JP2015044654A - Electrically-driven lifting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid conventional problems and open an electromagnetic brake for returning a seated person seating on a wheel chair quickly to a lower stage, because in a lifting drive device having an electric motor as a drive source with an electromagnetic brake attached thereto, in an emergency such as blackout, the electromagnetic brake is opened and a ramp must be returned to the lower stage, but conventionally, in the operation of an opening lever, the operation ability is not good, and when the electromagnetic brake is opened by a remote operation via a wire, the structure is complicated.SOLUTION: A push button switch 37 is operated for switching a power source from a main power source 31 to a standby power source 32 in an emergency such as blackout, then DC9V of the standby power source 32 is raised to DC90V by a pressure rise substrate 38 and is applied to an electromagnetic brake 55b. When the electromagnetic brake 55b is opened by the standby power source 32 for descending a ramp, descent speed is suppressed by an additionally provided centrifugal brake.

Description

  The present invention relates to an electric lifting device for eliminating a level difference that raises and lowers a wheelchair between a lower level side and an upper level side of a level difference using an electric motor as a drive source.

  The following patent document discloses a technique related to a lifting device that is mounted on a lifting platform together with a wheelchair on which a person is seated and moves up and down between steps. This type of lifting device includes a base, a fixed column extending upward from the side of the base, a lifting mechanism built in the fixed column, and a lifting platform supported so as to be movable up and down along the fixed column. With the configuration, by raising and lowering the lifting platform between the upper side and the lower side of the step, it is possible to easily move the wheelchair on which the person is sitting, the caregiver, etc. between the steps.

JP 2008-81231 A JP 2005-219882 A

However, the conventional lifting device has the following problems to be solved. In a level difference canceller for wheelchairs, it is necessary to forcibly lower the elevator to the lower end position in the event of a power failure. In an electric lifting apparatus using an electric motor as a drive source, the electric motor is stopped by an electromagnetic brake attached to the electric motor in a normal state, and the lifting platform is stopped. For this reason, in an emergency such as a power failure, it is necessary to release the electromagnetic brake and lower the lifting platform to the lower end.
Conventionally, as means for releasing the electromagnetic brake, (1) a method of mechanically releasing the electromagnetic brake using a lever, a wire, etc., (2) a standby power source such as a battery or UPS (uninterruptible power supply) is used. A method for releasing the electromagnetic brake, and (3) a method for releasing the electromagnetic brake by applying a voltage boosted using a dry battery to the electromagnetic brake are known.
According to the method (1), it is necessary to operate an opening lever provided on the motor main body, and the method of remote operation using a wire has a problem in that the configuration is complicated and the cost is increased. According to the method (2), there is a problem in that the apparatus is enlarged and the cost is increased. According to the method (3), when the operation is performed several times, the dry battery is consumed and needs to be replaced, and there is a problem that the maintainability is not good.
In addition, when the electromagnetic brake is forcibly released by each of the above methods, the lowering speed of the lifting platform is controlled by controlling the lowering speed of the lifting platform, or by measures such as intermittent activation by a timer (intermittent release of the electromagnetic brake). It is necessary to suppress. However, it is difficult in practice to perform electric control in an emergency such as a power failure because the battery is further consumed.
The present invention has been made in view of the above-described conventional problems. While ensuring operability and maintainability, the electromagnetic brake is forcibly released in an emergency such as a power failure, and the descending speed of the lifting platform is efficiently increased. It aims to be able to suppress.

