Method and device for controlling a closing movement of a door of an elevator car in the event of a power failure, door for an elevator car and elevator installation

Abstract

The present invention relates to a method for controlling a closing movement of a door (104) of a lift car (100) during a power failure, wherein, during a control operation of the door (104), electrical power is buffered and, in response to the power failure, the power is provided as backup power (128) to a control device (110) of the door (104) in order to decelerate the closing movement.

Description

[0001] The present invention relates to a method for controlling a closing movement of a door of an elevator car in the event of a power failure, a corresponding device, a method for retrofitting a door of an elevator car, a door for an elevator car and an elevator system.

[0002] An elevator system can have doors that close automatically when the power is off. Each door can have a mechanical energy storage device that is released in the event of a power failure, causing the door to close. For example, the elevator door might have a mechanism, such as a pre-tensioned spring or a tension weight, designed to close the door automatically as soon as it is no longer actively held open by a normally powered actuator.

[0003] The door can close without any braking action. It can accelerate sharply and slam against a door stop. This can result in a loud noise.

[0004] To prevent noise, the door can be equipped with a friction brake. This component, which is not used during normal operation, incurs additional costs. Alternatively, the door's drive motor can be used as a dynamic brake during a power outage by permanently wiring it as a generator. This requires a special design for the drive motor.

[0005] For example, US 2021 / 292129 A1 describes a control unit for an elevator door. JP1992059587A describes a door drive that uses a built-in battery to control the closing movement. JP1999021052A shows a door drive that slows the door movement and reopens it in the event of a power failure.

[0006] Among other things, there may be a need for an improved method for controlling the closing movement of an elevator car door during a power outage. Furthermore, there may be a need for an improved device that can be used within such a method.

[0007] Such a need can be met by a method and a device according to the independent claims. Advantageous embodiments are defined in the dependent claims and described in the description.

[0008] The approach presented here uses an elevator car door drive to brake the closing movement of the car door. The braking force of the door drive is controlled during a power outage to bring the door to a smooth stop. For this purpose, an electrical buffer with control electronics is connected between the power supply of the door drive's control unit and the control unit itself. The buffer is charged as long as the power supply is functioning. If the power supply fails, the buffered energy is released by the control electronics to the control unit in a controlled manner, allowing the door drive to act as a dynamic brake. The door drive's control unit is designed so that, during a power outage, the door drive can essentially rotate freely, and is locked once the power supply is restored.

[0009] The approach presented here allows a door drive of an elevator door to be used cost-effectively and easily as a controllable dynamic brake. The device presented here can generally be retrofitted without further modifications.

[0010] According to a first aspect of the invention, a method for controlling a closing movement of a door of an elevator cabin in the event of a power failure is presented, wherein electrical energy is buffered during normal operation of the door and, in response to the power failure, the energy is provided as substitute energy for a control unit of the door in order to slow down the closing movement.

[0011] According to a second aspect of the invention, a device for controlling a closing movement of at least one door of an elevator car in the event of a power failure is presented, wherein the device is designed to carry out, implement and / or control the method according to the first aspect of the invention in appropriate facilities.

[0012] According to a third aspect of the invention, a door for an elevator cabin is presented, wherein the door has a mechanical closing mechanism for closing the door in the event of a power failure, wherein a device according to the second aspect of the invention is looped into a power line between a power supply of the control unit and the control unit and buffers the electrical energy from the power supply during normal operation.

[0013] According to a fourth aspect of the invention, an elevator system with at least one door according to the fourth aspect of the invention is presented.

[0014] An elevator system can be a passenger transport system. The elevator system can have at least one elevator car with at least one door. The door can be, in particular, a sliding door. The door can be opened and closed by a motorized door drive. As long as the door drive is supplied with electrical energy, it can exert force on the door and open, close, or hold it in place. In the event of a power failure, the door drive, without power, can no longer hold or move the door. The door, now unbraked, can be closed by a closing mechanism. The closing mechanism can have a mechanical energy storage device. The energy storage device can be, for example, a pre-tensioned spring and / or a wound weight. The spring can be tensioned when the door opens. The weight can be pulled upwards during the opening movement. The energy stored in the energy storage device powers a single closing movement of the door.After the closing movement, the amount of energy stored in the energy storage unit is essentially used up.

