High-reliability head ignition small igniter

Abstract

The invention discloses a high-reliability head ignition small igniter, and belongs to the technical field of initiating explosive devices, the high-reliability head ignition small igniter comprises a tube shell, a welding assembly and an electric connector, the welding assembly comprises a shell, glass is sintered in the shell, a contact pin is packaged in the glass, one end of the contact pin is further provided with a ceramic chip, and the ceramic chip is connected with the electric connector. One end of the tube shell is inserted into the shell of the welding assembly and connected with the ceramic chip, a charging ring is arranged at the joint, and the electric connector penetrates through the other end of the shell of the welding assembly and then is connected with the other end of the contact pin of the welding assembly; the igniter is small in size, the maximum outer diameter of a tube shell of the igniter is only 10.5 mm, the overall length of the igniter is smaller than 36.3 mm, a glass sealing structure is adopted, the igniter has better pressure bearing performance and sealing performance, the requirement that leakage does not occur within 5 min under the pressure of 20 MPa can be met, the double-bridge-circuit design is adopted, when one loop breaks down, the other loop can still work normally, excitation powder is ignited, and the ignition efficiency is improved. Follow-up ignition is ensured, and the reliability is high.

Description

Technical Field

[0001] This invention relates to the field of pyrotechnics technology, and in particular to a small igniter with high reliability head ignition. Background Technology

[0002] Currently, small attitude control engines are being developed, primarily used for attitude adjustment in aircraft or large engines. These small engines typically measure Φ12cm × 25cm and mainly consist of a casing, engine nacelle, nozzle, tail fin, propellant grains, and igniter. Their internal pressure resistance is generally no less than 6MPa, and the internal temperature after startup typically reaches around 1300℃. Given this high-temperature and high-pressure internal environment, the igniter must be small in size while also possessing high pressure resistance, sealing performance, and reliability. Summary of the Invention

[0003] The purpose of this invention is to provide a small igniter with high reliability head ignition to solve the above-mentioned problems.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a small igniter with high reliability head ignition, comprising a shell, a welding assembly, and an electrical connector, wherein, The welding assembly includes a housing containing sintered glass. The pin is encapsulated within the glass, and one end of the pin is further provided with a ceramic plate. The ceramic plate has high pressure resistance and good heat dissipation. One end of the tube shell is connected to the welding assembly, and a charging ring is provided at the joint.

[0005] The electrical connector passes through the baffle and insulating sheet to connect to the pins of the welding assembly.

[0006] As a preferred technical solution, the tube shell is threadedly connected to the welding assembly.

[0007] As a preferred technical solution, a cover and a baffle A are provided on the inner side of the end of the tube shell furthest from the welding assembly. The cover is adjacent to the chemical agent, and epoxy resin (such as DG-3S) is applied at the junction of the cover and the tube shell to achieve a sealing effect. The baffle A is located at the step of the tube shell and is used for closing the tube shell.

[0008] As a preferred technical solution, an insulating sheet A is also provided. The insulating sheet A passes through the pin and is installed inside the housing of the welding assembly near the glass, forming an electrostatic channel. Epoxy resin (such as DG-4) is filled on the other side of the insulating sheet A. The insulating sheet A prevents the epoxy resin from flowing into the electrostatic channel.

[0009] As a preferred technical solution, a baffle B and an insulating sheet B are provided where the electrical connector passes through the housing. The insulating sheet B is installed at the step of the housing adjacent to epoxy resin (such as DG-4) to constrain the wires of the electrical connector. The baffle B is adjacent to the insulating sheet B, and the shield wire of the electrical connector is soldered to the baffle B. After the housing is closed with the baffle B, the shield wire of the electrical connector is connected to the housing, which can meet the requirements of electromagnetic compatibility.

[0010] As a preferred technical solution, the pins are four in number, and the four pins form two sets of circuits, with each set of circuits connected to an electrical connector.