Said subject is solved by each following invention.
A first invention includes a lifting platform that can be lifted and lowered by mounting a wheelchair, and a lifting drive device that lifts and lowers the lifting platform using an electric motor as a drive source. An electric lifting device equipped with an electromagnetic brake that allows the lowering operation, and has a rechargeable secondary battery as a reserve power source for energizing the electromagnetic brake in an emergency, and the lowering speed of the lifting platform has reached a constant speed It is an electric lifting device equipped with a centrifugal brake that operates only occasionally and suppresses the descending speed of the lifting platform.
According to the first aspect of the invention, in normal times, for example, power is supplied from a commercial AC 100V power source (main power source) to operate the electric motor, and the electromagnetic brake operates to the open side. On the other hand, in an emergency such as a power failure, power is supplied from the standby power source and the electromagnetic brake is operated to the open side. For this reason, in an emergency, the lifting platform is returned to the lower end position without stopping by the electromagnetic brake during the lifting. In addition, when the descending speed of the lifting platform reaches a certain speed in an emergency, the descending speed of the lifting platform is suppressed by the centrifugal brake, so that the lifting platform is returned to the lower end position at an appropriate speed. Since the speed control is performed by a centrifugal brake that does not require a power supply, there is no problem that the spare power supply is consumed as compared with speed control by electrical control or intermittent activation by a timer.
As described above, according to the first invention, since the electromagnetic brake is released by the standby power supply, not by the conventional lever operation or the remote operation by the wire, the operability for releasing the electromagnetic brake in an emergency is provided. And rechargeable secondary batteries are used as a backup power source, so that the electromagnetic brake can be quickly opened in an emergency while ensuring maintainability compared to the conventional replacement configuration, etc. Moreover, the descending speed of the lifting platform when the electromagnetic brake is released can be suppressed to an appropriate speed.
In an emergency, switching between the main power supply and the standby power supply can be performed manually or automatically.

A second invention is an electric lifting apparatus according to the first invention, wherein the voltage of a secondary battery as a standby power supply is boosted and applied to an electromagnetic brake.
According to the second aspect of the invention, the electromagnetic brake can be released with a low-power standby power supply.
A third aspect of the invention relates to the electric lifting apparatus according to the first or second aspect, wherein a DC9V type nickel metal hydride battery is used as the secondary battery, and the secondary battery is boosted to DC90V and applied to the electromagnetic brake. It is.
According to the third invention, in an emergency, the electromagnetic brake is released by the DC 9V standby power source.
According to a fourth aspect of the present invention, in any one of the first to third aspects, the lifting drive device includes a screw shaft mechanism having a screw shaft that is rotated by an electric motor, and the centrifugal brake is integrated with the screw shaft. A brake shoe is spring-biased on a rotating disc and a brake drum is arranged on the outer peripheral side of the brake shoe. In the event of an emergency such as a power failure, the electromagnetic brake is released by the standby power supply, and when the rotational speed of the screw shaft that has entered free rotation reaches a certain speed, the centrifugal brake operates and the elevator platform is lowered. Speed is suppressed. The centrifugal brake has a configuration in which the rotational speed of the screw shaft is suppressed by frictional force generated when the brake shoe is displaced to the outer peripheral side against the spring bias by centrifugal force and is pressed against the brake drum.
According to the fourth invention, after the electromagnetic brake is released by the standby power supply, when the descending speed of the lifting platform reaches a constant speed, the centrifugal brake is activated to suppress the descending speed of the lifting platform, thereby the lifting platform. Is slowly returned to the lower end position at an appropriate speed, after which the wheelchair occupant can leave the platform. Centrifugal brakes have a configuration that suppresses the rotational speed of the screw shaft by friction generated by using the rotational motion of the screw shaft, and is a mechanical configuration that does not require a power source, and suppresses the descending speed of the lifting platform by friction. Therefore, there is no problem of expending the standby power.

It is a front view of the electric lifting apparatus which concerns on embodiment of this invention. This figure has shown the state which the raising / lowering stand raised to the raise end position. It is a front view of a raising / lowering drive device. This figure has shown the state which the raising / lowering stand raised to the raise end position. It is a left view of a raising / lowering drive device. This figure has shown the state which the raising / lowering stand raised to the raise end position. It is a front view of a brake device. It is a top view of a brake device. This figure shows a braking state in which the lining of each brake shoe is pressed against the inner peripheral surface of the brake drum. It is a top view of a brake device. This figure shows a non-braking state in which the lining of each brake shoe is separated from the inner peripheral surface of the brake drum. It is a block diagram of the power supply circuit of an electric lifting apparatus.