[0015] The door drive is operated by a control unit. The control unit is powered by an electrical supply. The power supply provides a supply voltage. This supply voltage can be a low voltage, such as 24 volts DC. The control unit uses this supply voltage to power the door drive and operate the door.

[0016] In the approach presented here, the supply voltage for the control unit is buffered in an electrical energy storage device of an intermediate device, according to the second aspect of the invention. The electrical energy storage device can be, for example, a battery and / or a capacitor. If the power fails and consequently the supply voltage is interrupted, the buffered electrical energy is released in a controlled manner by the device's control electronics. The buffered energy can be provided as replacement energy for the control unit's supply voltage. This allows the control unit to continue powering the door drive, and the door drive can control the closing movement driven by the locking mechanism.

[0017] The backup energy will be provided intermittently, meaning it can be supplied with time interruptions. In other words, the backup energy cannot be supplied continuously. During these interruptions, the door can be accelerated by the closing mechanism. While the backup energy is being supplied, the door can be decelerated. This allows the door to close intermittently or gradually. During an interruption, the door can be accelerated to a low speed in response to a force applied by the closing mechanism. When the backup energy is supplied, this low speed can be reduced again.

[0018] Backup power can be provided with a predefined delay after a power outage. This delay allows the door's closing mechanism to accelerate before the backup power is provided, initiating the closing movement. After the delay, the backup power is provided, and the door decelerates. The delay duration can depend on the door design, the closing mechanism, and / or the door drive. For example, the delay duration can be shorter than 5 seconds, shorter than 2 seconds, shorter than 1 second, or shorter than 0.5 seconds. The delay duration can be parameterized, for example, during the commissioning of the elevator system or when retrofitting the device.

[0019] Alternatively or additionally, backup power can be provided when the start of the closing movement is detected. The closing movement can be detected by a sensor. A signal from the sensor can be evaluated. The start of the closing movement can be detected when the door has traveled a minimum distance or reached a minimum speed.

[0020] The provisioning process can be interrupted after a predefined provisioning time. During this time, the door can be decelerated by the door drive to a desired target speed. The door can also be decelerated to a standstill during this time. After the provisioning time, the door can be accelerated again by the closing mechanism. The provisioning time can depend on the control unit. It can also depend on the duration of the control unit's boot process. The control unit can short-circuit the door drive coils during the boot process. This short-circuiting can slow the closing movement. The provisioning time can also depend on the door's mass. The provisioning time can be parameterized, for example, during the commissioning of the elevator system or when retrofitting the device.

[0021] Alternatively or additionally, the provisioning process can be interrupted if deceleration is detected. The closing movement can be detected by a sensor. A signal from the sensor can be evaluated. Deceleration can be detected if the door is moving slower than a target speed.

[0022] Alternatively, the backup power supply can be interrupted if the control unit is detected starting up. The control unit can send its status as a data signal. Once the boot process is complete, the backup power supply can be interrupted again.

[0023] The backup energy can be provided again after a predefined delay following an interruption. During this delay, the closing movement can restart. This delay allows a new cycle of accelerating and decelerating the door to begin. Thanks to the predefined delay and provision time, the closing movement can be controlled without data exchange between the device and the control unit.

[0024] Backup energy can be provided until the buffered energy is depleted. Provisioning and interruption can continue until the energy storage is empty. Provisioning and interruption can also occur when the door is closed.

[0025] The device can have connectors for integrating it into a power line between the control unit's power supply and the control unit itself. The connectors can be configured as a mating plug and socket. The device can be easily inserted into an existing disconnect point between the power supply and the control unit using these connectors. Retrofitting is therefore particularly simple.

[0026] It should be noted that some of the possible features and advantages of the invention are described herein with reference to different embodiments of methods on the one hand and of devices on the other. A person skilled in the art will recognize that the features can be suitably combined, adapted, or exchanged to arrive at further embodiments of the invention.

[0027] The following describes embodiments of the invention with reference to the accompanying drawing, whereby neither the drawing nor the description is to be interpreted as limiting the invention.

[0028] Fig. 1 shows a representation of an elevator system according to an exemplary embodiment.

[0029] The figure is merely schematic and not to scale. Identical reference symbols denote identical or equivalent features.

