Aviation ignition nozzle and maintenance method

Abstract

The present application belongs to the field of aviation and aerospace engine ignition, and particularly relates to an aviation ignition nozzle and a maintenance method. The present application belongs to the field of aviation and aerospace engine ignition, and particularly relates to an aviation ignition nozzle and a maintenance method, comprising: a bushing, a center electrode, an insulator, a shell and a gasket; the shell comprises an open end and a closed end, and the closed end has an ignition hole on the end surface; one end of the insulator has a cylindrical slot, and the bottom of the cylindrical slot has a central through hole penetrating the insulator; one end of the center electrode has an ignition cap formed by enlarging the diameter, and the other end passes through the central through hole and is placed in the cylindrical slot, the ignition cap is stuck on the end face of the insulator, and has a gap placed in the ignition hole; the gasket is welded to the center electrode by metallization brazing and is tightly attached to the bottom of the cylindrical slot, and the gasket and the ignition cap limit the axial displacement of the center electrode; the insulator is welded to the inner wall of the shell by metallization brazing. The structure is easy to disassemble and repair at a preset temperature.

Description

Technical Field

[0001] The present application belongs to the field of aviation and aerospace engine ignition, and in particular relates to an aviation ignition nozzle and a maintenance method. Background Art

[0002] The aircraft engine ignition nozzle is installed in the engine combustion chamber. The working environment temperature is high and the operating conditions are harsh. The discharge end of the ignition nozzle is in the high temperature flame burning environment of the engine for a long time, which will cause the electrode material and semiconductor glaze layer to wear out naturally. The maximum operating temperature of the engine ignition nozzle of a certain drone reaches 1000℃, and the spark energy requirement is not less than 1.5J. This high temperature, high energy and small volume requirement leads to a significant acceleration of the wear rate of the electrode material and semiconductor glaze layer at the discharge end of the ignition nozzle. The improvement of electrode materials and semiconductor materials alone cannot meet the total life requirements of the engine.

[0003] Under this premise, a method of condition-based maintenance of the ignition nozzle is proposed. After the engine has gone through a repair period, the ignition nozzle is inspected and evaluated, and repaired according to the condition to ensure that the ignition nozzle meets the use of the engine in the next overhaul period. Through condition-based maintenance, it is possible to repair as much as possible without excessive maintenance, which generally extends the total life of the ignition nozzle. Therefore, it is necessary to design an ignition nozzle structure and maintenance method that conforms to the principle of condition-based maintenance. Summary of the invention

[0004] In order to solve the above problems, the present application provides an aviation ignition nozzle, comprising:

[0005] Bushing, center electrode, insulator, shell and gasket;

[0006] The shell comprises an open end and a closed end, and an ignition hole is provided on an end surface of the closed end;

[0007] One end of the insulator has a cylindrical slot, the bottom of the cylindrical slot has a central through hole that penetrates the insulator, one end of the center electrode has an ignition cap formed by an enlarged diameter, and the other end passes through the central through hole and is placed in the cylindrical slot. The ignition cap is stuck on the end face of the insulator and has a gap in the ignition hole; the washer is welded to the center electrode by metallized brazing and is tightly attached to the bottom of the cylindrical slot, and the washer and the ignition cap limit the axial displacement of the center electrode; the insulator is welded to the inner wall of the shell by metallized brazing.

[0008] Preferably, the shell includes a large inner diameter section and a small inner diameter section, the inner diameter of the large inner diameter section is larger than the inner diameter of the small inner diameter section, the end face of the large inner diameter section is the open end, and the end face of the small inner diameter section is the closed end, the insulator includes a large outer diameter section and a small outer diameter section, the large outer diameter section is sleeved in the large inner diameter section, the small outer diameter section is sleeved in the small inner diameter section, and the large outer diameter section has the cylindrical groove at the position.

[0009] Preferably, an annular gap is formed between the ignition cap and the ignition hole by the diameter difference, and the annular gap has a preset width; the bottom of the annular gap is the end face of the insulator, and a plurality of concentric rings of the same width and staggered colors are drawn on the end face of the insulator, and the width of all concentric rings is equal to or less than the preset width, and when the ignition cap and the ignition hole are electrically corroded, the degree of electrical corrosion between the ignition cap and the ignition hole can be judged by the number of concentric rings observed in the annular gap.

[0010] Preferably, the insulator has a mounting surface at a closed end of the housing with an outer diameter reduced, and the mounting surface is used for mounting the bushing.

[0011] Preferably, the ignition hole comprises a tapered hole located on the outside and a cylindrical hole located on the inside, and the ignition cap is located in the cylindrical hole.

