Control cabinet and escalator including it

Abstract

This invention discloses an escalator control cabinet, wherein a power supply board is installed in the rear layer of the cabinet along the front-to-back direction, and a main board and a safety board are installed in the front layer spaced apart from the rear layer where the power supply board is located. The power supply board integrates at least a braking system power supply providing braking voltage and sustaining voltage for the braking system, a fixed power supply supplying power to various functional devices of the escalator, and a relay for switching the braking voltage and sustaining voltage, thereby reducing the size of the control cabinet. The power supply functions include conventional power supply and providing signals to various units in the control cabinet. This invention also discloses an escalator including the aforementioned control cabinet. By integrating power supplies with multiple functions and arranging multiple circuit boards in layers, the structure of the escalator control cabinet is made more compact. By providing independent power supplies for safety devices, the safety performance of the safety devices is guaranteed and will not be adversely affected by changes in power supply voltage.

Description

Technical Field

[0001] This invention relates to control cabinets, and more specifically, to control cabinets for use in escalator pits. The invention also relates to escalators including said control cabinets. Background Technology

[0002] The control system of escalators is usually located in the pit, where space is limited, so a more compact control system with a smaller footprint is required.

[0003] The power supply and monitoring systems of escalators largely determine their safety, stability, and emergency response capabilities. Therefore, the safety and stability of existing escalator power supply and monitoring systems still need to be improved. Summary of the Invention

[0004] The purpose of this invention is to eliminate or mitigate the above-mentioned problems.

[0005] According to one aspect of the present invention, a control cabinet is provided for an escalator pit, comprising:

[0006] The cabinet includes the frame, side walls, and back wall;

[0007] Cabinet doors are installed on the cabinet frame and are used to close the cabinet.

[0008] The motherboard is responsible for collecting external signals, detecting the status of the escalator, and distributing output commands to various components of the escalator for normal automatic operation.

[0009] Safety panels are devices used to monitor and control the safety functions of escalators; and

[0010] The power supply board provides power to the escalator's braking system, main board, safety board, and auxiliary functional components.

[0011] The power supply board is installed in the rear layer of the cabinet along the front-to-back direction, while the main board and safety board are installed in the front layer, separated from the rear layer where the power supply board is located. The power supply board integrates at least a braking system power supply that provides braking voltage and sustaining voltage for the braking system, a fixed power supply that supplies power to various functional devices of the escalator, and a relay for switching braking voltage and sustaining voltage, so as to reduce the size of the control cabinet. The power supply functions include traditional power supply and providing signals to various units in the control cabinet.

[0012] Preferably, the fixed power supply only supplies power to important components or safety devices in the control cabinet, and the power board also integrates a power supply for all other auxiliary functions of the escalator besides the aforementioned important components and safety devices.

[0013] Preferably, the power board is separated from the motherboard and safety board by sheet metal parts, and the motherboard and safety board are mounted in front of the sheet metal parts.

[0014] Preferably, the sheet metal part includes an opening through which the lead wires between the power board and the motherboard and the safety board pass to connect them.

[0015] Preferably, the rear wall of the cabinet is removable to facilitate maintenance of the power board.

[0016] Preferably, a fan with an airflow direction parallel to the plane of the layer is provided between the power board and the motherboard and security board.

[0017] Preferably, the power board has dimensions of 220mm × 160mm.

[0018] Preferably, the layer containing the power board may also include an additional brake power board, and the layer containing the main board and safety board may also include an expansion board and a function board to expand the functions of the escalator.

[0019] Preferably, the ground of the chip on the power board is directly connected to the ground of the safety measurement feedback signal resistor to avoid pulling down the holding voltage.

[0020] Preferably, the power board also integrates an auxiliary braking system power supply for powering an additional brake power board.

[0021] Preferably, the relay is configured to switch to a sustaining voltage after the brake voltage of the braking system power supply has been maintained for a first predetermined time.

