A reliable monitoring device for the ground connection of a pyrotechnic charge

Abstract

The utility model relates to a kind of pyrotechnics grounding reliability monitoring equipment, belong to grounding monitoring technical field;Including grounding resistance test suite and explosion-proof suite;Wherein, grounding resistance test suite includes first circuit and matched first cable;Explosion-proof suite includes the explosion-proof steel pipe for the first cable is worn into it, and the explosion-proof box into which first circuit is placed;Including small-current constant current source in the first circuit;First cable is 4 core cable;Wherein the first core and the third core one end is connected to the position near the connecting point of original grounding wire on the monitored object;Second core and fourth core one end are connected to the position different from the original grounding wire and grounding busbar connecting point;The other end of first core and second core is respectively connected the positive and negative pole of small-current constant current source;The other end of third core and fourth core is respectively the positive and negative output end of grounding test signal.The utility model improves grounding reliability, on-site safety and operation and maintenance efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of grounding detection technology, and in particular relates to a grounding reliability monitoring device for pyrotechnic products. Background Technology

[0002] During the production, storage, transportation, and on-site loading of pyrotechnics (such as electric detonators, detonators, and igniters), national military standards and the "Blasting Safety Regulations" mandate that all metal casings, tooling, and equipment enclosures must maintain reliable electrical grounding to prevent accidental explosions caused by static electricity buildup or stray currents. Grounding resistance is typically required to be ≤1Ω, and for some highly sensitive pyrotechnics, even ≤0.1Ω. Therefore, regularly conducting rapid and accurate reliability tests on the grounding system, or before and after critical processes, is a crucial step in ensuring the safety of pyrotechnics.

[0003] Currently, commonly used testing methods in the industry include:

[0004] Handheld digital micro-ohmmeters or clamp-on grounding resistance testers; these instruments generally have a large test current, which may generate sparks or Joule heat at the contact point, posing a risk of explosion; and they are easily affected by lead resistance and contact resistance, resulting in low measurement accuracy.

[0005] An online grounding monitoring device continuously injects milliampere-level current into the grounding busbar via a 24V intrinsically safe power supply to achieve real-time monitoring. However, this device can only monitor the overall resistance of the busbar and cannot quickly locate the failure point of a specific tool, fixture, or local grounding wire; even if the overall resistance of the busbar is qualified but a local branch wire is loose, safety hazards may still remain.

[0006] Portable megohmmeter + manual re-inspection: After insulation testing with a megohmmeter, the grounding resistance is then checked using a multimeter. This method is inefficient, produces discrete data, lacks traceability, and the megohmmeter's output voltage is as high as 250V to 1000V, posing a secondary risk to electrostatic-sensitive pyrotechnics.

[0007] Therefore, there is an urgent need for a grounding reliability monitoring device for pyrotechnic products that meets explosion-proof requirements, enables online monitoring, has high measurement accuracy, and causes zero damage to the original system. Utility Model Content

[0008] Based on the above analysis, the present invention aims to provide a grounding reliability monitoring device for pyrotechnic products, so as to solve the defects of the existing grounding reliability testing methods for pyrotechnic products.

[0009] The objective of this utility model is mainly achieved through the following technical solutions:

[0010] This utility model discloses a grounding reliability monitoring device for pyrotechnic products, including a grounding resistance testing kit and an explosion-proof kit;

[0011] The grounding resistance test kit includes a first circuit and a matching first cable; the explosion-proof kit includes an explosion-proof steel pipe for threading the first cable through it, and an explosion-proof box for placing the first circuit inside it.

[0012] The first circuit includes a small constant current source for grounding resistance testing; the first cable is a 4-core cable; one end of the first and third cores of the 4-core cable is connected to a position near the connection point of the original grounding wire on the monitored object; one end of the second and fourth cores is connected to a position different from the connection point of the original grounding wire and the grounding busbar; the other ends of the first and second cores are respectively connected to the positive and negative terminals of the small constant current source; the other ends of the third and fourth cores are respectively the positive and negative output terminals of the grounding test signal.