Next, an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 to 3, the electric lifting device 1 of the present embodiment is mainly used as a level difference canceling device for lifting and lowering a wheelchair (not shown) between steps (lower stage D1 and upper stage D2). In the following description, the front side of the electric lifting device 1 shown in FIG. 1 is the front side, and the left-right direction is used as a reference when viewed from the front.
The electric lifting device 1 includes a lifting platform 10 on which a wheelchair is mounted, a base frame 20 for installation, a fixed frame 22 extending upward from the base frame 20, and a lifting drive device 50 for lifting the lifting platform 10 up and down. ing.
The lifting platform 10 has a flat plate shape with an area capable of mounting at least one wheelchair, and moves up and down in parallel between the lower stage D1 and the upper stage D2. The base frame 20 is firmly installed by anchor bolts 21 to 21 on the lower stage D1 side. A fixed frame 22 is provided on the rear side of the base frame 20. The fixed frame 22 is provided so as to extend upward from the center in the left-right direction of the base frame 20. An intermediate frame 23 is supported along the fixed frame 22 so as to be movable up and down, and an elevating drive device 50 is attached. The fixed frame 22, the intermediate frame 23, and the lift drive device 50 are covered with a mast cover 5 installed on the lift base 10.

The elevating drive device 50 includes a first elevating mechanism 51 and a second elevating mechanism 52 that operate simultaneously. The first elevating mechanism 51 is a ball screw mechanism and includes a screw shaft 53 and a nut 54. An electric motor 55 as a drive source for rotating the screw shaft 53 about its axis is installed on the upper portion of the intermediate frame 23. The electric motor 55 is a geared motor with a built-in electromagnetic brake 55b and a reduction gear head 55a. The upper end of the screw shaft 53 is coaxially coupled to the output shaft of the gear head 55a. The electric motor 55 is provided with an emergency brake device 60 separately from the internal electromagnetic brake 55b. The brake device 60 will be described later.
The nut 54 meshed with the screw shaft 53 is coupled to the upper end portion of the screw shaft support 56. The screw shaft support 56 is a long pipe material through which the screw shaft 53 can be inserted on the inner peripheral side, and the lower end portion thereof is coupled to the upper surface of the base frame 20. When the screw shaft 53 is rotated about its axis by the electric motor 55, the screw shaft 53 and thus the intermediate frame 23 are moved up and down with respect to the fixed frame 22 through meshing with the nut 54.
The screw shaft support 56 is held in an upright state by an annular holding member 57 attached to the intermediate frame 23. The holding member 57 moves up and down along the screw shaft support 56 as the intermediate frame 23 moves up and down while holding the screw shaft support 56.

