Anti-explosion elevator light curtain

Abstract

The invention belongs to the technical field of elevator light curtains, and particularly relates to an anti-explosion elevator light curtain. Comprising an explosion-proof box, a power conversion control panel is arranged in the explosion-proof box, and a power input end, a signal output end, a first light curtain connecting cable and a second light curtain connecting cable are arranged on a box body of the explosion-proof box; wherein the explosion-proof box is used for placing the power supply conversion control panel inside through the explosion-proof effect of the explosion-proof box, outputting an explosion-proof power supply and driving the light curtain infrared transmitting end and the light curtain infrared receiving end through the light curtain connecting cable I and the light curtain connecting cable II; when the light curtain is shielded, a shielding signal is fed back to the power conversion control panel in the explosion-proof box through the light curtain connecting cable, and a switching signal is generated and output to an external elevator main control panel through the signal output end so as to control opening and closing of an elevator door. The device can be used in inflammable, explosive and other special environments, and has safety and reliability. The anti-explosion elevator light curtain not only fills the gap of the anti-explosion elevator light curtain on the market, but also provides a brand new safety solution for flammable and explosive places.

Description

Technical Field

[0001] The invention belongs to the technical field of elevator light curtains, and in particular relates to an explosion-proof elevator light curtain. Background Art

[0002] In modern buildings and industrial facilities, elevators are important vertical transportation tools with a wide range of applications. In particular, the safe operation of elevators is crucial in flammable and explosive places such as petrochemicals, coal mining, and pharmaceuticals. In these special environments, any potential fire source may lead to catastrophic consequences, so there are very high standards for the explosion-proof performance of elevator equipment.

[0003] Photoelectric equipment plays a key role in elevator operation. As a safety protection device for the elevator door system, the light curtain can effectively prevent the elevator door from pinching passengers or objects during the closing process. However, the common light curtains widely used on the market are only suitable for ordinary places without flammable and explosive risks. When designing ordinary light curtains, they did not fully consider the dangerous factors such as flammable gases and dust that may be faced in special environments. The internal circuit structure, optical components and shell materials of the light curtains cannot meet the safety requirements for use in flammable and explosive places.

[0004] In flammable and explosive places, elevator light curtains must not only have accurate sensing functions, but also ensure that no dangerous factors such as electric sparks and high temperatures that may cause explosions will be generated under any circumstances. Up to now, although there is an urgent demand in the market for explosion-proof elevator light curtains that can be used in such special places, related products are still blank. This situation not only limits the safe use of elevators in special environments, but also brings potential hidden dangers to the safe production of related industries. With the continuous development of industry and the increasing attention to safe production, it is urgent to develop an explosion-proof elevator light curtain suitable for flammable and explosive places. Summary of the invention

[0005] The present invention aims at the defects of the prior art and provides an explosion-proof elevator light curtain.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an explosion-proof elevator light curtain device, comprising a flameproof box, a power conversion control board built in the flameproof box, and a power input terminal, a signal output terminal, a light curtain connection cable 1, and a light curtain connection cable 2 are provided on the flameproof box body; wherein the flameproof box is used to place the power conversion control board inside through its flameproof function, output explosion-proof power and drive the light curtain infrared transmitting terminal and the light curtain infrared receiving terminal through the light curtain connection cable 1 and the light curtain connection cable 2; when the light curtain is blocked, the blocking signal is fed back to the power conversion control board in the flameproof box through the light curtain connection cable, a switch signal is generated and output to the external elevator main control board through the signal output terminal to control the opening and closing of the elevator door.

[0007] Furthermore, the circuit of the power conversion control board includes a non-intrinsically safe unit, an intrinsically safe unit, and a jointly driven light curtain unit; wherein the non-intrinsically safe unit is connected to the intrinsically safe unit, and the intrinsically safe unit is connected to the jointly driven light curtain unit.

[0008] The non-intrinsically safe unit is used to convert the 220V voltage into 12V to supply the intrinsically safe unit.

[0009] The intrinsically safe unit is used to provide an initial conduction voltage to the optocoupler PC817 through the sampling resistor R2, so that the PC817 is turned on and drives the 8050 transistor, and then drives the BU406 high-power transistor, so that the circuit is turned on and power is supplied to the linked drive light curtain unit.

