Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
  • B66B5/00—Applications of checking, fault-correcting, or safety devices in elevators
  • B66B5/02—Applications of checking, fault-correcting, or safety devices in elevators responsive to abnormal operating conditions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
  • B66B5/00—Applications of checking, fault-correcting, or safety devices in elevators
  • B66B5/02—Applications of checking, fault-correcting, or safety devices in elevators responsive to abnormal operating conditions
  • B66B5/027—Applications of checking, fault-correcting, or safety devices in elevators responsive to abnormal operating conditions to permit passengers to leave an elevator car in case of failure, e.g. moving the car to a reference floor or unlocking the door

Definitions

• the present invention relates to electric motors and in particular those intended for driving a load, and more particularly but not exclusively those intended for driving an elevator car.
• Electric motors whether used for lifting or driving an elevator car, are generally equipped with one or more brakes with no power, that is to say that the brake blocks the rotation of the rotor in the absence of power supply.
• the brake comprises an armature which is biased in the braking position by an elastic bias, the armature being moved when the brake is energized under the effect of an electromagnet.
• FR 2563642 describes an escalator whose stop is controlled by a comparator measuring the difference between a reference speed signal and a real speed signal, so as to avoid a sudden stop of the escalator.
• EP 1674417 discloses an elevator control device for opening a brake system with no current until the speed reaches a certain threshold, at which point the brakes are then closed, the elevator stops then the brakes are reopened. The sequence is repeated until the arrival on a floor.
• a certain threshold at which point the brakes are then closed, the elevator stops then the brakes are reopened. The sequence is repeated until the arrival on a floor.
• Such a device allows the speed of the cabin to remain below a certain threshold but does not prevent jolts. Indeed, the brakes are either fully closed position or fully open position: this system does not incorporate fine regulation and therefore poses problems of comfort to passengers cabin.
• the present invention aims to further improve a device for controlling at least one current-canceling brake fitted to a rotor, in particular a rotor belonging to an electric motor, and it achieves this by virtue of the fact that the control device comprises a control system for bringing the brake, by controlling its supply, in a state which reduces the friction torque applied, so as to allow sliding and driving of the rotor under the effect of a load, the regulation being effected at least according to a return representative of the speed of the load, so as to maintain the speed of the load below a predefined threshold.
• the movement of the load can be smoothly performed up to for example the arrival to the floor in the case of an elevator car.
• the invention avoids if desired the use of a manual unlocking lever with the associated disadvantages.
• the control system can implement a control of the current and / or the supply voltage of the brake at one or more setpoint values of the speed of the load, in particular when the brake is powered by a rectified voltage from a sinusoidal network or inverter voltage, for example via a controlled rectifier.
• This slaving can include, but not limited to, the addition or deletion of one or more rectifying voltage arches, depending on a difference observed between the speed of the load and the setpoint or values.
• the power supply can also be alternatively via a voltage chopper, the servocontrol then being able to implement a modification of the frequency and / or of the cyclic ratio of the voltage delivered to the (x) brake ( s) as a function of a difference observed between the speed of the load and the setpoint (s).
• the measurement of the speed of the charge can be carried out on the basis of signals produced by at least two inductive sensors, in particular in phase quadrature, matching a frequency to the measured speed, the control system being preferably arranged to determine from the phase shift of the signals from these sensors the direction of rotation of the rotor, the inductive sensors in phase quadrature each preferably delivering a square signal with for example a duty cycle of 50%.
• control device is arranged to take the power supply of the brake or brakes on several sources, for example on a network or on a backup battery, in particular via an inverter.
• the subject of the invention is also a method for controlling the displacement of a load driven by an electric motor comprising a rotor equipped with a break brake. current, using the control device according to the invention, this method comprising the following steps:
• FIG. 1 is a schematic representation of an exemplary control system
• FIG. 2 is a perspective view of an example of a brake motor to which the invention can be applied;
• FIG. 3 is. a block diagram illustrating an example of a regulation loop
• FIG. 4 is a graph showing an example of evolution of the speed as a function of time.
• FIG. 5 illustrates different rectification patterns that can be generated for the supply of the brake or brakes.
• FIG. 1 shows an example of a control device 10 produced according to the invention.
• This control device 10 is associated with an electric motor M equipped with one or more electromagnetic brakes 1 1 with no current, for example at least two brakes as shown.
• One or more sensors 12 can provide information representative of the speed of rotation of the motor shaft M and its direction of rotation.
• the information making it possible to know the speed of the cabin can also be provided by at least one electrical quantity of the motor, in particular the remanent voltage. This can avoid the need for a specific sensor and can increase reliability while reducing the cost of the security device.
• the control device 10 can be arranged to analyze the amplitude of the remanent voltage induced by the rotation of the rotor and the frequency of this voltage and, in case of non-coherence, generate an error signal.
• the control device 10 comprises a regulation system formed of any suitable electronic circuit 13, some of whose functionalities are described below, this electronic circuit 13 being for example directly connected to the (x) brake (s) 11 and the (x) sensor (s) 12.
• the control system is preferably arranged to receive, through an input 15, information A representative of the arrival of the cabin at the evacuation stage and automatically interrupt the supply of the brake or brakes 11 when this information is received. .
• the interruption of the supply of the brake (s) 1 1 is preferentially made so as to avoid jolts, for example by applying a downward current ramp.
