Integrated insulated and sealed engine semiconductor sparking plug structure

Abstract

The invention discloses an integrated insulated and sealed engine semiconductor sparking plug structure, and particularly relates to the field of aviation and airspace engine ignition devices. Comprising a shell in which an insulator is sleeved; a first groove body, a second groove body, a third groove body and a fourth groove body which are communicated with one another are sequentially formed along the axial direction of the insulator; the sealing positioning piece comprises a baffle and a positioning rod which are vertically connected, the baffle is perpendicular to the insulator and located in the first groove body, and the outer diameter of the baffle is larger than the outer diameter of the positioning rod and smaller than the inner diameter of the first groove body; the positioning rod is located in the second groove body, and the outer diameter of the positioning rod is equal to the inner diameter of the second groove body; a positioning groove is inwards formed in the free end of the positioning rod; the central electrode is located in the insulator, one end of the central electrode extends into the positioning groove and is in threaded connection, and the other end of the central electrode is sleeved with a semiconductor block which is located in the fourth groove body. Based on the conductor sparking plug structure, the insulating strength can be improved, and the working performance of the semiconductor sparking plug in the whole life cycle is stable and reliable.

Description

Technical Field

[0001] This application relates to the field of ignition devices for aviation and aerospace engines, and in particular to an integrated, insulated, and sealed semiconductor nozzle structure for engines. Background Technology

[0002] Semiconductor nozzles for aero-engines are mounted on the combustion chamber casing and must withstand mechanical shocks such as vibration, impact, and acceleration transmitted by the engine. The discharge end of the semiconductor nozzle extends deep into the combustion chamber, exposed to high-temperature exhaust gases. The harsh operating conditions place the nozzle in different temperature and pressure fields at its front and rear ends, and the nozzle itself experiences significant temperature and pressure differences. Therefore, semiconductor nozzles should possess the following properties: good insulation, high discharge efficiency, and stable electrical performance after long-term use; good high-temperature and thermal shock resistance, maintaining a certain mechanical strength at high temperatures; chemical stability, adapting to the combustion chamber atmosphere and resisting corrosion; and good sealing to prevent high-temperature gases from leaking out of the combustion chamber.

[0003] Semiconductor nozzles typically employ a ceramic-sleeved sealing structure. The central electrode is sealed to the insulator in the first stage, and the insulator assembly is sealed to the housing in the second stage. The melting temperature of the second sealant must be lower than that of the first sealant, and a semiconductor glaze is sintered onto the insulator end face as the discharge functional material. This sealing structure requires a sleeved insulator and is suitable for large-volume nozzles with a length of at least 90mm and a diameter of at least 16.5mm. Applying this sealing method to small-sized semiconductor nozzles would reduce insulation strength. Furthermore, existing semiconductor nozzles using semiconductor glaze as the discharge functional material operate at spark energies greater than 0.3J, leading to potential semiconductor glaze depletion and failure within their lifespan. Summary of the Invention

[0004] The main objective of this application is to provide an integrated, insulated, and sealed engine semiconductor nozzle structure, which aims to solve the problems of low insulation strength and short lifespan of existing semiconductor nozzles.

[0005] To achieve the above objectives, this application provides an integrated insulating and sealed engine semiconductor nozzle structure, comprising: a housing, with an insulator sleeved inside the housing; a first groove, a second groove, a third groove, and a fourth groove sequentially formed along the axial direction of the insulator, the inner diameters of the first groove, the second groove, and the third groove decreasing sequentially, and the inner diameter of the fourth groove being larger than that of the third groove; a sealing positioning element, including a vertically connected baffle and a positioning rod, the baffle being perpendicular to the insulator and located within the first groove, the outer diameter of the baffle being larger than the outer diameter of the positioning rod and smaller than the inner diameter of the first groove; the positioning rod being located within the second groove, the outer diameter of the positioning rod being equal to the inner diameter of the second groove; a positioning groove formed inward at the free end of the positioning rod; and a central electrode located within the insulator, one end extending into the positioning groove and connected by a thread, the other end being sleeved with a semiconductor block located within the fourth groove.