[0010] Furthermore, the non-intrinsically safe unit includes an AC220V power input, which is introduced to the input end of the transformer through a fuse Fuse1. The transformer is used to convert AC220V into 12V AC power, and the output end of the transformer is connected to a rectifier bridge D1, and rectified into DC power through the rectifier bridge D1; the DC output end of the rectifier bridge D1 is smoothed by a filter capacitor C3 and 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] An input terminal VIN of the voltage regulator U1 is connected to an output V+ of the non-intrinsically safe unit through a power transistor Q1, and a ground terminal GND of the voltage regulator U1 is connected to an 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 end of the phototransistor side, and the collector end 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, and the negative terminal of the diode on the diode side is divided into two branches, one of which is connected to the first end of the capacitor C4 through the resistor R2, and the second end of the capacitor C4 is connected to the ground terminal of the voltage regulator U1, and the first end 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 the resistor; the optocoupler PC817 is used to isolate the non-intrinsically safe unit and the intrinsically safe unit.

[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 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. The LED branch includes a light emitting diode and a 2K current limiting resistor connected in series.

[0018] Furthermore, the co-driven light curtain unit includes a transistor Q7, the base of which is connected to the output of an infrared receiving tube, and an infrared transmitting tube and an infrared receiving tube for detecting whether an object blocks the light. The infrared receiving tube is used to output a signal to the base of the transistor Q7 (2N3904) after detecting that an object has passed through, i.e., the base of 2N3904, and the collector of the transistor Q7 is connected to the control end of the relay K2. When an object blocks the light, the output signal of the photoelectric sensor triggers the transistor Q7 to turn on, thereby energizing the coil of the relay K2, and the contacts or auxiliary contacts of the relay K2 are actuated, and are connected to the external elevator main control board as a signal output end to control the opening and closing of the elevator door.

[0019] Compared with the prior art, the present invention has beneficial effects.

[0020] The explosion-proof elevator light curtain of the present invention can be used in special environments such as flammable and explosive environments, and it has safety and reliability. It not only fills the gap of explosion-proof elevator light curtains in the market, but also provides a new safety solution for flammable and explosive places. By placing the power conversion control board in the flameproof box, it effectively avoids any possible sparks or arcs from threatening the surrounding environment. It not only ensures the safety of the equipment, but also provides protection for personnel and facilities working in dangerous environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. The protection scope of the present invention is not limited to the following description.

[0022] Figure 1 It is a schematic diagram of the overall structure of the explosion-proof elevator light curtain device.

[0023] Figure 2This is the circuit diagram of the power conversion control board.

[0024] Figure 3 yes Figure 2 A partial enlargement of Figure 1 .

[0025] Figure 4 yes Figure 2 A partial enlargement of Figure 2 .

[0026] Figure 5 yes Figure 2 A partial enlargement of Figure 3 . DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and beneficial effects of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0028] like Figure 1-5 As shown, a specific embodiment: an explosion-proof elevator light curtain device includes a flameproof box 1, the flameproof box 1 has a built-in power conversion control board, and the flameproof box 1 is provided with a power input terminal 2, a signal output terminal 3, a light curtain connecting cable 1 4, and a light curtain connecting cable 2 5; wherein, the flameproof box 1 is used to place the power conversion control board inside through its flameproof function, output explosion-proof power and drive the light curtain infrared transmitting terminal 6 and the light curtain infrared receiving terminal 7 through the light curtain connecting cable 1 4 and the light curtain connecting cable 2 5; the light curtain connecting cable 1 4 is connected to the light curtain infrared transmitting terminal 6, and the light curtain connecting cable 2 5 is connected to the light curtain infrared receiving terminal 7.

[0029] When the light curtain is blocked, the blocking signal is fed back to the power conversion control board in 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 opening and closing of the elevator door.

[0030] Preferably, the circuit of the power conversion control board includes a non-intrinsically safe unit 8, an intrinsically safe unit 9, and a jointly driven light curtain unit 10; 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 jointly driven light curtain unit 10; the non-intrinsically safe unit 8 is used to convert 220 volts into 12 volts to supply the intrinsically safe unit 9; the intrinsically safe unit 9 is used to provide an initial conduction voltage to the optocoupler PC817 through the sampling resistor R2, so that PC817 is turned on and drives the 8050 transistor, and then drives the BU406 high-power transistor, so that the circuit is turned on and power is supplied to the jointly driven light curtain unit 10.