[0022] Preferably, the power board further includes a voltage detection device configured to detect the brake voltage and, after the brake voltage has been continuously exceeding a second predetermined time, to forcibly reduce the brake voltage to a sustaining voltage or to issue an alarm signal.

[0023] Preferably, the first predetermined time is 1 second, the second predetermined time is 3 seconds, the holding brake voltage is 99V, and the sustaining voltage is 24V.

[0024] Preferably, the power board also includes a safety power-to-ground fault detection device, and the filter used in the detection device has a period of 1ms to avoid interference.

[0025] According to another aspect of the present invention, an escalator is provided, comprising a control cabinet according to any one of the preceding claims.

[0026] According to the present invention, the escalator control cabinet integrates multiple functional power supplies and arranges multiple circuit boards in layers, making the structure of the escalator control cabinet more compact. By setting independent power supplies for safety function devices, the safety performance of the safety function devices is guaranteed and will not be adversely affected by changes in power supply voltage. By adjusting the filter period of the ground fault detection device, interference from interference waves can be avoided and the performance of the ground fault detection device can be improved. By directly connecting the ground of the control chip and the ground of the feedback signal in the braking system power supply, the switching fault of the integrated brake voltage and holding voltage is avoided. Attached Figure Description

[0027] Figure 1 This is an exploded perspective view of an escalator control cabinet according to an embodiment of the present invention.

[0028] Figure 2 It is integrated into Figure 1 The circuit diagram of the power supply and relays for the escalator braking system on the power board shown is shown.

[0029] Figure 3 yes Figure 2 The diagram shows the operating voltage and switching time of the brake system power supply output, including the holding voltage and sustaining voltage.

[0030] Figure 4 It is integrated into Figure 1 A schematic diagram illustrating the functions of the multiple power supplies on the power board shown;

[0031] Figure 5 It is integrated into Figure 1 The circuit diagram of multiple power supplies on the power board shown;

[0032] Figure 6 yes Figure 1 The circuit diagram of the ground monitoring system of the integrated circuit on the power board. Detailed Implementation

[0033] Embodiments of the present invention will now be described with reference to the accompanying drawings. Directional terms used in the description, such as "front-to-back," "forward," "rear," "upper," and "lower," describe the arrangement orientation during use according to the embodiments shown in the drawings. These directional terms are for illustrative purposes only and are not intended to be limiting. The power supply mentioned in this invention includes both conventional power supply and signaling to the various units within the control cabinet.

[0034] Figure 1 This is an exploded perspective view of an escalator control cabinet according to an embodiment of the present invention. In actual use, the escalator control cabinet is arranged in the orientation shown in the view, with the door facing forward and the cabinet erected vertically. From Figure 1As can be seen in the attached drawing, the escalator control cabinet is generally indicated by reference numeral 1, including cabinet body 11 and cabinet door 12. Cabinet body 11 includes a frame located at the front of the cabinet body, side walls located around the sides of the cabinet body, and a rear wall located at the rear of the cabinet body. Cabinet door 12 is installed on the frame of cabinet body 11 and is used to close cabinet body 11.

[0035] The control cabinet 1 contains at least a power board 13, a main board 14, and a safety board 17. To make the structure of the control cabinet 1 more compact, such as... Figure 1 In the embodiment shown, the power board 13 is mounted on the rear layer of the control cabinet 1, located on or in front of the rear wall 19. The main board 14 and the safety board 17 are mounted on the front layer, parallel to the rear wall 19 and in front of the power board 13, arranged in layers and spaced apart from the power board 13. The main board 14 and the safety board 17, or the power board 13, can be held in the control cabinet by supports mounted on the side walls. For ease of maintenance of the power board 13, the rear wall 19 of the control cabinet is removable. The main board 14 and the safety board 17 are located on the same layer, but these layers are not necessarily in the same plane; they may be located in parallel planes with a small distance between them.