[0013] Furthermore, it also includes in-situ detection kits;

[0014] The in-situ detection kit includes a second circuit, an explosion-proof in-situ sensor, and a matching second cable;

[0015] The second circuit is placed in an explosion-proof box. The second circuit includes a power supply for powering the explosion-proof in-situ sensor. The power supply is connected to the explosion-proof in-situ sensor through a second cable that passes through the explosion-proof steel pipe, and supplies power to the explosion-proof in-situ sensor.

[0016] The explosion-proof in-situ sensor is fixed in the effective sensing area for in-situ monitoring of the monitored object by a fixed bracket; the sensing head is facing the monitored object.

[0017] The detection signal output terminal of the explosion-proof in-situ sensor is connected to one core wire of the second cable.

[0018] Furthermore, the explosion-proof in-situ sensor is a photoelectric proximity sensor, a capacitive proximity sensor, an inductive proximity sensor, or an ultrasonic proximity sensor.

[0019] Furthermore, the explosion-proof box is also equipped with a first explosion-proof connector that connects to the first cable, and the core wire of the first cable enters the interior of the explosion-proof box through the first explosion-proof connector;

[0020] The explosion-proof box is also equipped with a second explosion-proof connector that connects to the second cable. The core wire of the second cable enters the interior of the explosion-proof box through the second explosion-proof connector.

[0021] Furthermore, a switch assembly is also provided in the explosion-proof box. The first switch and the second switch of the switch assembly are respectively connected between the positive and negative terminals of the small current constant current source and the first core and the second core of the first cable.

[0022] The third and fourth switches of the switching assembly are respectively connected between the positive and negative terminals of the power supply for the position sensor and the corresponding core wires of the second cable.

[0023] Furthermore, the low-current constant current source includes resistors R1, R2, R3, and R4, diode D1, transistor Q1, three-terminal voltage regulator U1, a first connection terminal, and a second connection terminal;

[0024] The positive terminal of the power supply is connected to the first connection terminal through resistor R1; the second connection terminal is connected to the collector of transistor Q1 through resistor R2; the emitter of transistor Q1 is connected to the negative terminal of the power supply through resistor R3; and the base of transistor Q1 is connected to pin 2 of three-terminal regulator U1.

[0025] The first pin of the three-terminal regulator U1 is connected to the emitter of transistor Q1, the second pin is connected to the positive terminal of the power supply through resistor R4, and the third pin is connected to the negative terminal of the power supply.

[0026] The first connection terminal is connected to a location near the connection point of the original grounding wire of the monitored object through the first core of the first cable; the second connection terminal is connected to the grounding busbar through the second core of the first cable at a location different from the connection point between the original grounding wire and the grounding busbar.

[0027] Diode D1 is connected between the first connection terminal and the second connection terminal. The first connection terminal is connected to the anode of diode D1, and the second connection terminal is connected to the cathode of diode D1.

[0028] Furthermore, a first controlled switch K1 is connected between the first connection terminal and R1, and a second controlled switch K2 is connected between the second connection terminal and R2.

[0029] Furthermore, it also includes a sampling resistor R5, a filter circuit, and a current sensing circuit;

[0030] The sampling resistor R5 is connected in series to the constant current source power supply circuit;

[0031] The input terminal of the filter circuit is connected to both ends of the sampling resistor R5, and the output terminal is connected to the current sensing circuit.

[0032] The filtering circuit filters the signal sampled by the sampling resistor R5 and outputs it to the current sensing circuit; the current sensing circuit senses the current signal from the signal output by the filtering circuit and outputs a voltage value corresponding to the current value flowing through the sampling resistor R5.

[0033] Furthermore, it includes 4 sets of grounding resistance test kits for grounding reliability monitoring of 4 pyrotechnic items; the first circuit of the 4 sets of grounding resistance test kits is placed in the same explosion-proof box, and 4 first explosion-proof connectors are provided on the explosion-proof box; the core wire of the first cable in each grounding resistance test kit is connected to the explosion-proof box and connected to the corresponding first circuit.

