Anti-explosion elevator light curtain
By incorporating a power conversion control board and circuit isolation within the explosion-proof enclosure, the safety issues of ordinary light curtains in flammable and explosive environments are resolved, providing a solution for explosion-proof elevator light curtains and ensuring the safe operation of elevators.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHENYANG YINUO TECHNOLOGY CO LTD
- Filing Date
- 2025-03-19
- Publication Date
- 2026-04-21
AI Technical Summary
Existing ordinary light curtains cannot be used safely in flammable and explosive environments, lack explosion-proof performance, and pose potential threats of sparks and electric arcs, creating an urgent market demand.
The explosion-proof enclosure uses a built-in power conversion control board, which includes both intrinsically safe and non-intrinsically safe units. Through an optocoupler-isolated circuit, it converts the voltage to a stable 12-volt voltage to drive the infrared light curtain, ensuring circuit safety. It also generates a switch signal inside the explosion-proof enclosure to control the elevator door.
It has achieved a safe and reliable elevator light curtain in flammable and explosive environments, avoiding the threat of sparks and electric arcs, ensuring the safety of equipment and personnel, and filling the market gap for explosion-proof light curtains.
Smart Images
Figure CN224147476U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of elevator light curtain technology, and in particular relates to an explosion-proof elevator light curtain. Background Technology
[0002] Elevators serve as crucial vertical transportation tools in modern buildings and industrial facilities, with extremely wide applications. Their safe operation is paramount in flammable and explosive environments such as petrochemical, coal mining, and pharmaceutical industries. In these challenging environments, any potential ignition source could lead to catastrophic consequences, thus requiring very high standards for the explosion-proof performance of elevator equipment.
[0003] Optoelectronic equipment plays a crucial role in elevator operation. Light curtains, as safety protection devices for elevator door systems, effectively prevent passengers or objects from being pinched during elevator door closing. However, the ordinary light curtains widely used in the market are only suitable for general locations without flammable or explosive risks. Ordinary light curtains are not designed to fully consider potential hazards such as flammable gases and dust in special environments. Their internal circuitry, optical components, and casing materials cannot meet the safety requirements for use in flammable and explosive locations.
[0004] In flammable and explosive environments, elevator light curtains must not only possess precise sensing capabilities but also ensure that no dangerous factors such as electrical sparks or high temperatures that could trigger an explosion are generated under any circumstances. Currently, despite an urgent market demand for explosion-proof elevator light curtains suitable for such special locations, related products remain unavailable. This situation not only limits the safe use of elevators in special environments but also poses potential safety hazards to related industries. With the continuous development of industry and the increasing emphasis on safety in production, the development of an explosion-proof elevator light curtain suitable for flammable and explosive environments is urgently needed. Summary of the Invention
[0005] This utility model addresses the shortcomings of existing technologies by providing an explosion-proof elevator light curtain.
[0006] To achieve the above objectives, this utility model adopts the following technical solution: an explosion-proof elevator light curtain device, comprising an explosion-proof box, a built-in power conversion control board, and a power input terminal, a signal output terminal, a light curtain connecting cable one, and a light curtain connecting cable two on the box body; wherein, the explosion-proof box is used to house the power conversion control board inside through its explosion-proof function, outputting explosion-proof power to drive the light curtain infrared transmitter and receiver through the light curtain connecting cable one and the light curtain connecting cable two; when the light curtain is blocked, the blocking signal is fed back to the power conversion control board inside the explosion-proof box through the light curtain connecting cable, generating a switching signal and outputting it to the external elevator main control board through the signal output terminal to control the elevator door opening and closing.
[0007] Furthermore, the circuit of the power conversion control board includes a non-intrinsically safe unit, an intrinsically safe unit, and a light curtain unit with drive; wherein the non-intrinsically safe unit is connected to the intrinsically safe unit, and the intrinsically safe unit is connected to the light curtain unit with drive.
[0008] The non-intrinsically safe unit is used to convert 220 volts to 12 volts to supply the intrinsically safe unit.
[0009] The intrinsically safe unit is used to provide an initial turn-on voltage to the optocoupler PC817 through the sampling resistor R2, so that the PC817 turns on and drives the 8050 transistor, which in turn drives the BU406 high-power transistor, turns on the circuit and supplies power to drive the light curtain unit.