• the evacuation stage may be other than those between which the cabin was initially located.
• the evacuation stage may, in particular be a predefined floor, for example the ground floor.
• the control device 10 advantageously comprises a battery (not shown) for supplying the brake or brakes 1 1 in the absence of current on the network.
• the control device 10 may then include, if necessary, a voltage booster device to raise the voltage delivered by the battery to a value compatible with the supply of the brake or brakes 1 January.
• the battery is for example a Pb battery, -NiCd, NiMH, lithium ion or lithium polymer voltage 12 V or 24 V and the lifting device is for example arranged to deliver 200 V continuous.
• motor M has been shown in FIG. 2. Such a motor is described for example in publication FR 2 949 625.
• the motor M which is for example induction or permanent magnets, comprises a rotor which drives a pulley 5 on which elevator cables are mounted.
• the invention is not limited to one type of brake in particular and these are for example only axial brakes as described in the application FR 2 800 528.
• the brakes can still be of different types, for example. example as described in the application FR 2 894 731.
• the motor M comprises an axial service brake 1 1, located at the rear of the engine.
• the service brake 11 at the front of the engine 1, there are two caliper emergency brakes 11 acting on a brake disk 4 of the pulley 5.
• the control device can act on the brake of service and emergency brakes.
• the or each brake 1 1 comprises a movable armature carrying a brake lining, this armature being driven in displacement by an electromagnet and biased into a braking position by elastic biasing, thanks to the use of a or more springs.
• the electromagnet moves the armature against the spring (s), which releases the rotor.
• the brake lining is applied to the braking surface of the rotor, which is thus locked in rotation.
• the regulation system of the control device 10 implements a regulation in which the supply of the brake or brakes 11 is controlled so as to allow a braking surface sliding relative to the brake lining, and a controlled rotation of the rotor.
• the brake lining is not totally removed from the braking surface during this regulation and a contact can be maintained between the brake lining and the braking surface, so as to maintain a certain braking torque while still permitting rotation.
• rotor under the effect of driving the load, for example because of its weight or the presence of a counterweight.
• the power supply of the brake (s) 1 1 can be done by a rectified voltage with a variable number of sinusoidal arches, this makes it possible to avoid the voltage fronts and thus to prevent the possible propagation of an amplification surge.
• the sensors 12 used can be of several types. When the use of two inductive sensors in phase quadrature, the signals of the two sensors are combined to obtain a number of edges per turn for the measurement of the speed V.
• the phase shift signal is used for measuring the direction rotation of the rotor.
• Each sensor 12 delivers for example a square signal of 16 periods per revolution, duty cycle of 50%; the signals of the two sensors 12 are combined to obtain 64 fronts per revolution for the measurement of the speed.
• the rotation speed of the rotor can be measured by other means, in particular using an optical or magnetic Hall effect encoder and / or by using the voltage induced across the phases of the motor.
• the voltage regulation system At the beginning of the regulation (step 20), the voltage regulation system generates a ramp of current to progressively loosen the brakes 11, by monitoring (step 21) the appearance of a first signal representative of a rotation of the rotor, in this case the appearance of a first voltage front of the inductive sensors 12 testifying to the setting in motion of the equipment.
• the control system can for example make the following current ramp at the input of the supply of the brakes 11, generating a rectification pattern consisting of 2 arches on 8 for 2s, then 4 arches on 8 for 2s, 6 arches on 8 for 2s, and a complete recovery thereafter.
• the control system is arranged to increment or decrement the amount of current supplying the brake or brakes 11 as long as the signal representative of the speed V is not in the desired range (step 24), in this case as long as we do not have the number n of edges corresponding to the reference speed VC.
• the rectification pattern applied is preferably one that best distributes the arches temporally. as shown in Figure 5.
• This operation makes it possible to slide the one or more brakes 11 onto the braking surface without opening them, in order to avoid as much as possible the jerking of the on / off sequences produced by the total opening of the brake (s) 1 1 .
• step 28 The sequence stops (step 28) and the current in the brakes 11 is then cut off if an external variable is activated, for example the reception of the information A signaling the arrival on a floor or the return of the normal operation of the elevator, or if there is a number of fronts greater than a predefined number over a sampling period. In the latter case the sequence restarts automatically as soon as there is no more front on the sampling period.
• an external variable for example the reception of the information A signaling the arrival on a floor or the return of the normal operation of the elevator, or if there is a number of fronts greater than a predefined number over a sampling period. In the latter case the sequence restarts automatically as soon as there is no more front on the sampling period.
• the invention can also be applied to other devices than lifts, in particular to other lifting devices such as cranes or forklifts.
• the regulation can be of any type and for example of corrector type PID, or corrector in advance and phase delay.
• the rotor may not be part of an electric motor, being for example simply mounted on bearings and driven indirectly by any driving machine by means of cables or gears, for example.

Landscapes

• Cage And Drive Apparatuses For Elevators (AREA)
• Control Of Ac Motors In General (AREA)
• Braking Arrangements (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (2)

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Citations (5)

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• 2013
  • 2013-04-17 FR FR1353484A patent/FR3004872B1/fr not_active Expired - Fee Related
• 2014
  • 2014-04-10 CN CN201480028754.6A patent/CN105246812B/zh not_active Expired - Fee Related
  • 2014-04-10 EP EP14721982.8A patent/EP2986547A2/fr not_active Withdrawn
  • 2014-04-10 WO PCT/IB2014/060627 patent/WO2014170806A2/fr active Application Filing
  • 2014-04-14 CN CN201420178876.0U patent/CN204342203U/zh not_active Expired - Fee Related

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