[0034] Furthermore, it also includes 4 sets of in-situ detection kits for in-situ monitoring of 4 pyrotechnic items; the second circuits of the 4 sets of in-situ monitoring kits are all placed in the explosion-proof box, and the explosion-proof box is equipped with 4 second explosion-proof connectors; the core wire of the second cable in each in-situ monitoring kit is connected to the inside of the explosion-proof box and connected to the corresponding second circuit.

[0035] The beneficial effects that this utility model can achieve are as follows:

[0036] This utility model discloses a grounding reliability monitoring device for pyrotechnics. It utilizes a simple circuit based on a small-current constant current source to accurately measure the grounding resistance of pyrotechnics under explosion-proof conditions, avoiding the risk of detonation caused by high current or high voltage. Explosion-proof steel pipes, explosion-proof boxes, and explosion-proof connectors completely isolate cables and circuits from ignition sources, ensuring intrinsic safety. The in-situ detection kit enables real-time monitoring of the in-situ status of pyrotechnics, accurately monitoring only those pyrotechnics in place, avoiding false alarms caused by mismonitoring of out-of-situ pyrotechnics. The multi-channel expansion scheme allows four pyrotechnics to share a single explosion-proof box, resulting in a compact structure, low cost, and convenient maintenance. The overall device improves grounding reliability, on-site safety, and operational efficiency, and is suitable for long-term online monitoring of pyrotechnics in flammable and explosive environments. Attached Figure Description

[0037] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0038] Figure 1 This is a schematic diagram showing the composition and connection of the pyrotechnic grounding reliability monitoring device in this embodiment of the present invention;

[0039] Figure 2 This is a circuit diagram of a small current constant current source in an embodiment of this utility model;

[0040] Figure 3 This is an external view of an explosion-proof box according to an embodiment of the present utility model.

[0041] Reference numerals: 1-Explosion-proof box, 2-First circuit, 3-Second circuit, 4-First explosion-proof connector, 5-Second explosion-proof connector, 6-Monitored object, 7-Grounding busbar, 8-Original grounding wire, 9-First cable, 10-Explosion-proof in-situ sensor, 11-Second cable, 12-Explosion-proof steel pipe. Detailed Implementation

[0042] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.

[0043] To make the technical problems solved by this utility model, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model,

[0044] All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this utility model.

[0045] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0047] A specific embodiment of this utility model discloses a grounding reliability monitoring device for pyrotechnic devices, such as... Figure 1 As shown, it includes a grounding resistance test kit and an explosion-proof kit;

[0048] The grounding resistance test kit includes a first circuit and a matching first cable; the explosion-proof kit includes an explosion-proof steel pipe for threading the first cable through it, and an explosion-proof box for placing the first circuit inside it.

[0049] The first circuit includes a small constant current source for grounding resistance testing; the first cable is a 4-core cable; one end of the first and third cores of the 4-core cable is connected to a position near the connection point of the original grounding wire on the monitored object; one end of the second and fourth cores is connected to a position different from the connection point of the original grounding wire and the grounding busbar; the other ends of the first and second cores are respectively connected to the positive and negative terminals of the small constant current source; the other ends of the third and fourth cores are respectively the positive and negative output terminals of the grounding test signal.

[0050] The location near the connection point of the original grounding wire is generally within 5cm of the original grounding wire terminal on the outer shell of the monitored object. A terminal block is set within this range, and the first and third cores of the 4-core cable are connected to this terminal block.

[0051] The purpose of connecting one end of the second and fourth cores to different locations from the connection point of the original grounding wire and the grounding busbar is to prevent false monitoring events that would occur when the original grounding wire and the second and fourth cores are disconnected from the grounding busbar, thus improving the reliability of monitoring.