[0030] Fig. 1 Figure 1 shows a representation of an elevator system 100 according to an exemplary embodiment. The elevator system 100 has at least one elevator car 102. The elevator car 102 has a door 104. The door 104 is driven by a door drive 106. The door drive 106 acts on the door 104 via a cable or belt. The door 104 has two opposing door leaves 108. The cable or belt thus moves the door leaves 108 in opposite directions.

[0031] The door drive 106 is controlled by a control unit 110. The control unit 110 is supplied by a power supply 112 or a power supply unit with a supply voltage 114. The power supply 112 converts alternating current from a power grid into direct current with a low voltage to generate the supply voltage 114. The supply voltage 114 is, for example, 24 volts.

[0032] The control unit 110 powers the door drive 106 using the supply voltage 114. As long as the door drive 106 is powered, it can move or hold the door 104. When the door drive 106 is de-energized, it can no longer exert any force on the door 104.

[0033] In the event of a power failure, the door 104 has a closing mechanism 116. The closing mechanism 116 is coupled to the door 104 and the door drive 106 via a cable or belt. The closing mechanism 116 has a mechanical energy storage device 118. Mechanical energy is stored in the energy storage device 118 to close the door 104 once during a power failure. The energy storage device 118 is implemented here as a spring, but could also be a weight. The energy storage device 118 is charged (tensioned) by the door drive 106 with each opening movement of the door 104 and discharged (released) with each closing movement, thereby assisting the door drive 106. If the door 104 is open and the door drive 106 can no longer exert force on the door 104 due to the power failure, the mechanical energy stored in the energy storage device 118 pulls the door 104 closed.

[0034] In the approach presented here, a device 122 for controlling the closing movement of the door 104 in the event of a power failure is connected in a power line 120 between the power supply 112 and the control unit 110. The device 122 comprises control electronics 124 and an electrical energy storage device 126. The energy storage device 126 can, for example, be designed as a battery and / or capacitor.

[0035] During normal operation of the elevator system 100, electrical energy is stored in the energy storage unit 126. The energy storage unit 126 is therefore charged by the control electronics 124 with the supply voltage 114 during normal operation. During a power outage, the control electronics 124 provides the stored energy as backup energy 128 for the control unit 110.

[0036] In one embodiment, the backup energy 128 is provided in pulses during a power failure, for example, by periodically transmitting current pulses to the control unit 110. While the backup energy 128 is being provided, the control unit 110 energizes the door drive 106, and the door drive 106 opposes the closing movement driven by the locking mechanism 116. This slows down or stops the closing movement. When the backup energy 128 is interrupted, the door drive 106 is no longer energized by the control unit 110. As a result, the door drive 106 can no longer oppose the force of the locking mechanism 116, and the closing movement is again driven by the locking mechanism 116. Subsequently, backup energy 128 is provided again, and the closing movement is slowed down once more.By repeatedly supplying and switching off the backup energy 128, the closing movement can be jerky or impulsive. This can significantly reduce the average speed of the closing movement.

[0037] In one embodiment, the backup energy 128 is not provided immediately after a power failure. A predefined waiting period or delay 130 is observed before the backup energy is initially provided. During this delay 130, the closing movement can begin. After the delay 130, the backup energy 128 is provided, and the control unit 110 can energize the door drive 106, thereby slowing down the closing movement again.

[0038] In one embodiment, the supply of backup energy 128 is interrupted after a predefined supply duration 132. During the supply duration 132, the backup energy 128 is supplied. The supply duration 132 is long enough for the door drive 106 to decelerate the closing movement.

[0039] In one embodiment, the provision time 132 depends on the initialization time of the control unit 110. The control unit 110 requires a moment after receiving the backup energy 128 before the door drive 106 is energized. The provision time 132 can be longer than the initialization time to allow the braking effect of the door drive 106 to take effect.

[0040] In one embodiment, the delay time 130 and the availability time 132 depend on the size or mass of the door 104 and the strength of the closing mechanism 116. The availability time 132 also depends on the braking power of the door drive 106. The delay time 130 and the availability time 132 can differ for different elevator systems 100. If the device 122 is retrofitted, the delay time 130 and the availability time 132 can be parameterized during the retrofit.

[0041] In one embodiment, after the supply is interrupted, a delay period of 130 is again observed before the backup energy 128 is supplied again. This alternating supply and non-supply can continue until the energy buffered in the electrical energy storage device 126 is depleted. This can occur regardless of the position of the door 104.

