Method and device for controlling a closing movement of a door of a lift car in the event of a power failure, method for retrofitting a door of a lift car, door for a lift car, and lift system

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] Method and device for controlling a closing movement of a door of an elevator car during a power failure, method for retrofitting a door of an elevator car, door for an elevator car, and elevator system

[0002] Description

[0003] 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.

[0004] An elevator system can have doors that close without power. For this purpose, each door can be equipped with a mechanical energy storage device that is released in the event of a power failure and closes the door. For example, a mechanism is provided on the elevator door, e.g., with a preloaded spring or tension weight, designed to automatically close the elevator door as soon as it is no longer actively held open by an actuator that is powered by electricity during normal operation.

[0005] The closing may occur without braking. The door may accelerate sharply and hit a door stop. This can cause a loud noise.

[0006] 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, a door drive motor can be used as a dynamic brake in the event of a power failure by permanently wiring the drive motor as a generator during the power outage. This requires a special design of the drive motor.

[0007] For example, US 2021 / 292129 A1 describes a control device for an elevator door.

[0008] JP1992059587A describes a door drive that controls the closing movement using a built-in battery. JP1999021052A shows a door drive that slows down the door movement and reopens it in the event of a power failure.

[0009] 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 failure. Furthermore, there may be a need for an improved device usable in such a method.

[0010] Such a need can be met by a method and apparatus according to the independent claims. Advantageous embodiments are defined in the dependent claims and described in the description.

[0011] In the approach presented here, a door drive of an elevator car is used to brake the closing movement of a door of the elevator car. The braking power of the door drive is controlled when the door is closed without power in order to bring the door to a gentle stop. For this purpose, an electrical buffer storage device with control electronics is connected between a power supply of a control unit of the door drive and the control unit. The buffer storage device is charged as long as the power supply is functioning. If the power supply fails due to a power failure, the buffered energy is released in a controlled manner by the control electronics to the control unit in order to use the door drive as a dynamic brake. The control unit of the door drive is designed in such a way that if the power supply fails, the door drive can rotate essentially freely and that once the power supply is restored, the door drive is blocked.

[0012] Using the approach presented here, a door drive of an elevator door can be used cost-effectively and easily as a controllable dynamic brake. The device presented here can generally be retrofitted without any further adaptation measures.

[0013] According to a first aspect of the invention, a method for controlling a closing movement of a door of an elevator car 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 backup energy for a control device of the door in order to decelerate the closing movement.

[0014] 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 corresponding devices.

[0015] According to a third aspect of the invention, a method for retrofitting a door of an elevator car is presented, wherein a device according to the second aspect of the invention is looped into a power line between a power supply of the control device and the control device.

[0016] According to a fourth aspect of the invention, a door for an elevator car 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 device and the control device and buffers the electrical energy from the power supply during normal operation.

[0017] According to a fifth aspect of the invention, an elevator system with at least one door according to the fourth aspect of the invention is presented.

[0018] 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 in particular be 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, the door drive can exert force on the door and open, close, or hold the door. In the event of a power failure, the de-energized door drive can no longer hold or move the door. The resulting unbraked door can be closed by a closing mechanism. The closing mechanism can have a mechanical energy storage device. The energy storage device can, for example, be a pre-tensioned spring and / or a wound-up 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 drives a one-time closing movement of the door.After the closing movement, the amount of energy stored in the energy storage device is essentially used up.

[0019] The door drive is operated by a control unit. The control unit is supplied with electrical energy from a power supply. The power supply provides a supply voltage. The supply voltage can be a particularly low voltage, such as 24 volts DC. The control unit uses the supply voltage to power the door drive to operate the door.

[0020] 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 backup energy for the supply voltage of the control unit. This allows the control unit to continue to supply power to the door drive, and the door drive can control the closing movement driven by the locking mechanism.