The second lifting mechanism 52 is a moving pulley mechanism and includes a moving pulley 58 and a roller chain 59. In the present embodiment, a configuration in which three sets of moving pulley mechanisms are arranged in parallel is provided. As shown in FIGS. 3 and 4, the three movable pulleys 58 to 58 are rotatably supported coaxially with each other via a support shaft provided on the upper portion of the intermediate frame 23. One end side 59 a of the roller chain 59 spanned around each of the three movable pulleys 58 to 58 is coupled to the upper portion of the fixed frame 22. The other end side 59 b of the roller chain 59 that is folded downward through the movable pulley 58 is coupled to the lifting frame 9 of the lifting platform 10.
When the electric motor 55 is activated and the screw shaft 53 rotates around the shaft, the intermediate frame 23 moves up and down. As the intermediate frame 23 moves up and down, the three movable pulleys 58 to 58 are integrally displaced up and down. When the movable pulleys 58 to 58 are displaced up and down, the lifting platform 10 moves up and down with respect to the intermediate frame 23. Therefore, the lifting platform 10 moves up and down with respect to the fixed frame 22 at a speed (double speed) that is the sum of the lifting speed of the intermediate frame 23 with respect to the fixed frame 22 and the moving speed of the movable pulley with respect to the fixed frame 22. Further, the lifting distance of the lifting platform 10 is twice the lifting distance of the intermediate frame 23.
On the front surface of the mast cover 5, a remote controller 3 for mainly performing the lifting operation of the electric lifting device 1 is installed. When the seated person of the wheelchair who got on the lifting platform 10 or the caregiver operates the remote controller 3, the lifting operation of the electric lifting device 1 can be performed.
A bellows type guard 4 that can be vertically expanded and contracted is mounted around the lifting platform 10 (four front, rear, left and right surfaces). The lower end of the guard 4 is coupled to the periphery of the base frame 20. The dust frame and waterproofing measures are taken by always covering the fixed frame 22 and the lifting drive device 50 below the lifting platform 10 with the guard 4 regardless of the lifting position of the lifting platform 10. Further, entry of foreign matter below the elevator 10 is prevented.
Handrail frames 13 and 14 are provided on both front and rear sides of the lifting platform 10. The handrail frames 13 and 14 are each provided in an arch shape straddling between the left side and the right side of the lifting platform 10. Gate bars 15 and 16 are respectively provided at the left boarding gate and the right boarding gate of the lifting platform 10. The left and right gate bars 15 and 16 can be opened and closed by being turned up and down by a person sitting mainly on the wheelchair 2 by operating the operation levers 15 a and 16 a up and down.

A brake device 60 is attached to the upper portion of the gear head 55 a of the electric motor 55. The brake device 60 is a centrifugal brake, and has a function of restricting the lowering operation of the lifting platform 10 at a high speed equal to or higher than a certain speed. Details of the brake device 60 are shown in FIGS.
The brake device 60 has a configuration in which a disc 62 and three brake shoes 63 to 63 each having a brake lining 65 are incorporated in a cylindrical brake drum 61. The brake drum 61 is fixed to the upper surface of the gear head 55a. An upper portion 53 a of the screw shaft 53 of the first elevating mechanism 51 enters the center of the brake drum 61. The upper part 53a of the screw shaft 53 protrudes upward through the inner peripheral hole of the hollow output shaft of the gear head 55a. This protruding portion enters the brake drum 61. In the brake drum 61, a disc 62 is coupled to the upper portion 53a of the screw shaft 53. An upper portion 53 a of the screw shaft 53 is inserted into a boss portion 62 a provided at the center of the upper surface of the disc 62. The output shaft of the gear head 55a, the screw shaft 53, and the disc 62 are integrated for rotation. For this reason, when the electric motor 55 is activated, the screw shaft 53 rotates around its axis, and therefore the disc 62 of the brake device 60 rotates integrally.
Three brake shoes 63 to 63 are attached to the upper surface of the disc 62. The three brake shoes 63 to 63 are supported so as to be rotatable along the surface direction of the disk 62 via support shafts 63a. The three support shafts 63a to 63a are arranged at the three-way positions in the circumferential direction. Therefore, the three brake shoes 63 to 63 are point-symmetric with respect to the rotation center of the disk 62 (the rotation axis of the screw shaft 53). Placed in position.

Brake linings 65 are respectively attached to the outer surfaces of the three brake shoes 63 to 63 and on the side surfaces facing the inner surface of the brake drum 61. Further, the three brake shoes 63 to 63 are urged in a direction in which the brake lining 65 is separated from the inner surface of the brake drum 61 by a tension spring 64 interposed between the boss portions 62a.
Since the centrifugal force acting on the three brake shoes 63 to 63 is small in the state where the descending speed of the lifting platform 10 and the rotational speed of the screw shaft 53 (rotational speed of the disc 62) are equal to or less than a predetermined speed, The brake shoes 63 to 63 are respectively held at positions where the brake lining 65 is separated from the inner surface of the brake drum 61 by the urging force of the tension springs 64 to 64. In this state, the rotation of the screw shaft 53 is not restricted by the brake device 60.
On the other hand, when the descending speed of the lifting platform 10 and the rotational speed of the screw shaft 53 (rotational speed of the disc 62) reach a predetermined speed or higher, the centrifugal force acting on the three brake shoes 63 to 63 becomes large. As a result, the three brake shoes 63 to 63 are displaced radially outward against the tension springs 64 to 64, whereby each brake lining 65 is pressed against the inner peripheral surface of the brake drum 61. A large rotational resistance (braking force) is added to the screw shaft 53 due to frictional resistance generated when the brake linings 65 to 65 of the three brake shoes 63 to 63 are pressed against the inner peripheral surface of the brake drum 61 by centrifugal force. Thus, the lowering operation of the lifting platform 10 is regulated.
In this way, the lowering speed of the lifting platform 10 is prevented from exceeding a certain speed by the brake device 60. According to this, the energization to the electric motor 55 is interrupted by a power failure or the like, and the lowering speed of the lifting platform 10 is regulated by the brake device 60 even when the electromagnetic brake 55b is released as will be described later. Thus, the free fall of the lifting platform 10 is prevented.