[0010] Furthermore, the non-intrinsically safe unit includes an AC220V power input, which is introduced to the input terminal of the transformer via a fuse Fuse1. The transformer is used to convert AC220V to 12V AC power, and the output terminal of the transformer is connected to the rectifier bridge D1, which rectifies the AC power into DC power. The DC output terminal of the rectifier bridge D1 is smoothed by the filter capacitor C3 and then connected to the intrinsically safe unit as the output of the non-intrinsically safe unit.
[0011] Furthermore, the intrinsically safe unit includes a voltage regulator U1, namely LM7812, which is used to provide a stable 12V voltage output.
[0012] The input terminal VIN of voltage regulator U1 is connected to the output V+ of the non-intrinsically safe unit through power transistor Q1, and the ground terminal GND of voltage regulator U1 is connected to the output V- of the non-intrinsically safe unit.
[0013] The input terminal VIN of the voltage regulator U1 is connected to the emitter of the power transistor Q1, the base of the power transistor Q1 is connected to the emitter of the transistor Q2, and the collector of the power transistor Q1 is connected to the output V+ of the non-intrinsically safe unit.
[0014] The collector of transistor Q2 is connected to the output of the non-intrinsically safe unit (specifically, connected to one end of capacitor C4), and the base of transistor Q2 is connected to the phototransistor side of optocoupler PC817. That is, the base of transistor Q2 is connected to the emitter terminal of the phototransistor side, and the collector terminal of the phototransistor side is connected to the collector of transistor Q2 through resistor R1.
[0015] The positive terminal of the diode on the diode side of the optocoupler PC817 is connected to the ground terminal of the voltage regulator U1. The negative terminal of the diode on the diode side is divided into two branches. One branch is connected to the first terminal of the capacitor C4 through the resistor R2. The second terminal of the capacitor C4 is connected to the ground terminal of the voltage regulator U1. The first terminal of the capacitor C4 is also connected to the resistor R1. The other branch is connected to the output terminal Vout of the voltage regulator U1 through a resistor. The optocoupler PC817 is used to isolate non-intrinsically safe and intrinsically safe units.
[0016] Furthermore, four Zener diodes D2, D3, D4, and D5 are connected in parallel between the output terminal Vout of the voltage regulator U1 and the ground terminal of the voltage regulator U1 for current limiting and voltage limiting.
[0017] Furthermore, an LED branch is connected between the output terminal Vout of the voltage regulator U1 and the ground terminal of the voltage regulator U1. This LED branch includes LEDs connected in series and a 2K current-limiting resistor.
[0018] Furthermore, the light curtain unit includes a transistor Q7. The base of transistor Q7 (2N3904) is connected to the output of an infrared receiver tube, which is used to detect whether an object is blocking the light. The infrared receiver tube outputs a signal to the base of transistor Q7 (2N3904) after detecting that an object has passed through it. The collector of transistor Q7 is connected to the control terminal of relay K2. When an object blocks the light, the output signal of the photoelectric sensor will trigger transistor Q7 to conduct, thereby energizing the coil of relay K2. The contacts or auxiliary contacts of relay K2 will act as a signal output terminal connected to the external elevator main control board to control the opening and closing of the elevator doors.
[0019] Compared with the prior art, this utility model has the following advantages.
[0020] This novel explosion-proof elevator light curtain can be used in flammable and explosive environments, offering both safety and reliability. It not only fills the market gap for explosion-proof elevator light curtains but also provides a novel safety solution for flammable and explosive locations. By placing the power conversion control board inside an explosion-proof enclosure, it effectively prevents any potential sparks or arcs from threatening the surrounding environment. This not only ensures the safety of the equipment but also protects personnel and facilities working in hazardous environments. Attached Figure Description
[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The scope of protection of the present invention is not limited to the following description.
[0022] Figure 1 This is a schematic diagram of the overall structure of the explosion-proof elevator light curtain device.
[0023] Figure 2 This is the circuit diagram of the power conversion control board.
[0024] Figure 3 yes Figure 2 Enlarged view of a part Figure 1 .
[0025] Figure 4 yes Figure 2 Enlarged view of a part Figure 2 .
[0026] Figure 5 yes Figure 2 Enlarged view of a part Figure 3 . Detailed Implementation
[0027] To make the objectives, technical solutions, and beneficial effects of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.