[0006] Optionally, the sealing positioning element is plated with a nickel layer and brazed to seal it to the insulator.

[0007] Optionally, the outer edge of the baffle forms a gap with the inner wall of the first groove, and solder is placed in the gap to braze and seal the end face of the baffle with the insulator; an annular groove is formed on the outer wall of the other end of the positioning rod, and solder is placed in the annular groove to braze and seal the positioning rod with the insulator.

[0008] Optionally, the surface of the central electrode is plated with a silver layer.

[0009] Optionally, the length of the center electrode is 44.2-44.8 mm, and the surface of the ignition end of the center electrode is formed with a step with a maximum diameter of 5.8 mm; the inner diameter of the semiconductor block is 3.5 mm, the outer diameter is 9.4 mm, and the length is 10.8-11.2 mm; the diameter of the baffle is 9.5 mm, the thickness is 1.5 mm, the length of the positioning rod is 10 mm, and the depth of the positioning groove is 6 mm.

[0010] Optionally, a fifth groove is also provided in the insulator. The fifth groove is located between the third groove and the fourth groove, and its inner diameter is located between the two. A fastening sleeve is provided in the fifth groove. The fastening sleeve is sleeved on the central electrode, and one end is fixed to the semiconductor block by glass glue.

[0011] Optionally, a bushing is provided between the housing and the insulator at the connection between the upper and lower housings, and the insulator and the bushing are brazed to seal the connection.

[0012] Optionally, the bushing material is 4J34 seal alloy.

[0013] Compared with the prior art, the beneficial effects of this application are as follows: The integrated insulating and sealed engine semiconductor nozzle structure of this invention features a sealing and positioning component. A baffle seals the second groove, thereby sealing the central electrode. Simultaneously, a positioning rod positions and seals the central electrode, further improving sealing performance. Combined with an integrated insulator, this enhances insulation strength. The ignition end of the central electrode is fitted with a semiconductor block, which can be a SiC semiconductor block. Using this as a discharge material, the spark energy can be increased to 0.3J, ensuring stable and reliable performance throughout the entire lifespan of the semiconductor nozzle. The central electrode surface is plated with a silver layer and has threads. These threads serve several purposes: firstly, the threaded connection allows for adjustment of the axial length by controlling the number of rotations; secondly, the threaded connection with the sealing and positioning component increases the contact area, reducing the central circuit resistance and improving voltage transmission, thus reducing energy loss; and thirdly, it allows for tension adjustment, ensuring a tight fit between the central electrode and the semiconductor block, and between the semiconductor block and the insulator, eliminating assembly gaps, thereby reducing discharge voltage and insulation resistance. This also enhances the overall internal strength of the semiconductor nozzle, reducing the risk of the central electrode breaking off and falling into the engine. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of an integrated insulating and sealed engine semiconductor nozzle structure according to this application; Figure 2 This is a schematic diagram of the insulator structure in an integrated insulating and sealed engine semiconductor nozzle structure according to this application; Figure 3 This is a schematic diagram of the sealing positioning element in an integrated insulating and sealed engine semiconductor nozzle structure according to this application; Figure 4 This is a schematic diagram of the sealing structure in an integrated insulating and sealed engine semiconductor nozzle structure according to this application; Figure 5 This is a schematic diagram of the semiconductor block in an integrated insulating and sealed engine semiconductor nozzle structure according to this application; Figure 6 This is a schematic diagram of the central electrode in an integrated insulating and sealed engine semiconductor nozzle structure according to this application.