FIG. 7 shows a power supply circuit 30 for releasing the electromagnetic brake 55b. The power supply circuit 30 for the electromagnetic brake 55b is separated from the motor power supply circuit (not shown). In the motor power supply circuit, AC200V (3-phase) is supplied to the electric motor 55 from an AC100V (single-phase) power supply via an inverter.
The power supply circuit 30 for the electromagnetic brake 55b includes a commercial AC100V (single phase) as the main power supply 31 and a rechargeable battery (spare battery) as the standby power supply 32. In FIG. 7, the flow of power from the main power supply 31 is indicated by a solid line, and the flow of power from the standby power supply 32 is indicated by a broken line.
The electromagnetic brake 55b operates to the open side when DC90V is applied. When DC90V is no longer applied, the electromagnetic brake 55b operates on the braking side to lock the rotation output of the electric motor 55.
The DC 90V applied to the electromagnetic brake 55b is obtained by full-wave rectifying the AC 100V of the main power supply 31 with the rectifier 33. The DC 90V power obtained from the rectifier 33 is supplied to the electromagnetic brake 55b through the power switch 34. As described above, the electromagnetic brake 55b is released by the power supply indicated by the solid line in FIG. The screw shaft 53 is rotated by the rotational output of the electric motor 55 in a state where the electromagnetic brake 55b is released, and the elevator platform 10 is moved up and down.

The power supply circuit 30 of the electromagnetic brake 55b is provided with an emergency standby power supply 32 in addition to the main power supply 31 for normal use. The reserve power source 32 is a rechargeable DC 9 V type (DC 8.4 V) nickel metal hydride battery. The standby power source 32 is charged by the charger 35 with the power of the main power source 31 during normal use.
For example, when the power supply from the main power supply 31 is interrupted in the event of an emergency such as a power failure, if the push button switch 37 for emergency lowering is pressed, DC9V is supplied from the standby power supply 32 via the charge switch 36. Is done. The supplied DC 9V is boosted to DC 90V by the boosting substrate 38. The boosted DC 90V is applied to the electromagnetic brake 55b via the power switch 34, thereby releasing the electromagnetic brake 55b. The electromagnetic brake 55b is released by supplying DC 90V from the standby power supply 32 instead of the main power supply 31 by the flow of emergency power indicated by the broken line in FIG.
In the event of an emergency such as a power failure, the electromagnetic brake 55b is released by the standby power source 32, whereby the elevator 10 that is in the process of being raised or lowered is returned to the lower end position. In an emergency such as a power failure, in a state where AC200V (three-phase) power is not supplied to the electric motor 55, the elevator 10 starts to descend in a state close to free fall that does not depend on the rotational power of the electric motor 55. The descending speed of the lifting platform 10 becomes excessive. However, when the lowering speed of the lifting platform 10 reaches a constant speed, the brake device 60 described above is activated to suppress the rotational speed of the screw shaft 53, thereby suppressing the lowering speed of the lifting platform 10 to a certain speed or less. Is done. For this reason, the lifting platform 10 is slowly returned to the lower end position, so that the seated person in the wheelchair on the lifting platform 10 can safely return to the lower stage D1.