[0031] Preferably, the non-intrinsically safe unit 8 includes an AC220V power input, which is introduced into the input end of the transformer through a fuse Fuse1. The transformer is used to convert AC220V into 12V AC power, and the output end of the transformer is connected to a rectifier bridge D1, and rectified into DC power by the rectifier bridge D1; the DC output end of the rectifier bridge D1 is smoothed by a filter capacitor C3 and 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), which is used to provide 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 through the 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 non-intrinsically safe unit 8 (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 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 end of the diode on the diode side of optocoupler PC817 is connected to the ground end of voltage regulator U1, and the negative end of the diode on the diode side is divided into two branches, one of which is connected to the first end of capacitor C4 through resistor R2, and the second end of capacitor C4 is connected to the ground end of voltage regulator U1, and the first end of capacitor C4 is also connected to resistor R1; the other branch is connected to the output end Vout of voltage regulator U1 through a resistor; optocoupler PC817 is used to isolate the non-intrinsically safe unit from 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 and voltage limiting. That is, the intrinsically safe circuit 9 stabilizes the circuit output voltage through the four Zener diodes D2, D3, D4, and D5 to achieve the intrinsically safe function of limiting current and voltage.

[0034] Preferably, an LED branch is further connected between the output terminal Vout of the voltage regulator U1 and the ground terminal of the voltage regulator U1 , and the LED branch includes a light emitting diode and a 2K current limiting resistor connected in series.

[0035] Preferably, the co-driven light curtain unit 10 includes an infrared transmitting tube and an infrared receiving tube for detecting whether an object blocks the light. The infrared receiving tube is used to output 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 end of relay K2. When an object blocks the light, the output signal of the photoelectric sensor will trigger transistor Q7 to turn on, thereby energizing the coil of relay K2, and the contacts or auxiliary contacts of relay K2 will be actuated, and connected to the external elevator main control board as the signal output terminal 3 to control the opening and closing of the elevator door.

[0036] The working principle is as follows: the transmitting part of the light curtain is composed of multiple infrared transmitting tubes connected in series. The receiving part is also composed of multiple infrared receiving tubes connected in series. When there is no obstruction between the transmitting and receiving tubes, the infrared receiving tube is turned on and the relay is closed. When there is an obstruction between the transmitting and receiving tubes, the infrared receiving tube cannot receive the light signal and is disconnected, and the relay is opened accordingly. In this way, the relay opens and closes back and forth with the obstruction to control the opening and closing of the door.

[0037] The working principle of the circuit of the power conversion control board is as follows: it is composed of a non-intrinsically safe unit 8, an intrinsically safe unit 9, and a co-driving light curtain unit 10. The non-intrinsically safe unit 8 converts the 220 volt voltage into 12 volts and supplies it to the intrinsically safe unit (9). The intrinsically safe unit provides an initial conduction voltage to the optocoupler PC817 through the resistor R2, so that PC817 is turned on to drive the 8050 transistor and then drives the BU406 high-power transistor to turn on the circuit to supply power to the co-driving light curtain unit 10. When the load part at the rear end of the circuit BU406 is overloaded or short-circuited, the voltage at the rear end of R2 will be immediately lowered to make PC817 lose the conduction voltage and cut off, so that the 8050 transistor is cut off, and the circuit stops supplying power to the rear end, thereby achieving the purpose of limiting current overload. The circuit stabilizes the circuit through four 13-volt Zener diodes D2, D3, D4, and D5, thereby achieving the intrinsic safety effect of limiting current and voltage.

[0038] When an obstacle blocks the transmitting and receiving parts of the infrared light curtain, the infrared light curtain will generate a blocking signal, which is transmitted to the power conversion control board in the explosion-proof box 1 through the light curtain connection cable to generate a switch signal. The signal is output to the elevator main control board through the signal output terminal 3 to control the elevator door opening and closing, so as to achieve the functions of both explosion-proof and elevator light curtain. This makes up for the current situation where there are only ordinary elevator light curtains but no explosion-proof elevator light curtains.

[0039] Specifically, the present invention achieves the purpose of explosion-proof by installing an intrinsically safe power supply board in the flameproof box 1, and uses the output explosion-proof intrinsically safe power supply to drive the infrared elevator light curtain to achieve the function of the light curtain. The light curtain strips of the infrared transmitting and receiving parts of the explosion-proof elevator light curtain of the present invention can be ordinary elevator light curtain strips or intrinsically safe elevator light curtain strips. The intrinsically safe unit is controlled by the optical coupler PC817 plus the sampling resistor R2 to control the current overload.

[0040] The explosion-proof elevator light curtain device of the present invention effectively avoids any possible sparks or arcs from threatening the surrounding environment by placing the power conversion control board in the explosion-proof box. This ensures the safety of the equipment and provides protection for personnel and facilities working in dangerous environments. In addition, the explosion-proof box is provided with a power input terminal, a signal output terminal, and a cable interface for connecting the light curtain, which is convenient and stable, making installation and maintenance easier.