[0052] Preferably, the first cable is a 4-core RVV4x0.75 flexible cable, connected to the pyrotechnic device and grounding busbar using copper connector clamps. Specifically, the first and third cores of the first cable are connected to terminals on the pyrotechnic device's outer casing using copper connector clamps, while the second and fourth cores are connected to the grounding busbar using copper connector clamps. This cold-connection method using copper connector clamps facilitates connection and disconnection and does not introduce other factors that could endanger the safety of the pyrotechnic device.

[0053] A simple circuit based on a low-current constant source and a 4-core cable is used to accurately measure the grounding resistance of pyrotechnics under explosion-proof conditions, avoiding the risk of explosion caused by high current or high voltage; explosion-proof steel pipes, explosion-proof boxes and explosion-proof connectors completely isolate the cable and circuit from the fire source, ensuring intrinsic safety.

[0054] exist Figure 1 The system also includes the in-situ detection kit in the preferred scheme;

[0055] The in-situ detection kit includes a second circuit, an explosion-proof in-situ sensor, and a matching second cable;

[0056] The second circuit is placed in an explosion-proof box. The second circuit includes a power supply for powering the explosion-proof in-situ sensor. The power supply is connected to the explosion-proof in-situ sensor through a second cable that passes through the explosion-proof steel pipe, and supplies power to the explosion-proof in-situ sensor.

[0057] The explosion-proof in-situ sensor is fixed in the effective sensing area for in-situ monitoring of the monitored object by a fixed bracket; the sensing head is facing the monitored object.

[0058] The detection signal output terminal of the explosion-proof in-situ sensor is connected to one core wire of the second cable, and the in-situ detection signal is output to the explosion-proof box.

[0059] The in-situ detection kit enables real-time monitoring of the in-situ status of pyrotechnics. When used in conjunction with the grounding resistance test kit, it can accurately perform grounding reliability tests only on pyrotechnics that are in place, avoiding false alarms caused by unreliable grounding due to incorrect testing of pyrotechnics that are not in place.

[0060] Specifically, the explosion-proof in-situ sensor is fixed in the effective sensing area for in-situ monitoring of the monitored object by a fixed bracket; the sensing head is facing the monitored object.

[0061] The effective sensing area is a range of 10mm to 400mm in front of the sensing head; when there is an object in this range, the in-situ sensor outputs an in-situ signal, otherwise it outputs an out-of-situ signal.

[0062] Preferably, the in-situ sensor is a photoelectric proximity sensor, a capacitive proximity sensor, an inductive proximity sensor, or an ultrasonic proximity sensor. The appropriate proximity sensor can be selected based on the specific equipment installation environment and monitoring requirements.

[0063] The second circuit includes a power supply circuit corresponding to the selected explosion-proof in-situ sensor, which may be a circuit given in the sensor manual or a preferred circuit in other published documents; and the second circuit may also include an RC filter circuit for filtering the in-situ signal.

[0064] For example, a dust- and gas-resistant, explosion-proof, and interference-resistant photoelectric proximity sensor (also known as a photoelectric proximity switch) can be used; the light-emitting device and the photoelectric device are mounted in the same detection head in a certain direction. When a reflective surface (the object being detected) approaches, the photoelectric device receives the reflected light and outputs a signal, thus "sensing" the approach of an object and outputting a presence signal.

[0065] Preferably, the photoelectric proximity sensor is fixedly mounted below the pyrotechnic storage rack via a mounting bracket. The mounting bracket has a notched slot. When the photoelectric proximity sensor is inserted into the slot, its detection head is positioned directly above the pyrotechnic item. Once initially installed on the pyrotechnic storage rack, the mounting bracket is not removed; the photoelectric proximity sensor is simply removed when the product is changed. Moving the pyrotechnic storage rack also requires only removing the photoelectric proximity sensor from the notched slot.