[0036] Between the rear layer where the power board 13 is installed and the front layer where the main board 14 and safety board 17 are installed, a sheet metal part 111 can be provided. The main board 14 and safety board 17 can be mounted on the sheet metal part 111, located in front of the sheet metal part 111, so that the sheet metal part isolates the main board 14 and safety board 17 from the power board 13, avoiding electromagnetic interference between the power board 13 and the main board 14 and safety board 17. To facilitate wiring between the power board 13 and the main board 14 and safety board 17, an opening can be provided on the sheet metal part 111. The sheet metal part 111 can be permanently or detachably held on the side wall of the control cabinet.

[0037] The layers on which the power board 13, motherboard 14, and safety board 17 are located are interchangeable. That is, the power board 13 can be arranged on the front layer, and the motherboard 14 and safety board 17 can be arranged on the rear layer. In this embodiment of the present invention, the reason why the power board 13 is arranged on the rear layer and the motherboard 14 and safety board 17 are arranged on the front layer is mainly because the motherboard 14 has many interfaces. In order to facilitate wiring, the motherboard 14 and safety board 17 are arranged on the front layer. The power board 13 has fewer wirings, so the power board can be arranged on the rear layer through the opening on the sheet metal part 111.

[0038] The power board 13 is used to convert 220V AC mains power into various operating voltages suitable for the escalator. During voltage conversion, some energy is converted into heat and dissipated. Moreover, since the power board 13 integrates multiple power supplies, the multiple power supplies dissipate more heat. Therefore, the power board 13 is the main heat source in the control cabinet 1. To prevent the temperature inside the control cabinet 1 from becoming too high and affecting the normal operation of the escalator, a fan needs to be installed inside the control cabinet 1. The fan is preferably located between the power board 13 and the main board 14 and safety board 17, and the airflow direction is parallel to the plane of the layers containing the power board 13, main board 14, and safety board 17, so as to dissipate the heat dissipated by the power board 13, main board 14, and safety board 17 during operation throughout the entire space inside the control cabinet 1.

[0039] According to an embodiment of the present invention, the control cabinet 1 may also be equipped with, in the rear layer where the power board 13 is located, such as Figure 1 The optional additional brake power board 18 shown can be installed in the front layer where the main board 14 and safety board 17 are located, and optional expansion boards and function boards 15, 16 can be installed for the management and control of other functions of the escalator.

[0040] For ease of management and space saving, the power board 13 in this embodiment integrates a braking system power supply, Vbrake. The braking system includes a brake device, which comprises an electromagnet, brake shoes, and a brake wheel. When powered on, the electromagnet generates a magnetic attraction force, causing the brake shoes to open against the biasing force of the biasing element and separate from the brake wheel, thus enabling the escalator to operate normally. When the brake device is de-energized, the electromagnet does not generate a magnetic attraction force, and the brake shoes are biased by the pressure of the biasing element to hold the brake wheel, stopping the escalator. Typically, objects exhibit inertia when moving from rest. Therefore, to overcome this inertia, the opening of the brake device usually requires a larger torque, meaning a higher starting voltage (brake voltage) is needed for the electromagnet. However, the torque required to maintain the brake's open position after it is opened is not as high, meaning a lower holding voltage is needed.

[0041] Figure 3 yes Figure 2 The diagram shows the operating voltage and switching time of the braking system power supply output, including the holding voltage and sustaining voltage. Figure 3As shown, according to this embodiment, the brake voltage is 99V and the sustaining voltage is 24V. If the braking system power supply only provides the brake voltage, a large current will be generated in the electromagnet coil due to the high brake voltage. After prolonged operation, this will generate significant heat, shortening the electromagnet's lifespan and potentially burning out the coil. Furthermore, it consumes more electricity, resulting in higher electricity costs. However, by using a sustaining voltage, which is much lower than the brake voltage, after providing the brake voltage, the brake device can remain open, allowing the escalator to operate normally. This also extends the electromagnet's lifespan, reduces electricity costs, and saves energy.