[0011] As a preferred technical solution, the maximum outer diameter of the tube shell is Φ10.5mm, the tube shell material is 05Cr17Ni4Cu7Nb, and the material is subjected to solution treatment followed by aging at 480℃, achieving a tensile strength of σ. b >1310MPa.

[0012] As a preferred technical solution, the external thread of the housing of the welding assembly is M20×1.5-6g, the housing material is 12Cr18Ni9, and the material is solution treated to achieve a tensile strength of σ. b >520MPa.

[0013] This invention employs a glass-sealed structure, which has higher pressure resistance and better sealing performance; it also adopts a dual-circuit redundant structure design, which has higher reliability.

[0014] Compared with the prior art, the advantages of the present invention are as follows: (1) The igniter of the present invention is small in size, with a maximum outer diameter of only 10.5 mm and an overall length of less than 36.3 mm.

[0015] (2) The igniter of the present invention adopts a glass-sealed structure, in which glass is sintered inside the shell and the pin is encapsulated in the glass. Compared with the sealing structure of electrode plug plus copper ring, the glass-sealed structure has better pressure resistance and sealing performance, and can meet the requirement of no leakage for 5 minutes under a pressure of 20MPa.

[0016] (3) Under the small size design requirements, the igniter of the present invention adopts a dual-circuit redundant structure design through internal structure design to ensure higher reliability. The dual-bridge circuit design divides the four pins into two groups of circuits, each group of circuits is equipped with an electrical connector, and the entire product is powered by two electrical connectors separately. If one group of circuits fails, the other group of circuits can still function normally to ignite the ignition charge and ensure subsequent ignition.

[0017] (4) The igniter in this invention adopts a split structure. When the ratio of the depth of the welding hole to the diameter of the welding hole is greater than 2:1, the welding difficulty will increase significantly and the welding quality will also decrease significantly. Therefore, the outer shell of the product is split into two parts: the welding component and the tube shell. The welding component and the tube shell are connected by threads, which reduces the welding depth and ensures that the difficulty of welding the bridge wire on the end face of the ceramic sheet is reduced. The resistance value of the bridge wire after welding meets the requirements and the welding is firm, effectively solving the problem of "deep hole welding" in the glass sealing structure. Attached Figure Description

[0018] Figure 1 This is an overall structural diagram of the igniter according to an embodiment of the present invention; Figure 2 A cross-sectional view of the structural diagram of the welding assembly; Figure 3 This is a side view of the welding assembly; Figure 4 Diagram of the shell structure; In the diagram, 1. Tube shell; 2. Charge ring; 3. Insulating sheet A; 4. Insulating sheet B; 5. Baffle B; 6. Shell; 7. Pin; 8. Glass; 9. Ceramic sheet; 10. Cover plate; 11. Baffle A; 12. Electrical connector A; 13. Electrical connector B; 14. Epoxy resin; 15. Bridge wire. Detailed Implementation

[0019] To explain the technical content, objectives, and effects of the present invention in detail, the following specific embodiments are provided to further illustrate the content of the present invention. However, the content of the present invention is far more than the following examples.

[0020] Example 1 A highly reliable head-ignition miniature igniter, see [link / reference]. Figure 1 , Figure 2 , Figure 3 and Figure 4 It includes a housing 1, welding components, and electrical connectors, wherein, The welding assembly includes a housing 6, within which glass 8 is sintered. The pin 7 is encapsulated within the glass 8, and a ceramic sheet 9 is provided at one end of the pin 7. One end of the tube shell 1 is provided with a thread, and the threaded end is screwed into the shell 6 of the welding assembly through a threaded connection; One end of the tube shell 1 is inserted into the shell 6 of the welding assembly and connected to the ceramic plate 9. A charge ring 2 is provided at the connection point. The electrical connector passes through the other end of the housing 6 of the welding assembly and connects to the other end of the pin 7 of the welding assembly. The shell 1 is threadedly connected to the welding assembly; A cover plate 10 and a baffle A11 are provided on the inner side of the end of the tube shell 1 away from the welding assembly. The cover plate 10 is adjacent to the agent. Epoxy glue DG-3S is applied at the junction of the cover plate 10 and the tube shell 1 to achieve a sealing effect. The baffle A11 is located at the step of the tube shell and is used to close the tube shell 1. An insulating sheet A3 is also provided, which passes through the pin 7 and is installed inside the housing 6 of the welding assembly near the glass 8, forming an electrostatic channel. Epoxy resin 14 is filled on the other side of the insulating sheet A3. In this embodiment, the epoxy resin is of type DG-4. The insulating sheet A3 prevents the epoxy resin 14 from flowing into the electrostatic channel.