[0028] like Figure 1-5 As shown in the specific embodiment: the explosion-proof elevator light curtain device includes an explosion-proof box 1, which houses a power conversion control board. The explosion-proof box 1 has a power input terminal 2, a signal output terminal 3, a light curtain connecting cable 1 (first type) 4, and a light curtain connecting cable 2 (second type) 5. The explosion-proof box 1 is used to house the power conversion control board inside through its explosion-proof function, outputting explosion-proof power to drive the light curtain infrared transmitter 6 and the light curtain infrared receiver 7 through the light curtain connecting cable 1 (first type) and the light curtain connecting cable 2 (second type) 5. The light curtain connecting cable 1 (first type) is connected to the light curtain infrared transmitter 6, and the light curtain connecting cable 2 (second type) is connected to the light curtain infrared receiver 7.
[0029] When the light curtain is blocked, the blocking signal is fed back to the power conversion control board inside the explosion-proof box 1 through the light curtain connection cable, generating a switch signal and outputting it to the external elevator main control board through the signal output terminal 3 to control the elevator door opening and closing.
[0030] Preferably, the circuit of the power conversion control board includes a non-intrinsically safe unit 8, an intrinsically safe unit 9, and a light curtain unit 10 with driving capability; wherein, the non-intrinsically safe unit 8 is connected to the intrinsically safe unit 9, and the intrinsically safe unit 9 is connected to the light curtain unit 10 with driving capability; the non-intrinsically safe unit 8 is used to convert 220 volts to 12 volts to supply the intrinsically safe unit 9; the intrinsically safe unit 9 is used to provide an initial turn-on voltage to the optocoupler PC817 through the sampling resistor R2, so that the PC817 turns on and drives the 8050 transistor, which in turn drives the BU406 high-power transistor, so that the circuit turns on and supplies power to the light curtain unit 10 with driving capability.
[0031] Preferably, the non-intrinsically safe unit 8 includes an AC220V power input, which is introduced to the input terminal of the transformer via a fuse Fuse1. The transformer is used to convert AC220V to 12V AC power, and the output terminal of the transformer is connected to the rectifier bridge D1, which rectifies the AC power into DC power. The DC output terminal of the rectifier bridge D1 is smoothed by the filter capacitor C3 and then connected to the intrinsically safe unit 9 as the output of the non-intrinsically safe unit 8.
[0032] Preferably, the intrinsically safe unit 9 includes a voltage regulator U1 (LM7812) for providing a stable 12V voltage output. The input terminal VIN of the voltage regulator U1 is connected to the output V+ of the non-intrinsically safe unit 8 via a power transistor Q1, and the ground terminal GND of the voltage regulator U1 is connected to the output V- of the non-intrinsically safe unit 8. The input terminal VIN of the voltage regulator U1 is connected to the emitter of the power transistor Q1, the base of the power transistor Q1 is connected to the emitter of the transistor Q2, and the collector of the power transistor Q1 is connected to the output V+ of the non-intrinsically safe unit 8. The collector of transistor Q2 is connected to the output of the non-intrinsically safe unit 8 (specifically, connected to one end of capacitor C4). The base of transistor Q2 is connected to the phototransistor side of optocoupler PC817, that is, the base of transistor Q2 is connected to the emitter terminal of the phototransistor side. The collector terminal of the phototransistor side is connected to the collector of transistor Q2 through resistor R1. The positive terminal of the diode side of optocoupler PC817 is connected to the ground terminal of voltage regulator U1. The negative terminal of the diode side is divided into two branches. One branch is connected to the first terminal of capacitor C4 through resistor R2. The second terminal of capacitor C4 is connected to the ground terminal of voltage regulator U1. The first terminal of capacitor C4 is also connected to resistor R1. The other branch is connected to the output terminal Vout of voltage regulator U1 through a resistor. Optocoupler PC817 is used to isolate the non-intrinsically safe unit and the intrinsically safe unit.
[0033] Preferably, four Zener diodes D2, D3, D4, and D5 are connected in parallel between the output terminal Vout of the voltage regulator U1 and the ground terminal of the voltage regulator U1 for current limiting and voltage limiting. That is, the intrinsically safe circuit 9 uses the four Zener diodes D2, D3, D4, and D5 to regulate the circuit output voltage, so as to achieve the intrinsic safety function of limiting current and voltage.
[0034] Preferably, an LED branch is connected between the output terminal Vout of the voltage regulator U1 and the ground terminal of the voltage regulator U1. The LED branch includes LEDs connected in series and a 2K current-limiting resistor.
[0035] Preferably, the light curtain unit 10 includes an infrared emitting tube and an infrared receiving tube for detecting whether an object is blocking the light. The infrared receiving tube outputs a signal to the base of transistor Q7 (2N3904) after detecting that an object has passed through. The collector of transistor Q7 is connected to the control terminal of relay K2. When an object blocks the light, the output signal of the photoelectric sensor will trigger transistor Q7 to conduct, thereby energizing the coil of relay K2. The contacts or auxiliary contacts of relay K2 will act and be connected to the external elevator main control board as signal output terminal 3 to control the opening and closing of the elevator doors.
