotating disk 32, the single-phase AC component is half-wave rectified by the rectifier circuit 63 and applied to the coil 28 as shown in FIG. The phase component to be rectified is switched after the phase switching time t has elapsed by a timer 64 as a rectifying switching means incorporated in the rectifying circuit 63.

  By switching the rectifying component in this way, a voltage higher than that in the attracted state is applied to the electromagnetic brake 27 at the time of activation, and the activation time of the electromagnetic brake 27 can be shortened. On the other hand, under the suction state, the applied voltage is lower than that at the time of activation, and the temperature rise of the coil 28 can be suppressed under the suction state.

  In the embodiment described above, the three-phase alternating current supplied from the power source 61 to the electric motor 23 is half-wave rectified and applied to the coil 28 at the start-up, and a predetermined phase switching is performed by the timer 64 as a rectification switching means after the start-up. When the time t elapses, the single-phase alternating current is half-wave rectified and applied to the coil 28. In this way, a voltage set with a reduced rectification component is applied to the coil 28, and the attracted state is maintained.

  As the rectifier circuit 63, there is a form having a full-wave rectifier circuit and a half-wave rectifier circuit. In such a form, at the time of brake activation, a type in which three-phase alternating current is full-wave rectified and applied to the coil 28, a type in which two-phase components among the three-phase alternating current components are full-wave rectified and applied to the coil 28, There is a type in which a single-phase component is full-wave rectified and applied to the coil 28. In each form, a single-phase alternating current is half-wave rectified and applied to the coil 28 by the half-wave rectifier circuit under the suction state. Which of these forms is selected is selected according to the motor output corresponding to the maximum load of the suspended load in which the hoisting operation or the lowering operation is performed.

  In the form in which the hoisting speed and the lowering speed of the hoisting machine are changed, an inverter is mounted on the control device in order to change the rotational speed of the electric motor 23. In a hoisting machine having an inverter, as indicated by a two-dot chain line in FIG. 8, the electric motor 23 gradually increases the frequency supplied to the electric motor 23 when the electric motor 23 is started up, so that the rotational speed of the output shaft 24 is increased. Is increased. When the rotation of the electric motor 23 is stopped, the rotation of the output shaft 24 is gradually reduced. Thus, as a hoisting machine, there is also a form in which the number of revolutions of the electric motor 23 is changed. In this case, the speeds in the hoisting operation and the lowering operation are not limited to when starting or stopping the motor. Is switched according to the operation of the operation button by the operator.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, the hoisting machine described above is an electric chain block having a sprocket 13 around which a load chain 14 as a rope provided with a lower suspender 15 is suspended, and the present invention is also applied to a hoist. Can do. The hoist has a drum as a rotating body around which a wire as a rope provided with a lower suspender is stretched, and an output shaft of an electric motor for driving the drum is similar to an electric chain block In addition, an electromagnetic brake is provided. The controller for controlling the operation of the electric motor 23 and the electromagnetic brake 27 includes a mode in which the commutation phase is switched by software stored in the ROM and without using the microprocessor. Alternatively, a discrete system having a switching device may be used.

DESCRIPTION OF SYMBOLS 10 ... Hoisting machine main body, 11 ... Housing, 13 ... Sprocket (rotary body), 14 ... Load chain, 15 ... Lower hanging tool, 17 ... Operation input part, 21 ... Sprocket shaft, 23 ... Electric motor, 24 ... Output shaft 27 ... Electromagnetic brake, 28 ... Coil, 32 ... Rotating disc, 33 ... Fastening disc, 36 ... Compression coil spring, 37a, 37b ... Brake lining, 50 ... Mechanical brake, 51 ... Screw portion, 52 ... Disc portion, 53 ... Brake disk, 55 ... brake gear, 57 ... ratchet wheel, 60 ... ratchet, 61 ... power supply, 62 ... controller, 63 ... rectifier circuit, 64 ... timer.

Claims (2)

A hoisting machine brake control device that has an electric motor that drives a rotating body that winds and unloads a suspended load, and switches an output shaft of the electric motor between a fastening state and a fastening release state,
A rotating disk coupled to the output shaft, a fastening disk that is movable toward and away from the rotating disk, a spring member that applies a spring force to the fastening disk toward the rotating disk, and when driving the rotating body An electromagnetic brake having a coil for attracting the fastening disk in a direction away from the rotating disk;
A rectifier circuit that rectifies alternating current supplied to the electric motor into direct current and supplies the direct current to the coil;
Rectification phase switching means for rectifying a three-phase AC current supplied to the electric motor by the rectifier circuit at the time of brake activation and rectifying a single-phase AC current among the three-phase AC currents by the rectifier circuit in the brake suction state brake control device of the hoisting machine, characterized in that it comprises a. The brake control device for a hoisting machine according to claim 1, wherein half-wave rectification is performed by the rectifier circuit when the brake is activated and in the brake suction state .

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