[0021] The backup energy will be provided intermittently, i.e. the backup energy can be provided with time interruptions. In other words, the backup energy cannot be provided continuously. During the interruptions, the door can be accelerated by the closing mechanism. While the backup energy is provided, the door can be braked. This allows the door to close in bursts or steps. 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 provided, the low speed can be braked again. After the power failure, the backup energy can be provided with a predefined delay.By applying a delay before the backup power is applied, the door can be accelerated by the locking mechanism to begin the closing movement. After the delay period, the backup power is applied and the door is braked. The delay period can depend on the design of the door, the locking mechanism, and / or the door drive. For example, the delay period can be shorter than 5 seconds, shorter than 2 seconds, shorter than 1 second, or shorter than 0.5 seconds. The delay period can be parameterized, for example, during commissioning of the elevator system or when retrofitting the device.

[0022] Alternatively or additionally, backup energy can be provided when the beginning of the closing movement is detected. The closing movement can be recorded by a sensor. A sensor signal can be evaluated. The beginning of the closing movement can be detected when the door has traveled a minimum distance or reached a minimum speed.

[0023] The provisioning can be interrupted after a predefined provisioning time. During a provisioning time, the door can be slowed down by the door drive to a desired target speed. During the provisioning time, the door can also be slowed down to a standstill. After the provisioning time, the door can be accelerated again by the closing mechanism. The provisioning time can depend on the control unit. The provisioning time can depend on the duration of a boot process of the control unit. The control unit can short-circuit the coils of the door drive during the boot process. The short-circuiting can brake the closing movement. The provisioning time can also depend on the ground of the door. The provisioning time can be parameterized, for example, when commissioning the elevator system or when retrofitting the device.

[0024] Alternatively or additionally, the supply can be interrupted if deceleration is detected. The closing movement can be recorded by a sensor. A sensor signal can be evaluated. Deceleration can be detected if the door is slower than a target speed. Alternatively, the 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.

[0025] After the interruption, the backup energy can be re-provided after a predefined delay period. During the delay period, the closing movement can begin again. A new cycle of renewed acceleration and deceleration of the door can begin with the delay period. The predefined delay period and the predefined supply period allow the closing movement to be controlled without data exchange between the device and the control unit.

[0026] Backup energy can be provided until the buffered energy is used up. The provision and interruption of energy can continue until the energy storage is empty. Provision and interruption can also occur when the door is closed.

[0027] The device can have connectors for looping the device into a power line between the control unit's power supply and the control unit. The connectors can be designed as matching plugs and sockets. The connectors allow the device to be easily inserted into an existing separation point between the power supply and the control unit. This makes retrofitting particularly easy.

[0028] 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 devices, on the other. A person skilled in the art will recognize that the features can be combined, adapted, or exchanged as appropriate to achieve further embodiments of the invention. Embodiments of the invention are described below with reference to the accompanying drawings, wherein neither the drawings nor the description are to be construed as limiting the invention.

[0029] Fig. 1 shows a representation of an elevator system according to an embodiment.

[0030] The figure is merely schematic and not to scale. Like reference numerals denote like or equivalent features.

[0031] Fig. 1 shows an illustration 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 here has two opposing door leaves 108. The cable or belt thus moves the door leaves 108 in opposite directions.

[0032] The door drive 106 is controlled by a control unit 110. The control unit 110 is supplied with a supply voltage 114 by a power supply 112 or a power supply unit. 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.

[0033] The control unit 110 energizes the door drive 106 using the supply voltage 114. As long as the door drive 106 is energized, 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.

[0034] 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 the cable or belt. The closing mechanism 116 has a mechanical energy store 118. Mechanical energy is stored in the energy store 118 to close the door 104 once in the event of a power failure. The energy store 118 is designed as a spring here, but can also be designed as a weight. The energy store 118 is charged or tensioned by the door drive 106 with each opening movement of the door 104 and discharged or relaxed with each closing movement, thereby supporting 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 store 118 pulls the door 104 closed with a closing movement.

[0035] 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 looped into 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 be embodied, for example, as an accumulator and / or capacitor.

[0036] Electrical energy is buffered in the energy storage device 126 during normal operation of the elevator system 100. The energy storage device 126 is therefore charged with the supply voltage 114 by the control electronics 124 during normal operation. During a power failure, the control electronics 124 provides the stored energy as backup energy 128 for the control unit 110.