[0012] A maintenance method for an aviation ignition nozzle, for repairing the aviation ignition nozzle, observing the number of the concentric rings through the annular gap, and determining the ignition nozzle whose number of observed concentric rings exceeds a set threshold and the ignition nozzle whose performance exceeds the standard in the performance inspection as the ignition nozzle to be repaired;

[0013] Heat the ignition nozzle to be repaired in a high temperature box at 850℃ for at least 5 minutes to melt the metallized brazing;

[0014] Remove the insulator and center electrode from the housing, remove the center electrode from the insulator, and then remove all parts from the high temperature box;

[0015] After the parts have cooled, replace the damaged and failed parts, polish the metallized brazing parts, and reassemble;

[0016] Carry out acceptance test on the repaired ignition nozzle to ensure that the product meets the requirements.

[0017] The advantages of this application include: meeting the requirement of condition-based maintenance of the ignition nozzle, regularly inspecting and repairing the ignition nozzle, and flexibly replacing the parts according to the wear and tear of the parts, ensuring that the performance of the ignition nozzle meets the requirements of the engine, and the ignition is reliable and stable. At the same time, the service life of the ignition nozzle is extended to meet the engine's requirement for the total life of the ignition nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural diagram of an ignition nozzle according to a preferred embodiment of the present application.

[0019] Figure 2 This is a diagram of the insulator structure of a preferred embodiment of the present application.

[0020] Figure 3 This is a diagram of the central electrode structure in a preferred embodiment of the present application.

[0021] Figure 4 This is a bushing structure diagram of a preferred embodiment of the present application.

[0022] Figure 5 This is a gasket structure diagram of a preferred embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be further described in detail in detail and in detail in conjunction with the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design. In the absence of conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other to obtain new embodiments.

[0024] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installed", "connected", "connected" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal connection of two components. Technical personnel in the field can understand their specific meanings in this application according to the specific circumstances.

[0025] like Figure 1-Figure 5 As shown, in order to solve the above problems, the present application provides an aviation ignition nozzle, comprising:

[0026] Bushing 1, center electrode 2, insulator 3, shell 4 and gasket 5;

[0027] The center electrode 2 and the shell 4 are connected to different electrodes respectively, and electric sparks are generated when electricity is applied, wherein the shell 4 includes an open end and a closed end, and an ignition hole is provided on the end surface of the closed end;

[0028] One end of the insulator 3 has a cylindrical slot, and the bottom of the cylindrical slot has a central through hole that penetrates the insulator 3. One end of the center electrode 2 has an ignition cap formed by enlarging the diameter, and the other end passes through the central through hole and is placed in the cylindrical slot. The ignition cap is stuck on the end face of the insulator 3 and is placed in the ignition hole with a gap. The washer 5 is welded to the center electrode 2 by metallization brazing and is tightly attached to the bottom of the cylindrical slot. The washer 5 and the ignition cap limit the axial displacement of the center electrode 2. The insulator 3 is welded to the inner wall of the shell 4 by metallization brazing. The shell 4 includes a large inner diameter section and a small inner diameter section. The inner diameter of the large inner diameter section is larger than the inner diameter of the small inner diameter section. The end face of the large inner diameter section is the open end, and the end face of the small inner diameter section is the closed end. The insulator 3 includes a large outer diameter section and a small outer diameter section. The large outer diameter section is sleeved in the large inner diameter section, and the small outer diameter section is sleeved in the small inner diameter section. The cylindrical slot is provided at the position of the large outer diameter section.

[0029] In some optional embodiments, the ignition cap and the ignition hole form an annular gap due to the diameter difference, and the annular gap has a preset width; the bottom of the annular gap is the end face of the insulator 3, and multiple concentric rings of the same width and staggered colors are drawn on the end face of the insulator 3, and the width of all concentric rings is equal to or less than the preset width. When the ignition cap and the ignition hole are electrically corroded, the number of concentric rings observed in the annular gap is used to judge the degree of electrical corrosion between the ignition cap and the ignition hole. The insulator itself is white, and high-temperature resistant black paint is brushed on the insulator at intervals to facilitate observation of the size of the annular gap.

[0030] In some optional embodiments, the insulator 3 has a mounting surface at the closed end of the shell 4 with a reduced outer diameter, and the mounting surface is used to mount the bushing 1 .

[0031] In some optional embodiments, the ignition hole includes a tapered hole located on the outside and a cylindrical hole located on the inside, and the ignition cap is located in the cylindrical hole.