[0036] The working principle is as follows: The emitting part of the light curtain consists of multiple infrared emitting tubes connected in series. Similarly, the receiving part consists of multiple infrared receiving tubes connected in series. When there is no obstruction between the emitting and receiving tubes, the infrared receiving tubes are conductive and the relays are closed. When there is an obstruction between the emitting and receiving tubes, the infrared receiving tubes do not receive a light signal and are open, causing the relays to open. This causes the relays to open and close repeatedly with the obstruction, thus controlling the opening and closing of the door.
[0037] The working principle of the power conversion control board circuit is as follows: it consists of a non-intrinsically safe unit 8, an intrinsically safe unit 9, and a light curtain unit 10. The non-intrinsically safe unit 8 converts 220V to 12V to supply the intrinsically safe unit (9). The intrinsically safe unit provides an initial conduction voltage to the optocoupler PC817 through resistor R2, causing PC817 to conduct and drive the 8050 transistor, which in turn drives the BU406 high-power transistor, thus turning on the circuit to supply power to the light curtain unit 10. When an overload or short circuit occurs in the load section at the back end of the BU406 circuit, the voltage at the back end of R2 will be immediately pulled down, causing PC817 to lose its conduction voltage and cut off, thus turning off the 8050 transistor and stopping the circuit from supplying power to the back end, thereby achieving the purpose of limiting current overload. The circuit uses four 13V Zener diodes D2, D3, D4, and D5 to regulate the circuit voltage, thereby achieving the intrinsic safety function of limiting current and voltage.
[0038] When an obstacle blocks the transmitting and receiving parts of the infrared light curtain, the infrared light curtain generates an obstruction signal. This signal is transmitted through the light curtain connecting cable to the power conversion control board inside the explosion-proof box 1, generating a switching signal. The signal is then output through signal output terminal 3 to the elevator main control board to control the elevator door opening and closing, thus achieving both explosion-proof and elevator light curtain functions. This fills the gap in the current situation where only ordinary elevator light curtains are available, and explosion-proof elevator light curtains are not available.
[0039] Specifically, this invention achieves explosion-proof protection by installing an intrinsically safe power supply board inside the explosion-proof box 1. The intrinsically safe power supply is then used to drive the infrared elevator light curtain, thus achieving the function of a light curtain. The infrared emitting and receiving sections of the explosion-proof elevator light curtain can be either ordinary elevator light curtain strips or intrinsically safe elevator light curtain strips. The intrinsically safe unit uses an optocoupler PC817 and a sampling resistor R2 to control current overload.
[0040] This novel explosion-proof elevator light curtain device effectively prevents any potential sparks or arcs from threatening the surrounding environment by placing the power conversion control board inside an explosion-proof enclosure. This ensures equipment safety and provides protection for personnel and facilities working in hazardous environments. Furthermore, the explosion-proof enclosure is equipped with a power input terminal, a signal output terminal, and a cable interface for connecting the light curtain, offering convenience and stability, making installation and maintenance easier.
[0041] This invention employs separation and isolation measures between the intrinsically safe unit, the intrinsically safe unit, and the associated drive light curtain unit. In particular, the use of an optocoupler PC817 achieves electrical isolation between the intrinsically safe and non-intrinsically safe units, enhancing the overall safety performance of the system. Simultaneously, the non-intrinsically safe unit can convert the common 220V AC voltage to 12V DC voltage and supply it to the intrinsically safe unit, ensuring the stable operation of the entire system. The application of the voltage regulator LM7812 further guarantees the stability and reliability of the power supply, maintaining good operating performance even under conditions of large voltage fluctuations.
[0042] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "preferred embodiment," "detailed description," or "preferred embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0043] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Therefore, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope defined by the claims of this utility model.
Claims
1. An explosion-proof elevator light curtain comprising an explosion-proof box (1), characterized in that: The explosion-proof box (1) has a built-in power conversion control board, and the explosion-proof box (1) is provided with a power input terminal (2), a signal output terminal (3), a light curtain connection cable one (4), and a light curtain connection cable two (5); among which, The explosion-proof box (1) is used to house the power conversion control board inside through its explosion-proof function, output explosion-proof power and drive the light curtain infrared transmitter (6) and light curtain infrared receiver (7) through the first light curtain connecting cable (4) and the second light curtain connecting cable (5); when the light curtain is blocked, the blocking signal is fed back to the power conversion control board inside the explosion-proof box (1) through the light curtain connecting cable, generating a switch signal and outputting it to the external elevator main control board through the signal output terminal (3) to control the opening and closing of the elevator door.