[0042] The provision and interruption of power can also be controlled. In particular, the movement of the door can be detected and evaluated by sensors. For example, backup power (128V) can be provided when the start of the closing movement is detected. Provision can be interrupted when the braking of the closing movement is detected.

[0043] The provisioning process can also be interrupted when the initialization or startup of control unit 110 is signaled.

[0044] In one embodiment, the device 122 has connectors 134 through which the device 122 is connected to the power line 120. The device 122 is independent of the door 104 and only monitors the supply voltage 114. After the supply voltage 114 drops, the buffered energy is provided as the backup energy 128. Due to the connectors 134, the device 122 can be retrofitted particularly easily to existing elevator systems 100.

[0045] Possible embodiments of the invention are summarized below or presented using slightly different wording.

[0046] A device for installation in an elevator door, an elevator door, an elevator, a method for retrofitting an elevator, and a method for slowly closing a door in the event of a power failure are presented.

[0047] Elevator doors have a mechanism designed to close automatically without further force. This usually involves springs or counterweights. If a power outage occurs while the door is open, the door drive no longer provides the force to hold the door open, and the door slams shut very quickly. This results in a loud bang and can damage the door.

[0048] The approach presented here closes the door slowly if a power outage occurs while the door is open. This is achieved by connecting a device to the door drive's power supply.

[0049] With a functioning power supply, this simply passes the 24 V DC on to the door drive and simultaneously charges a capacitor or a battery.

[0050] In the event of a power failure, the door drive is alternately supplied with 24 V for short periods and then disconnected from the 24 V.

[0051] The slow closing mechanism is achieved by the door drive booting up as soon as it receives power, and then short-circuiting the motor coils. This locks the drive. When the power supply drops again, the motor is released. The door can therefore close a little bit at a time and then stop again. This results in a final, less forceful closing. The appliance can continue operating uninterrupted even after the door has closed.

[0052] The device can be easily retrofitted, as no part of the elevator needs to be modified to accommodate it. In regions prone to frequent power outages, the device can be installed from the outset without requiring any modifications to other components.

[0053] Finally, it should be noted that terms such as "comprising," "encompassing," etc., do not exclude other elements or steps, and terms such as "a" or "an" do not exclude a plurality. Furthermore, it should be noted that features or steps described with reference to one of the above embodiments may also be used in combination with other features or steps of other embodiments described above. Reference numerals in the claims are not to be considered as a limitation.

Claims

1. Method for controlling a closing movement of a door (104) of an elevator car (100) in the event of a power failure, wherein during normal operation of the door (104) is buffered and, in response to the power failure, the energy is provided as replacement energy (128) for a control device (110) of the door (104) in order to slow down the closing movement, characterized in that the replacement energy (128) is provided intermittently.

2. Method according to claim 1, wherein the replacement energy (128) is provided after the power failure delayed by a predefined delay period (130).

3. Method according to claim 1, wherein the replacement energy (128) is provided when a start of the closing movement is detected.

4. Method according to one of the preceding claims, wherein the provision is interrupted after a predefined provision period (132).

5. Method according to any one of claims 1 to 3, wherein the provision is interrupted when deceleration is detected.

6. Method according to one of claims 1 to 3, wherein the provision is interrupted when a start-up of the control unit (110) is detected.

7. Method according to one of claims 4 to 6, wherein the replacement energy (128) is provided again after the interruption with a predefined delay period (130).

8. Method according to one of the preceding claims, wherein the replacement energy (128) is provided until the buffered energy is consumed.

9. Device (122) for controlling a closing movement of a door (104) of an elevator car (100) in the event of a power failure, wherein the device (122) is designed to execute, implement, and / or control the method according to one of the preceding claims in corresponding devices.

10. Device (122) according to claim 9, wherein the device (122) has plug connectors (134) for looping the device (122) into a power line (120) between a power supply (112) of the control device (110) and the control device (110).

11. Door (104) for an elevator car (102), wherein the door (104) has a mechanical closing mechanism (116) for closing the door (104) in the event of a power failure, wherein a device (122) according to one of claims 9 to 10 is connected in a power line (120) between a power supply (112) of a control device (110) of the door (104) and the control device (110) and buffers the electrical energy from the power supply (112) during normal operation.

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