  According to the electric lifting apparatus 1 of the present embodiment configured as described above, the electric motor 55 with the electromagnetic brake 55b is used as the driving source in the lifting drive apparatus 50, and the electromagnetic brake 55b is operated on the open side. As a power source, a standby power source 32 is provided in addition to the main power source 31 (AC 100V power source) during normal use. When the main power supply 31 is cut off in an emergency such as a power failure, the electromagnetic brake 55b operates to the closed side, so that the lifting platform 10 may stop while moving up or down or on the upper stage D2. In this case, it is necessary to safely return the seated person of the wheelchair mounted on the lifting platform 10 to the lower stage D1 side. In order to realize this, the elevating drive device 50 of the present embodiment includes a standby power source 32 for operating the electromagnetic brake 55b to the open side. Switching from the main power supply 31 to the standby power supply 32 can be performed by pressing the push button switch 37. When the push button switch 37 is pushed and operated, the charge switch 36 is activated and the power of DC 9 V is supplied from the standby power source 32 to the booster substrate 38. In the boosting substrate 38, DC9V is boosted to DC90V. The DC 90V power is applied to the electromagnetic brake 55b via the power switch 34, whereby the electromagnetic brake 55b can be operated to the open side.

In this way, compared to a configuration in which the electromagnetic brake is mechanically released by remote operation using a release lever or wire provided on the conventional electric motor side, the operability is not hindered, and the configuration is not complicated. In an emergency, the electromagnetic brake 55b can be released, whereby the elevator 10 and thus the seated person in the wheelchair can be quickly returned to the lower stage D1 side.
Moreover, when the electromagnetic brake 55b is released by the standby power source 32 in the event of a power failure or the like, the elevator 10 may be lowered at a speed close to natural fall. However, according to the electric elevator 1 of the present embodiment, the elevator 10 There is provided a brake device (centrifugal brake) 60 that operates when the lowering speed of the motor reaches a constant speed faster than the normal use state. For this reason, after the electromagnetic brake 55b is released by the standby power source 32, when the descending speed of the lifting platform 10 reaches a constant speed, the braking device 60 is activated and the descending speed of the lifting platform 10 is suppressed to a certain speed or less. Thereby, the lifting platform 10 can be slowly lowered to the lower stage D1 at an appropriate speed. For this reason, the seated person in the wheelchair is quickly returned to the lower stage D1 side with peace of mind.
As described above, as a means for suppressing the descending speed of the lifting platform 10 in an emergency such as a power failure, the present embodiment includes the brake device 60 that operates when the descending speed of the lifting platform 10 reaches a certain speed. For this reason, the centrifugal brake (brake) of this embodiment is compared with the conventional method of suppressing the descent speed of the elevator 10 by measures such as electrical speed control or intermittent activation (intermittent release of electromagnetic brake) by a timer. In the case of a configuration using the device 60), the power consumption of the standby power supply 32 can be reduced. Since the power of the auxiliary power source 32 can be efficiently spent for maintaining the open state of the electromagnetic brake 55b, the auxiliary power source 32 can be reduced in size and the lifting platform 10 can be reliably returned to the lower stage D1.
In addition, since the standby power source 32 can be charged, the maintainability can be improved while suppressing the cost as compared with the case of replacement.