[0066] Specifically, the explosion-proof box is also equipped with a first explosion-proof connector that connects to the first cable, and the core wire of the first cable enters the interior of the explosion-proof box through the first explosion-proof connector;

[0067] The explosion-proof box is also equipped with a second explosion-proof connector that connects to the second cable. The core wire of the second cable enters the interior of the explosion-proof box through the second explosion-proof connector.

[0068] The explosion-proof box, the first explosion-proof connector, and the second explosion-proof connector all meet the IIBT4 explosion-proof requirements.

[0069] Preferably, the explosion-proof box is further provided with a switch assembly, wherein the first switch and the second switch of the switch assembly are respectively connected between the positive and negative terminals of the small current constant current source and the first core and the second core of the first cable;

[0070] The third and fourth switches of the switching assembly are respectively connected between the positive and negative terminals of the power supply for the position sensor and the corresponding core wires of the second cable.

[0071] When the first and second switches in the switching assembly are closed, the grounding reliability test of the pyrotechnic device is achieved; when the third and fourth switches are closed, the in-situ detection of the pyrotechnic device is achieved. This enables the grounding reliability test of the in-situ pyrotechnic device.

[0072] When the first, second, third, and fourth switches in the switching assembly are disconnected, the pyrotechnic grounding reliability monitoring equipment is completely disconnected from the pyrotechnic, ensuring that there are no other external connections on the pyrotechnic when grounding reliability testing is not performed, thereby avoiding any potential safety impact on the pyrotechnic from external connections.

[0073] like Figure 2 As shown in the figure, this embodiment provides a specific small current constant current source, including resistors R1, R2, R3, and R4, diode D1, transistor Q1, three-terminal regulator U1, first connection terminal, and second connection terminal;

[0074] The positive terminal of the power supply is connected to the first connection terminal through resistor R1; the second connection terminal is connected to the collector of transistor Q1 through resistor R2; the emitter of transistor Q1 is connected to the negative terminal of the power supply through resistor R3; and the base of transistor Q1 is connected to pin 2 of three-terminal regulator U1.

[0075] The first pin of the three-terminal regulator U1 is connected to the emitter of transistor Q1, the second pin is connected to the positive terminal of the power supply through resistor R4, and the third pin is connected to the negative terminal of the power supply.

[0076] The first connection terminal is connected to the location near the connection point of the original grounding wire of the monitored object through the first core of the first cable; the second connection terminal is connected to the grounding busbar through the second core of the first cable at a location different from the connection point between the original grounding wire and the grounding busbar.

[0077] Diode D1 is connected between the first connection terminal and the second connection terminal. The first connection terminal is connected to the anode of diode D1, and the second connection terminal is connected to the cathode of diode D1.

[0078] The power supply circuit for grounding reliability monitoring, constructed using a small-current constant current source in this embodiment, is as follows:

[0079] V+→R1→First connection terminal→Ground wire under test→Grounding busbar→Second connection terminal→R2→Q1→R3→V-;

[0080] By extracting the voltage values ​​at both ends of the ground wire being tested, the resistance value can be calculated using the commonly used four-wire method, and the grounding resistance value can be obtained. Based on the grounding resistance value, the grounding reliability of the ground wire being tested can be determined.

[0081] Specifically, the three-terminal regulator U1 is TL3431.

[0082] Figure 2 In this circuit, resistors R1, R2, and R3 are all current-limiting resistors, which limit the current value in the power supply circuit so that the current in the circuit meets the requirements of small current.

[0083] Preferably, the resistor R2 is a wire-wound resistor. Wire-wound resistors have open-circuit failure characteristics; when the current is too large, the alloy resistance wire of the wire-wound resistor melts and the circuit is completely broken, which can protect the system in extreme cases.

[0084] The three-terminal regulator U1 and the transistor Q1 form a constant current source, with the transistor Q1 acting as a current regulator. During the current adjustment process, the three-terminal regulator U1 adjusts the base current of the transistor Q1 according to the voltage drop across the resistor R3, maintaining a constant emitter current of the transistor Q1 and ensuring the stability of the current in the circuit.