[0032] A maintenance method for an aviation ignition nozzle, for repairing the aviation ignition nozzle, observing the number of the concentric rings through the annular gap, and determining the ignition nozzle whose number of observed concentric rings exceeds a set threshold and the ignition nozzle whose performance exceeds the standard in the performance inspection as the ignition nozzle to be repaired;

[0033] Heat the ignition nozzle to be repaired in a high temperature box at 850°C for at least 5 minutes to melt the metallized brazing; specifically, set the temperature of the high temperature box at 850°C, and after the temperature stabilizes, install the repaired ignition nozzle with the threaded end facing downwards, place it in the high temperature box, and leave it for 5 minutes;

[0034] Take out the insulator 3 and the center electrode 2 from the housing 4, then take out the center electrode 2 from the insulator 3, and then take out all the parts from the high temperature box;

[0035] After the parts have cooled, the damaged and failed parts are replaced, the metallized brazing parts are polished, and the parts are reassembled. The assembly process is as follows: first, the bushing is put on the insulator, and then they are installed into the shell together, pressed and centered, and then the center electrode is inserted into the inner hole of the insulator, solder is placed at the brazing position, and then the gasket is put on the center electrode, and finally the whole is put into a high-temperature furnace for brazing and sealing.

[0036] Carry out acceptance test on the repaired ignition nozzle to ensure that the product meets the requirements.

[0037] The advantages of this application include: meeting the requirement of condition-based maintenance of the ignition nozzle, regularly inspecting and repairing the ignition nozzle, and flexibly replacing the parts according to the wear and tear of the parts, ensuring that the performance of the ignition nozzle meets the requirements of the engine, and the ignition is reliable and stable. At the same time, the service life of the ignition nozzle is extended to meet the engine's requirement for the total life of the ignition nozzle.

[0038] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An aviation ignition nozzle, characterized in that: include: Bushing (1), center electrode (2), insulator (3), shell (4) and gasket (5); The shell (4) comprises an open end and a closed end, and an ignition hole is provided on the end surface of the closed end; One end of the insulator (3) has a cylindrical slot, the bottom of the cylindrical slot has a central through hole that penetrates the insulator (3), one end of the center electrode (2) has an ignition cap formed by enlarging the diameter, and the other end passes through the central through hole and is placed in the cylindrical slot, the ignition cap is clamped on the end face of the insulator (3) and has a gap placed in the ignition hole; the washer (5) is welded to the center electrode (2) by metallization brazing and is tightly attached to the bottom of the cylindrical slot, the washer (5) and the ignition cap limit the axial displacement of the center electrode (2); the insulator (3) is welded to the inner wall surface of the shell (4) by metallization brazing.

2. The aviation ignition nozzle according to claim 1, characterized in that: The shell (4) comprises a large inner diameter section and a small inner diameter section, the inner diameter of the large inner diameter section is larger than the inner diameter of the small inner diameter section, the end face of the large inner diameter section is the open end, and the end face of the small inner diameter section is the closed end, the insulator (3) comprises a large outer diameter section and a small outer diameter section, the large outer diameter section is sleeved in the large inner diameter section, the small outer diameter section is sleeved in the small inner diameter section, and the large outer diameter section has the cylindrical slot at its position.

3. The aviation ignition nozzle according to claim 1, characterized in that: An annular gap is formed between the ignition cap and the ignition hole due to the diameter difference, and the annular gap has a preset width; the bottom of the annular gap is the end face of the insulator (3), and a plurality of concentric rings of the same width and staggered colors are drawn on the end face of the insulator (3), and the width of all the concentric rings is equal to or less than the preset width. When the ignition cap and the ignition hole are electrically corroded, the degree of electrical corrosion between the ignition cap and the ignition hole is judged by the number of concentric rings observed in the annular gap.

4. The aviation ignition nozzle according to claim 1, characterized in that: The insulator (3) has a mounting surface formed by reducing the outer diameter at the closed end of the housing (4), and the mounting surface is used for mounting the bushing (1).

5. The aviation ignition nozzle according to claim 2, characterized in that: The ignition hole comprises a conical hole located at the outside and a cylindrical hole located at the inside, and the ignition cap is located in the cylindrical hole.

6. A method for repairing an aviation ignition nozzle, used for repairing an aviation ignition nozzle as claimed in any one of claims 3 to 5, characterized in that: Observe the number of the concentric rings through the annular gap, and determine the ignition nozzles whose number of concentric rings observed exceeds a set threshold and the ignition nozzles whose performance exceeds the standard in the performance inspection as ignition nozzles to be repaired; Heat the ignition nozzle to be repaired in a high temperature box at 850℃ for at least 5 minutes to melt the metallized brazing; Remove the insulator (3) and the center electrode (2) from the housing (4), remove the center electrode (2) from the insulator (3), and then remove all parts from the high temperature box; After the parts have cooled, replace the damaged and failed parts, polish the metallized brazing parts, and reassemble; Carry out acceptance test on the repaired ignition nozzle to ensure that the product meets the requirements.

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