Various modifications can be made to the embodiment described above. For example, although a nickel metal hydride battery is illustrated as the standby power source 32, a lithium ion battery can also be used.
Further, the standby power supply is not limited to DC 8.4V, and two of them may be connected in series to form a DC 16.8V power supply. In this case, it is sufficient to boost DC 16.8V to DC 90V on the boost substrate.
Furthermore, although the electromagnetic brake 55b opened by DC90V is illustrated, an electromagnetic brake opened by DC45V or DC24V can be used instead. In this case, the booster substrate 38 is used for DC45V or DC24V from DC90V. Can be changed.
Moreover, although the structure which uses AC100V power supply as a main power supply for opening electromagnetic brake 55b was illustrated, even when using the electromagnetic brake which opens AC200V as power supply, by changing rectifier 33 and charger 35, The illustrated emergency power supply countermeasures can be applied.
Furthermore, although the standby power source (secondary battery) that can be charged in the normal use state (when the main power source 31 is used) has been illustrated, it is also possible to use a single-use type battery (dry battery) that cannot be charged as the standby power source.
Further, although the push button switch 37 is exemplified as means for switching from the main power supply 31 to the standby power supply 32, it may be changed to other lever switches or dial switches.
Furthermore, although the structure provided with the 1st and 2nd raising / lowering drive mechanisms 51 and 52 was illustrated as the raising / lowering drive device 50 which raises / lowers the raising / lowering base 10, the form which raises / lowers an elevator by a single raising / lowering drive mechanism is illustrated. The same can be applied to the lifting device.
In addition, although the electric lifting device 1 that lifts and lowers the step between the lower stage D1 and the upper stage D2 by mounting a wheelchair has been illustrated, the emergency reserve illustrated for the lifting device that lifts and lowers articles such as luggage is not limited to a wheelchair. By using the power supply 32 and the brake device 60, the same effect can be obtained.

1 ... Electric lifting device
D1 ... lower stage, D2 ... upper stage 4 ... guard 5 ... mast cover 9 ... lifting platform frame 10 ... lifting platform 13 ... handrail frame (front side)
14 ... handrail frame (rear side)
DESCRIPTION OF SYMBOLS 15 ... Gate bar (left side), 15a ... Operation lever 16 ... Gate bar (right side), 16a operation lever 20 ... Base frame, 21 ... Anchor bolt 22 ... Fixed frame 23 ... Intermediate frame 30 ... Power supply circuit 31 ... Main power supply (AC100V)
32 ... Reserve power supply (DC9V)
33 ... Full-wave rectifier 34 ... Power switch 35 ... Charger 36 ... Charge switch 37 ... Push button switch 38 ... Boosting board 50 ... Lifting drive device 51 ... First lifting mechanism 52 ... Second lifting mechanism 53 ... Screw Shaft, 53a ... Upper 54 ... Nut 55 ... Electric motor, 55a ... Gear head, 55b ... Electromagnetic brake 56 ... Screw shaft support 57 ... Holding member 58 ... Moving pulley 59 ... Roller chain, 59a ... One end side, 59b ... Other end side 60 ... Brake device 61 ... Brake drum 62 ... Disk, 62a ... Boss part 63 ... Brake shoe 64 ... Tension spring 65 ... Brake lining

Claims (4)

A lifting platform that can be moved up and down by mounting a wheelchair, and a lifting drive device that lifts and lowers the lifting platform using an electric motor as a drive source. An electric lifting device with an electromagnetic brake to allow,
A rechargeable secondary battery is provided as a reserve power source for energizing the electromagnetic brake in an emergency, and operates only when the descending speed of the elevator reaches a constant speed to suppress the descending speed of the elevator Electric lifting device with centrifugal brake. 2. The electric lifting apparatus according to claim 1, wherein the voltage of a secondary battery as the reserve power source is boosted and applied to the electromagnetic brake. 3. The electric lifting apparatus according to claim 2, wherein a DC9V type nickel metal hydride battery is used as the secondary battery, and the secondary battery is boosted to DC 90V and applied to the electromagnetic brake. The electric lifting apparatus according to any one of claims 1 to 3, further comprising: a screw shaft mechanism having a screw shaft that is rotated by the electric motor as the lifting drive device; The brake shoe is spring-biased and arranged on a disk that rotates integrally with the screw shaft, and the brake drum is arranged on the outer peripheral side of the brake shoe. The rotational speed of the screw shaft reaches a constant speed. An electric lifting device configured to suppress the rotational speed of the screw shaft by a frictional force generated when the brake shoe is displaced to the outer peripheral side against a spring bias by a centrifugal force and is pressed against the brake drum. .

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