Ignition end structure of semiconductor electrode and method for manufacturing the same

Abstract

The application discloses a firing end structure of a semiconductor electrode and a preparation method thereof. The firing end structure comprises a shell (3), a semiconductor block (1) and a second porcelain tube (6) are sequentially arranged in the shell (3) along an axial direction from a firing end to a tail end; a connecting cavity (8) is arranged on a butt joint surface of the semiconductor block (1) and the second porcelain tube (6); a first porcelain tube (4) is arranged in the connecting cavity (8) and used for connecting the semiconductor block (1) and the second porcelain tube (6); the first porcelain tube (4) is penetrated by a center electrode (2); a head end of the center electrode (2) is flush with the firing end of the shell (3) after penetrating the semiconductor block (1); and a tail end of the center electrode (2) is connected with a guide rod (7). The application solves the technical problems of the prior art, such as difficulty in processing an insulating porcelain tube, easy electrode disengagement and insufficient creepage distance when the insulating porcelain tube is sleeved.

Description

Technical Field

[0001] This invention belongs to the field of engine electric ignition technology, specifically relating to the ignition end structure and preparation method of a semiconductor electric nozzle. Background Technology

[0002] The ignition nozzle is an important component of the aircraft engine ignition system. Its function is to generate an electric spark by breaking down the spark gap with a high-voltage pulse generated by the ignition device, so as to ignite the combustible gas mixture in the engine combustion chamber.

[0003] An ignition nozzle typically includes components such as a side electrode, a center electrode, a housing, and a semiconductor block. The center electrode is mainly used to transmit high-voltage pulses to the ignition end of the ignition nozzle. Together with the side electrode, it forms a potential difference on the surface of the semiconductor block, breaking down the semiconductor block to generate an electric spark.

[0004] To meet the internal insulation requirements of ignition nozzles, alumina ceramics with high flexural strength and high operating temperature are typically used as the insulating medium. Existing ignition nozzles all employ insulating ceramic tubes with extremely high aspect ratios to isolate the central electrode component from the housing, and have elongated holes machined inside. Due to the poor toughness of alumina ceramics, existing technologies significantly increase the manufacturing difficulty of the insulating ceramic tubes, resulting in poor manufacturability of the ignition nozzles. Summary of the Invention

[0005] The purpose of this invention is to provide a ignition end structure and manufacturing method for a semiconductor electric nozzle. This invention solves the technical problems of existing technologies, such as the difficulty in processing insulating ceramic tubes, the ease with which electrodes can detach, and insufficient creepage distance when insulating ceramic tubes are fitted together.

[0006] The technical solution of the present invention is: an ignition end structure of an ignition nozzle, comprising a housing, wherein a semiconductor block and a second ceramic tube are sequentially arranged along the axial direction from the ignition end to the tail end inside the housing; a connecting cavity is provided on the mating surface of the semiconductor block and the second ceramic tube, and a first ceramic tube is provided in the connecting cavity for connecting the semiconductor block and the second ceramic tube, wherein a central electrode passes through the first ceramic tube, and the head end of the central electrode protrudes from the semiconductor block and is flush with the ignition end of the housing; the tail end of the central electrode is connected to a guide rod.

[0007] In the aforementioned ignition nozzle ignition end structure, the semiconductor block end and the housing ignition end are fitted together by an anti-detachment bevel.

[0008] In the aforementioned ignition nozzle ignition end structure, the connecting cavity is also filled with sealant.

[0009] In the aforementioned ignition nozzle ignition end structure, the tail end of the central electrode extends out of the first ceramic tube and is provided with a boss.

[0010] In the aforementioned ignition nozzle's firing end structure, the central electrode and the guide rod are mortise and tenon jointed and welded together as a whole.

[0011] In the aforementioned ignition nozzle's ignition end structure, the central electrode and guide rod are welded using argon arc welding, laser welding, or furnace brazing.

[0012] In the aforementioned ignition tip structure, cooling holes are distributed circumferentially on the ignition tip end face of the housing, and an air inlet is provided on the side wall of the housing; a ventilation channel is formed between the semiconductor block, the second ceramic tube, and the inner wall of the housing; the cooling holes are connected to the air inlet via the ventilation channel.

[0013] The aforementioned method for preparing the ignition end structure of the ignition nozzle is as follows: the central electrode and the guide rod are welded together to form a central circuit, one end of the guide rod is inserted into the second ceramic tube, and then sealant is filled into the gap between the second ceramic tube, the central electrode and the guide rod. One end of the central electrode is inserted into the first ceramic tube and the semiconductor block in sequence, the semiconductor block is pressed along the axial direction, and then the whole assembly is placed in the housing for curing.

[0014] The advantages of this invention are:

[0015] 1. The technical solution of the present invention provides an ignition end structure and preparation method for an ignition nozzle, which splits the high aspect ratio insulating ceramic tube into several assembled insulating ceramic tubes, reducing the processing difficulty and manufacturing cost of the insulating ceramic tube and improving the manufacturability of the product.

[0016] 2. The electrode boss structure design can effectively prevent the electrode from falling into the engine after welding failure, thus improving the safety of the ignition nozzle.

[0017] 3. By using insulating ceramic tubes and filling with sealant, the creepage distance is doubled, which can effectively prevent flashover and breakdown inside the ignition nozzle and improve the reliability of the product. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the ignition end structure of the electric nozzle of the present invention;

[0019] The components are: 1. Semiconductor block, 2. Center electrode, 3. Housing, 4. First ceramic tube, 5. Sealant, 6. Second ceramic tube, and 7. Guide rod.