[0085] By designing the resistance value and power supply, the current source provides a stable 0.1mA current to the test power supply circuit, thus achieving safe current control.

[0086] The junction voltage of diode D1, connected between the first and second connection terminals, is used to limit the voltage drop across the tested component connected between the first and second connection terminals. When the voltage drop across the tested component exceeds the junction voltage of diode D1, diode D1 conducts to discharge current. Through diode D1, voltage limiting is added while ensuring safe current control, thus guaranteeing that the output power remains low, thereby achieving system safety protection.

[0087] For example, the low-current constant current source provides 0.1mA for resistance monitoring, with a ground resistance detection range of 0–10Ω and a maximum resistance voltage monitoring range of 1mV. The junction voltage of diode D1 is 0.6V. This 0.6V forward voltage is used as a safety voltage for the resistor terminals for protection. When the voltage between the first and second terminals exceeds 0.6V, diode D1 conducts, and the supply current is discharged through the conducting diode D1. This prevents high current from being applied to the object under test, thus achieving system safety protection.

[0088] To ensure that power is supplied to the object under test only during testing and stopped when not testing, and to stop supplying power when the supply current exceeds the safe current, a preferred embodiment of this solution also adds a controlled switch to the power supply circuit.

[0089] like Figure 2 As shown, a first controlled switch K1 is connected between the first connection terminal and R1, and a second controlled switch K2 is connected between the second connection terminal and R2.

[0090] The first controlled switch K1 and the second controlled switch K2 provide overall control of the power supply circuit. During the test, both switches are simultaneously turned on to supply power to the object under test. After the test, both switches are simultaneously turned off to isolate the object under test from the constant current source. Furthermore, if the current exceeds the limit during the test, the system safety can be ensured by disconnecting the switches.

[0091] Preferably, the first controlled switch K1 and the second controlled switch K2 are relays.

[0092] In order to monitor the current in the power supply circuit, Figure 2 It also includes sampling resistor R5, filter circuit and current sensing circuit;

[0093] The sampling resistor R5 is connected in series to the constant current source power supply circuit;

[0094] The input terminal of the filter circuit is connected to both ends of the sampling resistor R5, and the output terminal is connected to the current sensing circuit.

[0095] The filtering circuit filters the signal sampled by the sampling resistor R5 and outputs it to the current sensing circuit; the current sensing circuit senses the current signal from the filtered sampling signal output by the filtering circuit and outputs a voltage value corresponding to the current value flowing through the sampling resistor R5.

[0096] Specifically, the sampling resistor R5 is a small-value resistor of less than 10 ohms, connected between the resistor R1 and the first controlled switch. Preferably, the sampling resistor R5 is 2Ω 0.1%.

[0097] Specifically, the filter circuit includes resistors R6, R7, R8, and capacitor C1; wherein, resistor R6 is connected in parallel with sampling resistor R5, one end of resistor R6 is connected to one end of capacitor C1 through resistor R7, and the other end of resistor R6 is connected to the other end of capacitor C1 through resistor R8.

[0098] Preferably, the current sensing amplifier U2 in the current sensing circuit is INA180A4IDBVR.

[0099] The current sensing amplifier U2 outputs the induced current value IOUT at pin 1, grounds pin 2, pins 3 and 4 are connected to the two ends of the current sampling resistor R5 through a filter network, and pin 5 is connected to the positive terminal of the power supply.

[0100] The current value in the circuit can be sensed through the sampling resistor R5, the filter circuit, and the current sensing circuit. This sensed current value can be used for safety protection during the test process. That is, when the sensed current value is higher than the set value, the circuit current can be disconnected by controlling the first controlled switch K1 and the second controlled switch K2, thereby ensuring safety.

[0101] In another specific embodiment, a grounding reliability monitoring device for pyrotechnics is also disclosed, which simultaneously monitors the grounding reliability of four pyrotechnics. The device includes four sets of grounding resistance test kits for testing the grounding reliability of the four pyrotechnics. The first circuit of the four sets of grounding resistance test kits is placed in the same explosion-proof box, and four first explosion-proof connectors are provided on the explosion-proof box. The core wire of the first cable in each grounding resistance test kit is connected to the inside of the explosion-proof box and connected to the corresponding first circuit.