2. An explosion-proof elevator light curtain according to claim 1, characterized in that: The circuit of the power conversion control board includes a non-intrinsically safe unit (8), an intrinsically safe unit (9), and a light curtain unit (10) with drive; wherein, the non-intrinsically safe unit (8) is connected to the intrinsically safe unit (9), and the intrinsically safe unit (9) is connected to the light curtain unit (10) with drive. The non-intrinsically safe unit (8) is used to convert 220 volts to 12 volts to supply the intrinsically safe unit (9). The intrinsically safe unit (9) is used to provide an initial turn-on voltage to the optocoupler PC817 through the sampling resistor R2, so that PC817 turns on and drives the 8050 transistor, which in turn drives the BU406 high-power transistor, so that the circuit turns on and supplies power to drive the light curtain unit (10).
3. An explosion-proof elevator light curtain according to claim 2, characterized in that: The non-intrinsically safe unit (8) includes an AC220V power input, which is introduced to the input terminal of the transformer through the fuse Fuse1. The transformer is used to convert AC220V to 12V AC power, and the output terminal of the transformer is connected to the rectifier bridge D1. The DC power is rectified into DC power through the rectifier bridge D1. After being smoothed by the filter capacitor C3, the DC output terminal of the rectifier bridge D1 is used as the output of the non-intrinsically safe unit (8) and connected to the intrinsically safe unit (9).
4. An explosion-proof elevator light curtain according to claim 3, characterized in that: The intrinsically safe unit (9) includes a voltage regulator U1, which is used to provide a stable 12V voltage output; The input terminal V of voltage regulator U1 IN The power transistor Q1 is connected to the output V+ of the non-intrinsically safe unit (8), and the ground terminal GND of the voltage regulator U1 is connected to the output V- of the non-intrinsically safe unit (8). The input terminal V of voltage regulator U1 IN The base of power transistor Q1 is connected to the emitter of transistor Q2, and the collector of power transistor Q1 is connected to the output V+ of the non-intrinsically safe unit (8). The collector of transistor Q2 is connected to the output of the non-intrinsically safe unit (8), and the base of transistor Q2 is connected to the phototransistor side of optocoupler PC817. That is, the base of transistor Q2 is connected to the emitter end of the phototransistor side, and the collector end of the phototransistor side is connected to the collector of transistor Q2 through resistor R1. The positive terminal of the diode on the diode side of the optocoupler PC817 is connected to the ground terminal of the voltage regulator U1. The negative terminal of the diode on the diode side splits into two branches. One branch is connected to the first terminal of capacitor C4 through resistor R2. The second terminal of capacitor C4 is connected to the ground terminal of the voltage regulator U1, and the first terminal of capacitor C4 is also connected to resistor R1. The other branch is connected to the output terminal V of the voltage regulator U1 through a resistor. out The optocoupler PC817 is used to isolate non-intrinsically safe and intrinsically safe cells.
5. An explosion-proof elevator light curtain according to claim 4, characterized in that: The output terminal V of voltage regulator U1 out Four Zener diodes, D2, D3, D4, and D5, are connected in parallel with the ground terminal of the voltage regulator U1 for current limiting and voltage limiting.
6. An explosion-proof elevator light curtain according to claim 4, characterized in that: The output terminal V out A LED branch is also connected between the output terminal V of the voltage regulator U1 and the ground terminal of the voltage regulator U1, the LED branch comprising a light emitting diode and a 2K current limiting resistor connected in series with each other.
7. An explosion-proof elevator light curtain according to claim 4, characterized in that: The light curtain unit (10) includes a transistor Q7. The base of transistor Q7 is connected to the output of an infrared receiver tube. The infrared emitter and receiver tube are used to detect whether an object is blocking the light. The infrared receiver tube outputs a signal to the base of transistor Q7 after detecting that an object has passed through. The collector of transistor Q7 is connected to the control terminal of relay K2. When an object blocks the light, the output signal of the photoelectric sensor will trigger transistor Q7 to conduct, thereby energizing the coil of relay K2. The contacts or auxiliary contacts of relay K2 will act as signal output terminals (3) connected to the external elevator main control board to control the opening and closing of the elevator doors.