[0020] Figure 2 This is a schematic diagram illustrating the main features of the ignition nozzle of the present invention;

[0021] The components include: 8 connecting cavity, 9 anti-detachment slope, 10 boss, 11 cooling hole, 12 air inlet and 13 ventilation channel. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0023] Example 1. An ignition tip structure of an ignition nozzle, configured as follows: Figure 1 and 2 As shown, the device includes a housing 3. Inside the housing 3, a semiconductor block 1 and a second ceramic tube 6 are arranged sequentially along the axial direction from the ignition end to the tail end. A connecting cavity 8 is provided on the mating surface of the semiconductor block 1 and the second ceramic tube 6. A first ceramic tube 4 is provided in the connecting cavity 8 for connecting the semiconductor block 1 and the second ceramic tube 6. The first ceramic tube 4 is passed through by a central electrode 2. The head end of the central electrode 2 passes through the semiconductor block 1 and is flush with the ignition end of the housing 3. The tail end of the central electrode 2 is connected to a guide rod 7.

[0024] The original high aspect ratio insulating ceramic tube of the ignition nozzle was decomposed into semiconductor block 1, first ceramic tube 4 and second ceramic tube 6, which solved the problem of poor manufacturability of insulating ceramic tubes of similar ignition nozzles.

[0025] The aforementioned semiconductor block 1 head end and the firing end of the housing 3 are engaged by the anti-detachment inclined surface 9.

[0026] The aforementioned connecting cavity 8 is also filled with sealant 5.

[0027] Semiconductor block 1 and second ceramic tube 6 are connected through first ceramic tube 4. At the same time, the cavity is filled with sealant 5, which increases the creepage distance between the central line formed by the central electrode 2 and the housing 3.

[0028] The aforementioned center electrode 2 has a protrusion 10 after it extends out of the first ceramic tube 4.

[0029] If the welding of the center electrode 2 and the guide rod 7 fails, the protrusion 10 can prevent the center electrode 2 from detaching from the firing end structure and falling into the engine, thus affecting flight safety.

[0030] The aforementioned center electrode 2 and guide rod 7 are mortise and tenon jointed and welded together as a whole.

[0031] The aforementioned center electrode 2 and guide rod 7 are welded using argon arc welding, laser welding, or furnace brazing.

[0032] The aforementioned housing 3 has cooling holes 11 distributed around the firing end face, and air inlets 12 are provided on the side wall of the housing 3; a ventilation channel 13 is formed between the semiconductor block 1, the second ceramic tube 6 and the inner wall of the housing 3; the cooling holes 11 are connected to the air inlets 12 via the ventilation channel 13.

[0033] The aforementioned method for preparing the ignition end structure of the ignition nozzle is as follows: the central electrode 2 and the guide rod 7 are welded together to form a central circuit. One end of the guide rod 7 is inserted into the second ceramic tube 6. Then, sealant 5 is filled into the gap between the second ceramic tube 6, the central electrode 2, and the guide rod 7. One end of the central electrode 2 is sequentially inserted into the first ceramic tube 4 and the semiconductor block 1. The semiconductor block 1 is pressed along the axial direction. Then, the whole assembly is placed in the housing 3 and cured for 24 hours to complete the preparation of the ignition end structure.

Claims

1. An ignition end structure for an ignition nozzle, characterized in that: The device includes a housing. Inside the housing, a semiconductor block and a second ceramic tube are arranged sequentially along the axial direction from the ignition end to the tail end. A connecting cavity is provided on the mating surface of the semiconductor block and the second ceramic tube. The connecting cavity structure is as follows: a cavity A formed by the concave end face of the tail end of the semiconductor block and a cavity B formed by the concave end face of the head end of the second ceramic tube are mated on the mating surface to form a closed connecting cavity. A first ceramic tube is provided inside the connecting cavity. One end of the first ceramic tube extends into cavity A, and the other end extends into cavity B, which is used to connect the semiconductor block and the second ceramic tube axially. A central electrode passes through the first ceramic tube. The head end of the central electrode passes through the semiconductor block and is flush with the ignition end of the housing. The tail end of the central electrode is connected to a guide rod. A boss is provided on the tail end of the central electrode after it passes through the first ceramic tube.

2. The ignition end structure of the ignition nozzle according to claim 1, characterized in that: The semiconductor block head end and the housing firing end are fitted together by an anti-detachment bevel.

3. The ignition end structure of the ignition nozzle according to claim 1, characterized in that: The connecting cavity is also filled with sealant.

4. The ignition end structure of the ignition nozzle according to claim 1, characterized in that: The center electrode and the guide rod are fitted with mortise and tenon joints and welded together as a whole.

5. The ignition end structure of the ignition nozzle according to claim 1, characterized in that: The center electrode and the guide rod are welded using argon arc welding, laser welding, or furnace brazing.

6. The ignition end structure of the ignition nozzle according to claim 1, characterized in that: The shell's firing end face is also provided with cooling holes in the circumferential direction, and the shell's side wall is provided with air inlet holes; a ventilation channel is formed between the semiconductor block, the second ceramic tube, and the inner wall of the shell; the cooling holes are connected to the air inlet holes through the ventilation channel.

7. A method for preparing the ignition end structure of an ignition nozzle as described in any one of claims 1-6, characterized in that: The central electrode and the guide rod are welded together to form the central circuit. One end of the guide rod is inserted into the second ceramic tube. Then, sealant is filled into the gap between the second ceramic tube, the central electrode, and the guide rod. One end of the central electrode is inserted into the first ceramic tube and the semiconductor block in sequence. The semiconductor block is pressed along the axial direction and then the whole thing is placed in the shell for curing.

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