[0042] In existing escalator control cabinets, the brake voltage and sustaining voltage are provided by separate, non-integrated power supplies, which are switched by separate electromagnetic relays or contactors. As a result, existing escalator control cabinets are large in size, the power supplies are distributed in a dispersed manner, and the electromagnetic relays have significant electromagnetic interference.

[0043] Figure 2 For integration Figure 1 The circuit diagram shown on the power board 13 illustrates the braking system power supply and electronic relays for the escalator braking system, which provide the braking voltage and maintaining voltage. From... Figure 2 As can be seen, the mains power is converted into DC voltage through the rectifier circuit, and the DC voltage is converted into a brake voltage and sustaining voltage of appropriate amplitude through the DC transformer. The output of the brake voltage and sustaining voltage is controlled by the control chip, and the switching of the brake voltage and sustaining voltage is controlled by the electronic relay.

[0044] According to an embodiment of the present invention, the braking system power supply providing the holding voltage and the sustaining voltage, as well as the electronic relay, are integrated on a power supply board of approximately 220mm × 160mm. The braking system power supply and the relay are controlled using a UC2844 chip, thereby greatly reducing the size of the dispersed power supply in the prior art. Moreover, the use of electronic relays also avoids the large electromagnetic interference of separate electromagnetic relays or contactors.

[0045] When the braking system power supply, which provides the holding voltage and sustaining voltage, and the relay are integrated onto such a small circuit board, a switching failure may occur when the relay switches from the holding voltage to the sustaining voltage. Specifically, the holding brake may be released during the switch, causing the escalator to stop and malfunction. Waveform monitoring of the holding voltage, sustaining voltage, and the VCC supply voltage of the UC2844 chip revealed that the holding voltage supply phase pulls down the VCC supply voltage of the UC2844, causing it to malfunction and preventing a proper switch from the holding voltage to the sustaining voltage source.

[0046] Analysis revealed that this was due to a potential difference between the ground of UC2844 and the resistor (not shown in the map, but the same as the ground of Rs) that provides the feedback signal to UC2844. To solve this problem, according to an embodiment of the present invention, the ground of UC2844 is directly connected to the ground of the resistor providing the feedback signal, thereby eliminating the fault.

[0047] Return to reference Figure 3 ,from Figure 3 It can also be seen that in this embodiment, after the braking system power supply provides the braking voltage to the electromagnet for a first predetermined time, the switching device switches to the sustaining voltage. The first predetermined time is 1 second. The first predetermined time can vary according to the properties of the electromagnet itself and the requirements for overheating.

[0048] To ensure that the switching device can properly switch the holding brake voltage to the sustaining voltage, the control cabinet 1 according to the present invention may further include a monitoring device, which monitors... Figure 2 The detection feedback resistor Rs shown extracts the feedback signal to detect the brake voltage and the holding voltage. After the braking system power supply provides the brake voltage for a second predetermined time, the monitoring device checks whether the voltage provided by the braking system power supply is still the brake voltage. If it determines that the detected voltage is still the brake voltage, an alarm mechanism is triggered to remind the operator to perform protective operations, or the monitoring device directly shuts off the braking system power supply, causing the escalator's brake device to be released and the escalator to be braked. This avoids damage to the electromagnet caused by overheating of the brake device due to the operator not being present and failing to manually shut off the brake voltage in time, thereby extending the electromagnet's lifespan. The second predetermined time is longer than the first predetermined time, and the second predetermined time can be, for example, 3 seconds. The second predetermined time needs to take into account the communication delay between the main board and the braking system power supply, as well as the circuit delay (tested to be approximately 130ms). The second predetermined time can also be varied according to the electromagnet's own properties and the requirements for overheating.