[0037] In one embodiment, the backup energy 128 is provided in pulses during the power failure, for example with current pulses periodically transmitted to the control unit 110. While the backup energy 128 is provided, the control unit 110 energizes the door drive 106, and the door drive 106 counteracts the closing movement driven by the locking mechanism 116. This slows down or stops the closing movement. If the backup energy 128 is interrupted, the control unit 110 no longer supplies the door drive 106 with power. This means that the door drive 106 can no longer counteract 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 again.By repeatedly providing the backup energy 128 and switching it off, the closing movement can be jerky or impulsive. The average speed of the closing movement can thus be significantly reduced. In one exemplary embodiment, the backup energy 128 is not provided immediately after the power failure. Before backup energy is first provided, a predefined waiting period or delay period 130 is waited for. During the delay period 130, the closing movement can begin. After the delay period 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 provision of backup energy 128 is interrupted after a predefined provision period 132. Backup energy 128 is provided during the provision period 132. The provision period 132 is long enough for the door drive 106 to decelerate the closing movement.

[0039] In one embodiment, the provision period 132 depends on an initialization period of the control unit 110. The control unit 110 requires a moment after receiving the backup energy 128 until the door drive 106 is energized. The provision period 132 can be longer than the initialization period so that the braking effect of the door drive 106 can develop.

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

[0041] In one embodiment, after the interruption of the supply, the delay period 130 is again waited for until the backup energy 128 is provided again. This alternation between providing and not providing can continue until the energy buffered in the electrical energy storage device 126 is used up. This can occur independently of the position of the door 104. The provision and interruption can also be carried out in a controlled manner. For this purpose, in particular, a movement of the door can be detected and evaluated by sensors. The backup energy 128 can be provided, for example, when the start of the closing movement is detected. The provision can be interrupted when the deceleration of the closing movement is detected.

[0042] The provision can also be interrupted if the initialization or start-up of the control unit 110 is signaled.

[0043] In one embodiment, the device 122 has connectors 134, via which the device 122 is looped into 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 particularly easily retrofitted to existing elevator systems 100.

[0044] In the following, possible embodiments of the invention are summarized again or presented with slightly different wording.

[0045] 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.

[0046] Elevator doors have a mechanism designed to close the door without any additional force being applied. These mechanisms are usually springs or tension weights. If a power failure occurs while the door is open, the door drive no longer provides the force needed to keep it open, and the door slams shut very quickly. This causes a loud bang and can damage the door.

[0047] The approach presented here allows the door to close slowly if a power failure occurs while the door is open. To do this, a device is looped into the power supply of the door operator. If the power supply is intact, this device simply passes the 24 V DC to the door operator and simultaneously charges a capacitor or battery.

[0048] In the event of a power failure, the door drive is alternately supplied with 24 V for a short time and then disconnected from the 24 V again.

[0049] The slow closing is achieved by the door operator booting up as soon as it is supplied with power and then short-circuiting the motor coils. This blocks the operator. When the power supply drops again, the motor is released again. This allows the door to close a little at a time and then stop again. This allows it to close with less energy at the end. The device can continue to operate smoothly even after closing.

[0050] The device can be easily retrofitted, as no part of the elevator needs to be adapted. In regions with frequent power outages, the device can be installed from the outset without having to adapt other components to accommodate the device.

[0051] Finally, it should be noted that terms such as "having," "comprising," 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 signs in the claims are not to be considered as limitations.

Claims

Patent 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 electrical energy is buffered during normal operation of the door (104) and, in response to the power failure, the energy is provided as substitute energy (128) for a control unit (110) of the door (104) in order to slow down the closing movement, characterized in that the substitute energy (128) is provided intermittently.

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

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 any of the preceding claims, wherein the provisioning is interrupted after a predefined provisioning period (132).

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

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

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

8. Method according to any of the preceding claims, wherein the substitute 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 is trained to execute, implement and / or control the method according to one of the preceding claims in appropriate facilities.

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

11. Method for retrofitting a door (104) of an elevator car (102), wherein a device (122) according to one of claims 9 to 10 is looped into a power line (120) between a power supply (112) of the control unit (110) and the control unit (110).

12. 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 looped into a power line (120) between a power supply (112) of the control unit (110) and the control unit (110) and buffers the electrical energy from the power supply (112) during normal operation.

13. Elevator system (100) with at least one door (104) according to claim 12.

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