[0021] A baffle B5 and an insulating sheet B4 are provided where the electrical connector passes through the housing. The insulating sheet B4 is installed at the step of the housing 6 and is adjacent to the epoxy resin 14 to constrain the wires of the electrical connector. The baffle B5 is adjacent to the insulating sheet B4 and the shield wire of the electrical connector is soldered to the baffle B5. After the housing 6 is closed on the baffle B5, the shield wire of the electrical connector is connected to the housing 6, which can meet the requirements of electromagnetic compatibility. In this embodiment, there are four pins, which form two sets of circuits. Each set of circuits is connected to an electrical connector, namely electrical connector A12 and electrical connector B13. The maximum outer diameter of the tube shell is Φ10.5mm, and the tube shell material is 05Cr17Ni4Cu7Nb. The material is subjected to solution treatment and aging at 480℃, and the tensile strength reaches σ. b >1310MPa; The external thread of the housing of the welding assembly is M20×1.5-6g, and the housing material is 12Cr18Ni9, which has undergone solution treatment and has a tensile strength of σ. b >520MPa.

[0022] The welding assembly and the shell 1 are connected by threads, which reduces the welding depth and ensures that the difficulty of welding the bridge wire 15 on the end face of the ceramic sheet 9 is reduced. The resistance value of the bridge wire after welding meets the requirements and the welding is firm, effectively solving the problem of "deep hole welding" in the glass sealing structure.

[0023] The igniter of this embodiment underwent relevant performance tests: The test method for "insulation resistance" is as follows: at room temperature, apply (500±50)V to the product foot-to-shell. DC voltage, duration 2 minutes, product insulation resistance greater than 20MΩ; The test method for "safe current" is as follows: At room temperature, apply a DC current of 1A to the product pin-to-pin for 5 minutes. The product should not ignite. The test method for "electrostatic discharge" is as follows: under room temperature conditions, discharge once to the product's foot-shell. The discharge conditions are: voltage 25000V±500V, resistance 5000Ω±250Ω, and capacitance 500pF±25pF. The product should not ignite. The test method for "stray current" is as follows: At room temperature, apply 2000 pulses with an amplitude of 100mA±5mA and a duration of 300ms±5ms to the product pin-to-pin. The product should not ignite. The vibration test method is as follows: fix the product on the vibration test bench and conduct a vibration test on the product. The test frequency is 5Hz to 500Hz, the amplitude is 10mm, and the direction is three directions: X, Y, and Z. The time for each direction is 2h. After the vibration test, the product should not be damaged and should be able to work reliably. The impact test method is as follows: the product is fixed on an impact test bench and subjected to an impact test with peak accelerations of 65g and durations of 9ms, and 200g and 1.5ms. The impact directions are X, Y, and Z, with one impact in each direction. The product should not be damaged after the impact test and should be able to work reliably. The test method for "temperature shock" is as follows: store the product at 65℃±2℃ for 4 hours, then transfer the product to -45℃±2℃ within 5 minutes and keep it at that temperature for 4 hours. After repeating this cycle 3 times, the product can work reliably. The test method for "high temperature operation" is as follows: store the product at 65℃±2℃ for 4 hours, and conduct an ignition output test on the product within 5 minutes. The product can work reliably. The test method for "low temperature operation" is as follows: store the product at -45℃±2℃ for 4 hours, and conduct an ignition output test on the product within 5 minutes. The product can work reliably. The test method for "high current surge" is as follows: install the product in a volume of 45 cm. After securely connecting the product to the Y11X-0804ZJ10-2 (Factory 855) socket on the pressure testing bullet, connect it to the data acquisition and testing system. Perform an ignition test on a single circuit of the product using 22.0A±0.5A DC current. The ignition delay time must be ≤15ms; after ignition, the product must meet the output pressure test requirements and sealing requirements. The test method for "ignition output" is as follows: Install the product on a pressure test ball with a volume of 45 cm³, securely connect the product to the Y11X-0804ZJ10-2 socket, and connect it to the data acquisition and testing system. Apply a 5A~8A DC current with a 200ms pulse to each circuit of the product for the ignition test. The ignition output time must not exceed 15ms, the peak pressure within 100ms after pressure build-up must be 2MPa~4MPa, and the pressure must not be less than 1.5MPa within 50ms after pressure build-up. The test method for “sealing and strength” is as follows: after the product is ignited, it is installed on a high-pressure airtightness test bench, a gas pressure of 20MPa is continuously applied, and the product is placed in water for 5 minutes.