[0049] Figure 4 It is integrated into Figure 1 A schematic diagram illustrating the functions of the multiple power supplies on the power board 13 shown. From Figure 4 As can be seen, in addition to integrating the braking system power supply Vbrake, the power board 13 according to this embodiment also integrates a fixed-power 24V power supply according to escalator industry standards, referred to here as safety power supply 24V, or S24V power supply, and a general power supply 24V, or 24V power supply, whose voltage and power can vary slightly. If necessary, the power board can also integrate an auxiliary braking system power supply to power an additional brake power board.

[0050] In existing technology, apart from the power supply to the motor and braking system, the power supply for other functions in escalators is basically provided by a fixed-power 24V power supply as specified in the escalator industry standard. However, this power supply setting has certain problems. When the load on some functions is too large (e.g., a malfunction occurs), it will cause the overall control voltage to drop. However, the power supply for safety-related functional components in escalators, such as grounding protection systems, speed sensors, voltage sensors, safety monitoring devices (collectively referred to as safety function devices), and important components such as the main board, requires a continuous and stable power supply voltage; otherwise, it may lead to safety accidents in escalators.

[0051] Therefore, according to an embodiment of the present invention, the power board 13 also integrates a separate ordinary 24V power supply, which is a non-constant power supply. In the escalator, the safety function device is powered by a fixed power S24V power supply specified by the escalator industry standard, while other additional functions in the escalator, such as lighting devices, display devices, etc., are powered by this ordinary 24V power supply, thereby avoiding the impact on the normal operation of the safety function device caused by large load changes in the circuit.

[0052] from Figure 4 As can be seen, the braking system power supply Vbrate supplies power to the braking system, the safety power supply S24V supplies power to important components such as the main board and safety function devices, while the ordinary power supply 24V supplies power to all other auxiliary function components in the upper and lower pits, including lighting devices, display devices, auxiliary devices, collection plates, etc.

[0053] In this embodiment of the invention, the power supply board 13 integrates the braking system power supply, the safety power supply S24V, and the ordinary power supply 24V onto the power supply board 13, as shown in the circuit diagram below. Figure 5 As shown, the 220V AC mains voltage is rectified by a rectifier circuit, transformed by a transformer, and output through chip control. This provides the necessary power for the braking system, the safety power supply S24V, and the general power supply 24V, making the safety function devices and important components of the escalator more stable and the escalator more efficient.

[0054] According to embodiments of the present invention, the invention is not limited to those described above. The power board 13 may integrate only the braking system power supply, or only the braking system power supply and the general power supply 24V. All of these implementations are within the scope of the present invention.

[0055] Embodiments of the present invention also include a safety power supply S24V ground fault detection device, the circuit diagram of which is shown below. Figure 6 As shown. From Figure 6As can be seen, when the safety power supply S24V and its ground are not shorted to the power supply's PE, no current flows through the optocoupler. However, when the safety power supply S24V is shorted to the power supply's PE, current flows through the output of the safety power supply S24V, through the upper switch, the equivalent resistance of the grounding protection, the optocoupler, and the common terminal to form a loop. The output of the safety power supply S24V then flows through the upper switch and the coupled optocoupler to form a loop. The current is amplified by the optocoupler and output to the detection device. Thus, when the safety power supply S24V is grounded, the detection device can sensitively detect that the safety power supply S24V is grounded. When no signal is detected, a grounding fault is determined. However, in reality, when the safety power supply S24V is not shorted to the power supply's PE, due to system impedance, an interference wave of approximately 100Hz will still be generated before the optocoupler. This means that other components in the power board can easily generate a signal with a cycle period of approximately 10ms, which is very close to the filter period (10ms) of the detection device. Therefore, in order to avoid the detection device mistakenly identifying a ground signal due to interference signals when the safety power supply S24V is not shorted, the detection device in the embodiment of the present invention preferably uses a filter period of 1ms, but other filter periods can also be used, such as 500ms, 2ms, etc., as long as they can be distinguished from interference waves.