[0015] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0017] This invention provides an integrated, insulated, and sealed engine semiconductor nozzle structure, such as... Figure 1-6 As shown, it includes: a housing 1, with an insulator 2 sleeved inside the housing 1; a first groove 3, a second groove 4, a third groove 5, and a fourth groove 6 that are interconnected and sequentially formed along the axial direction of the insulator 2, the inner diameters of the first groove 3, the second groove 4, and the third groove 5 decreasing sequentially, and the inner diameter of the fourth groove 6 being larger than the inner diameter of the third groove 5; a sealing and positioning element 7, including a baffle 71 and a positioning rod 72 connected vertically, the baffle 71 being perpendicular to the insulator 2 and located inside the first groove 3, the outer diameter of the baffle 71 being larger than the outer diameter of the positioning rod 72; the positioning rod 72 being located inside the second groove 4, the outer diameter of the positioning rod 72 being equal to the inner diameter of the second groove 4; a positioning groove 73 being formed inwardly at the free end of the positioning rod 72; and a center electrode 8, the surface of which is plated with a silver layer, located inside the insulator 2, one end extending into the positioning groove 73 and connected by a thread, the other end being sleeved with a semiconductor block 9, the semiconductor block 9 being located in the fourth groove 6.

[0018] In this embodiment, a sealing positioning component 7 is provided, which seals the second groove 4 through the baffle 71, thereby sealing the center electrode 8. At the same time, the positioning rod 72 positions and seals the center electrode 8, further improving the sealing performance. Combined with the integrated insulator 2, it can improve the insulation strength. The ignition end of the center electrode 8 is sleeved with a semiconductor block 9, which can be a SiC semiconductor block 9. Using it as a discharge functional material, the spark energy can be increased to 0.3J, and the working performance of the semiconductor nozzle can be stable and reliable throughout its entire life cycle. The surface of the center electrode 8 is plated with a silver layer and has threads. The functions of the threads are as follows: First, the threads serve as a connection method, and the axial length can be adjusted by controlling the number of rotations. The threaded connection with the sealing positioning component 7 increases the contact area, which can reduce the central circuit resistance, improve the voltage transmission effect, and thus reduce energy loss. Second, it can adjust the tension to ensure a tight fit between the center electrode 8 and the semiconductor block 9, and between the semiconductor block 9 and the insulator 2, eliminating assembly gaps, thereby reducing the discharge voltage and insulation resistance, while improving the overall internal strength of the semiconductor nozzle and reducing the risk of the center electrode breaking and falling into the engine. In addition, the insulator 2 is integrally molded and runs through the inside of the semiconductor nozzle, meeting the mechanical strength and rigidity requirements of the structural components for assembly and use; the material of the insulator 2 is A-95 alumina ceramic, which is hot-pressed and then sintered at high temperature to ensure that the ceramic parts meet the thermal-mechanical environment of the engine without failure when the nozzle is working.

[0019] Furthermore, the sealing positioning element 7 is plated with a nickel layer and brazed to seal it with the insulator 2. Specifically, a gap is formed between the inner wall of the first groove 3 and the outer edge of the baffle 71, and solder is placed in the gap. Brazing is performed between the end face of the baffle 71 and the insulator 2. An annular groove 74 is formed on the outer wall of the other end of the positioning rod 72. The end face of the baffle 71 that contacts the inner wall of the insulator 2 is plated with a nickel layer, and solder is placed in the annular groove 74. Brazing is performed between the positioning rod 72 and the insulator 2. Through the above two positions, a double brazing seal is achieved between the sealing positioning element 7 and the ceramic insulator 2, further improving the sealing performance and ensuring the insulation strength.

[0020] For example, the center electrode 8 has a length of 44.2-44.8 mm, and the surface of the ignition end is stepped (the semiconductor block 9 is fitted onto the step), with a maximum diameter of 5.8 mm; the semiconductor block 9 has an inner diameter of 3.5 mm, an outer diameter of 9.4 mm, and a length of 10.8-11.2 mm; the baffle 71 has a diameter of 9.5 mm and a thickness of 1.5 mm; the positioning rod 72 has a length of 10 mm; and the positioning groove 73 has a depth of 6 mm. The discharge end of the center electrode 8 is set to a large diameter of 5.8 mm, while the remaining positions are M3, adopting a flush discharge structure, which improves the electrode's resistance to electrical corrosion and can meet the life requirement of 2500 cycles for the semiconductor nozzle.