[0102] Preferably, it also includes 4 sets of in-situ detection kits for in-situ monitoring of 4 pyrotechnic items; the second circuits of the 4 sets of in-situ monitoring kits are all placed in the explosion-proof box, and the explosion-proof box is provided with 4 second explosion-proof connectors; the core wire of the second cable in each in-situ monitoring kit is connected to the inside of the explosion-proof box and connected to the corresponding second circuit.

[0103] The appearance of the explosion-proof box is as follows Figure 3 As shown, eight explosion connectors are used to connect the first cables of four grounding resistance test kits to the inside of the explosion-proof box; and to connect the second cables of four in-situ detection kits to the inside of the explosion-proof box.

[0104] The device uses four pyrotechnic devices sharing one explosion-proof box, which is compact, low-cost, and easy to maintain. The overall equipment improves grounding reliability, on-site safety, and operation and maintenance efficiency, and is suitable for long-term online monitoring of pyrotechnic devices in flammable and explosive environments.

[0105] In summary, this utility model's pyrotechnic grounding reliability monitoring device uses a simple circuit based on a small-current constant current source to accurately measure the grounding resistance of pyrotechnics under explosion-proof conditions, avoiding the risk of detonation caused by large currents or high voltages. Explosion-proof steel pipes, explosion-proof boxes, and explosion-proof connectors completely isolate cables and circuits from ignition sources, ensuring intrinsic safety. The optional in-situ detection kit enables real-time monitoring of the in-situ status of pyrotechnics, accurately performing grounding reliability tests only on in-situ pyrotechnics, avoiding false alarms caused by incorrect testing of out-of-situ pyrotechnics. The multi-channel expansion scheme allows four pyrotechnics to share a single explosion-proof box, resulting in a compact structure, low cost, and convenient maintenance. The overall device improves grounding reliability, on-site safety, and operational efficiency, and is suitable for long-term online monitoring of pyrotechnics in flammable and explosive environments.

[0106] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A grounding reliability monitoring device for pyrotechnic products, characterized in that, Includes grounding resistance test kits and explosion-proof kits; The grounding resistance test kit includes a first circuit and a matching first cable; the explosion-proof kit includes an explosion-proof steel pipe for threading the first cable through it, and an explosion-proof box for placing the first circuit inside it. The first circuit includes a small constant current source for grounding resistance testing; the first cable is a 4-core cable; one end of the first and third cores of the 4-core cable is connected to a position near the connection point of the original grounding wire on the monitored object; one end of the second and fourth cores is connected to a position different from the connection point of the original grounding wire and the grounding busbar; the other ends of the first and second cores are respectively connected to the positive and negative terminals of the small constant current source; the other ends of the third and fourth cores are respectively the positive and negative output terminals of the grounding test signal.

2. The grounding reliability monitoring equipment for pyrotechnic devices according to claim 1, characterized in that, It also includes in-situ detection kits; The in-situ detection kit includes a second circuit, an explosion-proof in-situ sensor, and a matching second cable; The second circuit is placed in an explosion-proof box. The second circuit includes a power supply for powering the explosion-proof in-situ sensor. The power supply is connected to the explosion-proof in-situ sensor through a second cable that passes through the explosion-proof steel pipe, and supplies power to the explosion-proof in-situ sensor. The explosion-proof in-situ sensor is fixed in the effective sensing area for in-situ monitoring of the monitored object by a fixed bracket; the sensing head is facing the monitored object. The detection signal output terminal of the explosion-proof in-situ sensor is connected to one core wire of the second cable.

3. The grounding reliability monitoring equipment for pyrotechnic devices according to claim 2, characterized in that, The explosion-proof in-situ sensor is a photoelectric proximity sensor, a capacitive proximity sensor, an inductive proximity sensor, or an ultrasonic proximity sensor.