[0056] According to the present invention, the escalator control cabinet integrates multiple functional power supplies and arranges multiple circuit boards in layers, making the structure of the escalator control cabinet more compact. By setting independent power supplies for safety function devices, the safety performance of the safety function devices is guaranteed and will not be adversely affected by changes in power supply voltage. By adjusting the filter period of the ground fault detection device, interference from interference waves can be avoided and the performance of the ground fault detection device can be improved. By directly connecting the ground of the control chip and the ground of the feedback signal in the braking system power supply, the switching fault of the integrated brake voltage and holding voltage is avoided.

[0057] The aforementioned escalator control cabinet is typically used with escalators, therefore the present invention also relates to escalators including the aforementioned escalator control cabinet.

[0058] While the best mode for carrying out the invention has been described in detail, those skilled in the art will recognize that there are many alternative designs and implementations for practicing the invention within the scope of the appended claims.

Claims

1. A control cabinet for use in an escalator pit, comprising: The cabinet includes the frame, side walls, and back wall; Cabinet doors are installed on the cabinet frame and are used to close the cabinet. The motherboard is responsible for collecting external signals, detecting the status of the escalator, and distributing output commands to various components of the escalator for normal automatic operation. Safety panel, a device used to monitor and control the safety functions of escalators; and The power supply board provides power to the escalator's braking system, main board, safety board, and auxiliary functional components. The braking system includes a brake device. The power supply board is installed in the rear layer of the cabinet along the front-to-back direction, while the main board and safety board are installed in the front layer, spaced apart from the rear layer where the power supply board is located. The power supply board integrates at least a braking system power supply that provides braking and sustaining voltages to the braking system, a fixed power supply that powers various functional devices of the escalator, and relays for switching braking and sustaining voltages, in order to reduce the size of the control cabinet. The power supply functions include traditional power supply and providing signals to various units in the control cabinet. The power board is separated from the motherboard and safety board by sheet metal parts, with the motherboard and safety board mounted in front of the sheet metal parts. Furthermore, the relay is configured to switch to a sustaining voltage after the brake voltage of the braking system power supply has remained constant for a first predetermined time. The power supply board also includes a voltage detection device configured to detect the brake voltage and, if the brake voltage has remained constant for a second predetermined time, to forcibly reduce the brake voltage to a sustaining voltage or issue an alarm signal. The ground of the chip on the power board is directly connected to the ground of the safety measurement feedback signal resistor to prevent the escalator's brake device from being released during the switch from brake voltage to sustain voltage, thus preventing the escalator from being braked and unable to operate normally.

2. The control cabinet according to claim 1, wherein, The fixed power supply only powers the important components or safety devices in the control cabinet. The power board also integrates a power supply for all other auxiliary functions of the escalator besides the aforementioned important components and safety devices.

3. The control cabinet according to claim 1, wherein, The sheet metal part includes an opening through which the power board, motherboard, and safety board are connected.

4. The control cabinet according to claim 1, wherein, The rear wall of the cabinet is removable for easy maintenance of the power board.

5. The control cabinet according to claim 4, wherein, A fan is provided between the power board and the layers containing the motherboard and security board, with the airflow direction parallel to the plane of the layers.

6. The control cabinet according to claim 5, wherein, The power board measures 220mm × 160mm.

7. The control cabinet according to claim 6, wherein, The layer containing the power board may also include an additional brake power board, and the layer containing the main board and safety board may also include expansion boards and function boards to expand the functionality of the escalator.

8. The control cabinet according to claim 7, wherein, The power board also integrates an auxiliary braking system power supply that powers the additional brake power board.

9. The control cabinet according to claim 1, wherein, The first predetermined time is 1 second, the second predetermined time is 3 seconds, the holding brake voltage is 99V, and the sustaining voltage is 24V.

10. The control cabinet according to claim 9, wherein, The power board also includes a safety power-to-ground fault detection device. The filter used in the detection device has a period of 1ms to avoid interference.

11. An escalator comprising a control cabinet according to any one of the preceding claims.

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