[0021] The positioning groove 73 has a depth of 6mm to ensure a reliable threaded connection with the center electrode 8 and to reserve sufficient adjustment margin for the center circuit size. The maximum diameter of the discharge end of the center electrode 8 is 5.8mm, which is more than 93% larger than that of a 3mm diameter electrode, greatly improving the electrode volume and resistance to electrical corrosion. The inner and outer diameters and length of the semiconductor block 9 first ensure its own strength and match the assembly dimensions between the center electrode 8 and the insulator 2.

[0022] Furthermore, a fifth groove 10 is formed within the insulator 2, located between the third groove 5 and the fourth groove 6, with its inner diameter falling between the two. A fastening sleeve 11 is installed within the fifth groove 10, fitting onto the central electrode 8 via a threaded connection. One end of the fastening sleeve is fixed to the semiconductor block 9 with silicone sealant. This serves to secure the semiconductor block 9 and the central electrode 8. The fastening sleeve 11 can be a nut, providing a tightening function.

[0023] A bushing 12 is provided between the housing 1 and the insulator 2, located at the connection between the upper and lower housings 1. The surface of the insulator 2 that contacts the bushing 12 is plated with a nickel layer and is brazed to seal with the bushing 12. The bushing 12 is made of 4J34 sealing alloy. The bushing 12 is assembled inside the interface between the upper and lower housings 1 and welded into one piece, ensuring that the exposed metal part of the housing 1 is made of more corrosion-resistant GH3044 high-temperature alloy material. The bushing 12, made of 4J34 sealing alloy, is brazed to the insulator 2, improving the tri-proof performance of the semiconductor nozzle and meeting the requirements for use in marine environments.

[0024] The assembly method of the semiconductor electric nozzle in this embodiment is as follows: the semiconductor block 9 and the center electrode 8 are fixed by the fastening sleeve 11, inserted into the insulator 2 from one end, and connected into a whole by the sealing positioning member 7 at the other end; the bushing is welded into the housing 1, the insulator 2 is inserted into the housing 1 as a whole and brazed to seal, and finally the anti-wave ring 13 is installed at the end of the housing 1 to close the opening.

[0025] The semiconductor electric nozzle of this embodiment was tested for structural strength and sealing performance, and the test results are as follows.

[0026] 1. Insulator 2 Performance Verification Ceramic parts undergo dielectric strength testing, flexural strength testing, thermal shock resistance testing, and water absorption testing.

[0027] a) Dielectric strength test Technical requirement: The ceramic body shall not break down under AC 10kV for 30 seconds.

[0028] Test results: Meets requirements, no parts were damaged.

[0029] b) Flexural strength Technical requirements: Not less than 1.5kN.

[0030] Test results: Meets the requirements; see Table 1 for specific data.

[0031] Table 1 Flexural Strength Test Data

[0032] c) Thermal shock resistance test Technical requirements: Select 3 pieces, heat at 800℃ for 15 minutes, repeat three times, and the surface of the porcelain should be free of cracks.

[0033] Test result: Meets requirements.

[0034] d) Water absorption rate Technical requirement: ≤0.1%.

[0035] Test results: Meets the requirements; see Table 2 for specific data.

[0036] Table 2 Water Absorption Rate Test Data

[0037] Test results for ceramic parts: Meets requirements.

[0038] 2. Performance verification of semiconductor electric nozzle products Two test pieces were fabricated using an integrated insulating and sealing structure. After assembly, performance tests were conducted, including minimum ignition voltage, airtightness, insulation resistance, and spark energy. Test results: Meets requirements; specific data are shown in Table 3.