4. The grounding reliability monitoring equipment for pyrotechnic devices according to claim 2, characterized in that, The explosion-proof box is also equipped with a first explosion-proof connector that connects to the first cable, and the core wire of the first cable enters the interior of the explosion-proof box through the first explosion-proof connector; The explosion-proof box is also equipped with a second explosion-proof connector that connects to the second cable. The core wire of the second cable enters the interior of the explosion-proof box through the second explosion-proof connector.

5. The grounding reliability monitoring equipment for pyrotechnic devices according to claim 2, characterized in that, The explosion-proof box is also equipped with a switch assembly. The first and second switches of the switch assembly are respectively connected between the positive and negative terminals of the small current constant current source and the first and second cores of the first cable. The third and fourth switches of the switching assembly are respectively connected between the positive and negative terminals of the power supply for the position sensor and the corresponding core wires of the second cable.

6. The grounding reliability monitoring equipment for pyrotechnic devices according to claim 1, characterized in that, The low-current constant current source includes resistors R1, R2, R3, and R4, diode D1, transistor Q1, three-terminal voltage regulator U1, a first connection terminal, and a second connection terminal. The positive terminal of the power supply is connected to the first connection terminal through resistor R1; the second connection terminal is connected to the collector of transistor Q1 through resistor R2; the emitter of transistor Q1 is connected to the negative terminal of the power supply through resistor R3; and the base of transistor Q1 is connected to pin 2 of three-terminal regulator U1. The first pin of the three-terminal regulator U1 is connected to the emitter of transistor Q1, the second pin is connected to the positive terminal of the power supply through resistor R4, and the third pin is connected to the negative terminal of the power supply. The first connection terminal is connected to a location near the connection point of the original grounding wire of the monitored object through the first core of the first cable; the second connection terminal is connected to the grounding busbar through the second core of the first cable at a location different from the connection point between the original grounding wire and the grounding busbar. Diode D1 is connected between the first connection terminal and the second connection terminal. The first connection terminal is connected to the anode of diode D1, and the second connection terminal is connected to the cathode of diode D1.

7. The grounding reliability monitoring device for pyrotechnic products according to claim 6, characterized in that, A first controlled switch K1 is connected between the first connection terminal and R1, and a second controlled switch K2 is connected between the second connection terminal and R2.

8. The grounding reliability monitoring device for pyrotechnic products according to claim 6, characterized in that, It also includes sampling resistor R5, filter circuit and current sensing circuit; The sampling resistor R5 is connected in series to the constant current source power supply circuit; The input terminal of the filter circuit is connected to both ends of the sampling resistor R5, and the output terminal is connected to the current sensing circuit. The filtering circuit filters the signal sampled by the sampling resistor R5 and outputs it to the current sensing circuit. The current sensing circuit senses the current signal from the signal output by the filter circuit and outputs a voltage value corresponding to the current value flowing through the sampling resistor R5.

9. The grounding reliability monitoring equipment for pyrotechnic devices according to claim 1, characterized in that, It includes 4 sets of grounding resistance test kits, which are used to monitor the grounding reliability of 4 pyrotechnic devices. The first circuit of the 4 sets of grounding resistance test kits is placed in the same explosion-proof box, and the explosion-proof box is equipped with 4 first explosion-proof connectors. The core wire of the first cable in each grounding resistance test kit is connected to the explosion-proof box and connected to the corresponding first circuit.

10. The grounding reliability monitoring device for pyrotechnic products according to claim 9, characterized in that, It also includes 4 sets of in-situ monitoring kits for in-situ monitoring of 4 pyrotechnic items; the second circuits of the 4 sets of in-situ monitoring kits are all placed in the explosion-proof box, and the explosion-proof box is equipped with 4 second explosion-proof connectors; the core wire of the second cable in each in-situ monitoring kit is connected to the explosion-proof box and connected to the corresponding second circuit.

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