[0024] The test results are shown in Table 1 below.

[0025] Table 1. Igniter performance test results of Example 1 Serial Number Test Project Number of tests (tests) Test results 1 Insulation resistance 96 1500 MΩ~46000 MΩ 2 Safe current 96 None of the products will ignite. 3 electrostatic discharge 96 None of the products will ignite. 4 stray current 96 None of the products will ignite. 5 vibration 36 The product structure is undamaged and it functions normally. 6 Impact 36 The product structure is undamaged and it functions normally. 7 Temperature shock 36 It can work normally 8 High-temperature work 21 It can work normally 9 Low temperature operation 21 It can work normally 10 High current surge 3 The product reliably ignites and meets the output pressure test requirements and sealing requirements after ignition. 11 ignition output 52 The product reliably ignites and meets the output pressure test requirements after ignition. 12 Sealing and strength 36 The product did not leak when subjected to a continuous 20MPa gas pressure for 5 minutes. The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A small igniter with high reliability head ignition, characterized in that, Includes the casing, welding components, and electrical connectors, among which, The welding assembly includes a housing containing sintered glass, with the pin encapsulated within the glass. One end of the pin is further provided with a ceramic plate. One end of the tube shell is inserted into the housing of the welding assembly and connected to the ceramic plate. A charge ring is provided at the connection point. The electrical connector passes through the other end of the housing of the welding assembly and connects to the other end of the pins of the welding assembly.

2. The miniature igniter with high reliability head ignition according to claim 1, characterized in that, The tube shell is threadedly connected to the welding assembly.

3. The miniature igniter with high reliability head ignition according to claim 1, characterized in that, A cover and baffle A are provided on the inner side of the end of the tube shell away from the welding assembly.

4. The miniature igniter with high reliability head ignition according to claim 1, characterized in that, An insulating sheet A is also provided, which passes through the pin and is installed inside the housing of the welding assembly near the glass to form an electrostatic channel.

5. The miniature igniter with high reliability head ignition according to claim 1, characterized in that, A baffle B and an insulating sheet B are provided where the electrical connector passes through the housing.

6. The miniature igniter with high reliability head ignition according to claim 1, characterized in that, The pins consist of four pins, which form two sets of circuits. Each set of circuits is connected to an electrical connector.

7. The miniature igniter with high reliability head ignition according to claim 1, characterized in that, The maximum outer diameter of the tube shell is Φ10.5mm, and the tube shell material is 05Cr17Ni4Cu7Nb, which is subjected to solution treatment and aging at 480℃.

8. The miniature igniter with high reliability head ignition according to claim 1, characterized in that, The external thread of the housing of the welding assembly is M20×1.5-6g, and the housing material is 12Cr18Ni9, which has undergone solution treatment.

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