[0039] Table 3 Performance Test Data

[0040] 2. Environmental testing and verification of semiconductor electric nozzles The semiconductor nozzle, using an integrated insulating and sealed structure, underwent initial pre-flight environmental testing. The tests included low-temperature testing, low-pressure (altitude) testing, high-temperature testing, temperature shock testing, rain testing, acceleration testing, impact testing (functionality), impact testing (crash safety), vibration testing, temperature-humidity-altitude testing, fouling testing, ignition system simulation operation baseline testing, and electromagnetic compatibility testing. The semiconductor nozzle was switched on more than 2,500 times in total. After the tests, the functional performance of the semiconductor nozzle was tested and found to be qualified.

[0041] 3. Semiconductor-based fuel injector engine test and verification The semiconductor electric nozzle, which uses an integrated insulating and sealed structure, passed the test run of a certain type of engine. Upon return to the factory for inspection, the structure was found to be intact and its performance qualified.

[0042] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. An integrated, insulated, and sealed engine semiconductor nozzle structure, characterized in that, include: The housing contains an insulator fitted inside it. A first groove, a second groove, a third groove, and a fourth groove are sequentially formed along the axial direction of the insulator. The inner diameters of the first groove, the second groove, and the third groove decrease sequentially, and the inner diameter of the fourth groove is larger than that of the third groove. A sealing positioning element includes a vertically connected baffle and a positioning rod. The baffle is perpendicular to the insulator and located in a first groove. The outer diameter of the baffle is larger than the outer diameter of the positioning rod and smaller than the inner diameter of the first groove. The positioning rod is located in the second groove, and the outer diameter of the positioning rod is equal to the inner diameter of the second groove; the free end of the positioning rod has a positioning groove opening inward; The center electrode is located inside the insulator. One end extends into the positioning groove and is connected by a thread, while the other end is fitted with a semiconductor block located in the fourth groove.

2. The integrated insulating and sealed engine semiconductor nozzle structure according to claim 1, characterized in that, The sealing positioning element is plated with a nickel layer and is brazed to seal it to the insulator.

3. The integrated insulating and sealed engine semiconductor nozzle structure according to claim 2, characterized in that, The outer edge of the baffle forms a gap with the inner wall of the first groove, and solder is placed in the gap. The end face of the baffle is brazed and sealed with the insulator. The other end of the positioning rod has an annular groove on its outer wall, and solder is placed in the annular groove. The positioning rod is brazed and sealed with the insulator.

4. The integrated insulating and sealed engine semiconductor nozzle structure according to claim 1, characterized in that, The surface of the central electrode is plated with a silver layer.

5. The integrated insulating and sealed engine semiconductor nozzle structure according to claim 1, characterized in that, The length of the central electrode is 44.2-44.8 mm, and the surface of the ignition end of the central electrode forms a step with a maximum diameter of 5.8 mm; The semiconductor block has an inner diameter of 3.5 mm, an outer diameter of 9.4 mm, and a length of 10.8-11.2 mm. The baffle has a diameter of 9.5 mm, a thickness of 1.5 mm, a positioning rod length of 10 mm, and a positioning groove depth of 6 mm.

6. The integrated insulating and sealed engine semiconductor nozzle structure according to claim 1, characterized in that, The insulator is further provided with a fifth groove, which is located between the third groove and the fourth groove, and its inner diameter is located between the two. The fifth tank is equipped with a fastening sleeve, which is fitted onto the central electrode, and one end is fixed to the semiconductor block with glass glue.

7. The integrated insulating and sealed engine semiconductor nozzle structure according to claim 1, characterized in that, A bushing is provided between the housing and the insulator, located at the connection between the upper and lower housings, and the insulator and the bushing are brazed to seal the connection.

8. The integrated insulating and sealed engine semiconductor nozzle structure according to claim 1, characterized in that, The bushing is made of 4J34 bonded alloy.

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