[0041] The present invention adopts the division and isolation measures between non-intrinsically safe units, intrinsically safe units and the associated driving light curtain units. In particular, the optical coupler PC817 is used to achieve electrical isolation between non-intrinsically safe units and intrinsically safe units, thereby enhancing the overall safety performance of the system. At the same time, the non-intrinsically safe unit can convert the common 220 volt AC voltage into 12 volt DC voltage and supply it to the intrinsically safe unit to ensure the stable operation of the entire system. The application of the voltage regulator LM7812 further ensures the stability and reliability of the power supply, and can maintain a good working condition even in the case of large voltage fluctuations.

[0042] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "preferred embodiments", "specific implementation", or "preferred implementation" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0043] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, it should be understood by those skilled in the art that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features therein may be replaced by equivalents. Therefore, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope defined by the claims of the present invention.

Claims

1. An explosion-proof elevator light curtain device, comprising a flameproof box (1), characterized in that: The flameproof box (1) has a built-in power conversion control board, and the flameproof box (1) is provided with a power input terminal (2), a signal output terminal (3), a light curtain connection cable 1 (4), and a light curtain connection cable 2 (5); wherein, The flameproof box (1) is used to place a power conversion control board inside by virtue of its flameproof function, output explosion-proof power and drive a light curtain infrared transmitting end (6) and a light curtain infrared receiving end (7) through a light curtain connecting cable 1 (4) and a light curtain connecting cable 2 (5); when the light curtain is blocked, a blocking signal is fed back to the power conversion control board in the flameproof box (1) through the light curtain connecting cable, generating a switch signal and outputting it to an external elevator main control board through a signal output end (3) to control the opening and closing of the elevator door.

2. The explosion-proof elevator light curtain device according to claim 1, characterized in that: The circuit of the power conversion control board comprises a non-intrinsically safe unit (8), an intrinsically safe unit (9), and a jointly driven light curtain unit (10); 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 jointly driven light curtain unit (10); The non-intrinsically safe unit (8) is used to convert the 220 volt voltage into 12 volts to supply the intrinsically safe unit (9); The intrinsically safe unit (9) is used to provide an initial conduction voltage to the optical coupler PC817 through the sampling resistor R2, so that the PC817 is turned on and drives the 8050 transistor, and then drives the BU406 high-power transistor, so that the circuit is turned on and power is supplied to the jointly driven light curtain unit (10).

3. The explosion-proof elevator light curtain device according to claim 2, characterized in that: The non-intrinsically safe unit (8) comprises an AC220V power input, which is introduced into the input end of the transformer via a fuse Fuse1. The transformer is used to convert the AC220V into 12V alternating current, and the output end of the transformer is connected to a rectifier bridge D1, which is rectified into direct current through the rectifier bridge D1. The direct current output end of the rectifier bridge D1 is smoothed by a filter capacitor C3 and connected to the intrinsically safe unit (9) as the output of the non-intrinsically safe unit (8).

4. The explosion-proof elevator light curtain device according to claim 3, characterized in that: The intrinsically safe unit (9) comprises a voltage stabilizer U1, which is used to provide a stable 12V voltage output; The input terminal V of the voltage regulator U1 IN The output V+ of the non-intrinsically safe unit (8) is connected via the 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 V of the voltage regulator U1 IN The power transistor Q1 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 non-intrinsically safe unit (8), the base of transistor Q2 is connected to the phototransistor side of optical coupler 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, and the negative terminal of the diode on the diode side is divided into two branches, one of which is connected to the first terminal of the capacitor C4 through the resistor R2, and 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 V of the voltage regulator U1 through the resistor out ; Optocoupler PC817 is used to isolate non-intrinsically safe units from intrinsically safe units.

5. The explosion-proof elevator light curtain device according to claim 4, characterized in that: The output terminal V of the 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 and voltage limiting.

6. The explosion-proof elevator light curtain device according to claim 4, characterized in that: The output terminal V of the voltage regulator U1 out An LED branch is also connected to the ground terminal of the voltage regulator U1, and the LED branch includes a light emitting diode and a 2K current limiting resistor connected in series.

7. The explosion-proof elevator light curtain device according to claim 4, characterized in that: The co-driving light curtain unit (10) includes a transistor Q7, the base of which is connected to the output of an infrared receiving tube, an infrared transmitting tube and an infrared receiving tube for detecting whether an object blocks light, the infrared receiving tube is used to output a signal to the base of the transistor Q7 after detecting that an object has passed through, and the collector of the transistor Q7 is connected to the control end of the relay K2. When an object blocks light, the output signal of the photoelectric sensor triggers the transistor Q7 to turn on, thereby energizing the coil of the relay K2, causing the contact or auxiliary contact of the relay K2 to operate, and being connected to an external elevator main control board as a signal output end (3) to control the opening and closing of the elevator door.

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