Sealing structure of aviation ignition electric nozzle

Abstract

The invention belongs to the field of aviation and airspace engine ignition, and particularly relates to an aviation ignition electric nozzle sealing structure which comprises a stamping insulator, sealant, an insulator, a lining and a shell. The insulator is sleeved with the cylindrical shell through the lining, the lining is attached to the inner wall of the shell in an extruding mode, a gap is formed between the insulator and the inner cylindrical face of the shell through the diameter difference, the inner cylindrical face of the shell is provided with internal threads at the position of the gap, and the gap is filled with sealant in a molten state. And the sealant is axially extruded through the annular stamping insulator, so that the gap is filled with the sealant. The problem that gas leakage exceeds the standard after the ignition electric nozzle is used is solved, the surface of the sealant is in a threaded shape after dissection, product reliability is improved, and good economic benefits and social benefits are achieved.

Description

Technical Field

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

[0002] The ignition nozzle is installed on the side wall of the combustion chamber of the engine or starter, with one end extending into the combustion chamber and the other end located on the outer wall of the combustion chamber, connected to the ignition cable. To prevent the high-temperature fuel mixture in the combustion chamber from leaking into the engine duct, a sealing structure must be inside the nozzle. The sealing rubber compound is prone to leaking in the sealing part of the housing in a vibration, impact, and high-temperature environment, and fuel and air leak from the leaking channel, causing the ignition nozzle to leak excessively. Summary of the invention

[0003] In order to solve the above problems, the present application provides an aviation ignition nozzle sealing structure, comprising:

[0004] Stamped insulators, sealants, insulators, bushings and housings;

[0005] The insulator is sleeved in a cylindrical shell through a bushing, and the bushing is squeezed and fitted with the inner wall of the shell. A gap is formed between the insulator and the inner cylindrical surface of the shell due to the diameter difference. At the position of the gap, the inner cylindrical surface of the shell has an internal thread. The gap is filled with molten sealant, and the sealant is axially extruded by the annular stamping insulator so that the sealant fills the gap.

[0006] Preferably, the insulator comprises a cylindrical section and a tapered section with a gradually increasing diameter at the end, the middle section of the bushing has a radially inward groove, the inner wall surface of the bushing has a tapered surface, and the tapered surface of the bushing fits with the tapered surface of the tapered section of the insulator.

[0007] Preferably, the diameter of the cylindrical section of the insulator is smaller than the inner diameter of the housing.

[0008] Preferably, when the aviation ignition nozzle sealing structure is sealed, the aviation ignition nozzle sealing structure is heated to a molten state of the sealant, and the sealant is pressurized by punching the insulator, and after the pressurization is completed, it is cooled to room temperature to complete the sealing.

[0009] Preferably, the insulator and the stamped insulator are both made of alumina ceramic materials, and the shell is made of high-temperature resistant alloy.

[0010] Preferably, the thermal expansion coefficient of the sealant is smaller than the thermal expansion coefficient of the housing.

[0011] Preferably, the difference between the thermal expansion coefficient of the sealant and the thermal expansion coefficients of the insulator and the stamped insulator is not greater than a set value.

[0012] Preferably, the insulator has threads at positions corresponding to the sealant.

[0013] The advantages of the present application include: the present application solves the problem of excessive air leakage after the ignition nozzle is used, the surface of the sealant is threaded after dissection, the product reliability is improved, and it has good economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the sealing structure of an aviation ignition nozzle according to a preferred embodiment of the present application;

[0015] Figure 2 It is a schematic diagram of a shell of a preferred embodiment of the present application. DETAILED DESCRIPTION

[0016] 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.

[0017] 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.

[0018] like Figure 1-Figure 2 As shown, the present application provides an aviation ignition nozzle sealing structure, comprising:

[0019] Stamping insulator 1, sealant 2, insulator 3, bushing 4 and housing 5;

[0020] The insulator 3 is sleeved in the cylindrical shell 5 through the bushing 4. The bushing 4 is pressed and fitted with the inner wall of the shell 5. The insulator 3 and the inner cylindrical surface of the shell 5 form a gap due to the diameter difference. At the position of the gap, the inner cylindrical surface of the shell 5 has an internal thread. The gap is filled with molten sealant 2, and the sealant 2 is axially extruded by the annular stamping insulator 1 so that the sealant 2 fills the gap. The insulator 3 includes a cylindrical section and a tapered section formed by gradually increasing the diameter of the end. The middle section of the bushing 4 has a radially inward boss. The inner wall surface of the bushing 4 has a tapered surface. The tapered surface of the bushing 4 fits with the tapered surface of the tapered section of the insulator 3. The diameter of the cylindrical section of the insulator 3 is smaller than the inner diameter of the shell 5. The inner cylindrical surface of the shell 5 has an internal thread. The sealing principle is: when the engine is working, the discharge end of the ignition nozzle is in the oil and gas mixture in the engine combustion chamber, in order to improve the sealing effect of the ignition nozzle. Adding threads to the metal shell at the sealing position increases the sealing contact area and improves the sealing effect. When cracks appear in the sealant under vibration and impact, when the cracks expand to the thread boundary, the pinning effect caused by the threads prevents the cracks from expanding, thereby preventing the seal from failing.

[0021] Preferably, the insulator 3 and the stamped insulator 1 are both made of alumina ceramic materials, the shell 5 is a high temperature resistant alloy, and the thermal expansion coefficient of the sealant 2 is less than the thermal expansion coefficient of the shell 5. The difference between the thermal expansion coefficient of the sealant 2 and the thermal expansion coefficients of the insulator 3 and the stamped insulator 1 is not greater than the set value. When the aviation ignition nozzle sealing structure is sealed, the aviation ignition nozzle sealing structure is heated to a molten state of the sealant 2, and the sealant 2 is pressurized by the stamped insulator 1. After the pressurization is completed, it is cooled to room temperature to complete the sealing. The main principle of the sealing structure is that the sealant is in a molten state after heating, and a certain pressure is applied to the sealant by the stamped insulator while heating. Under the action of pressure, the sealant flows into the sealing gap. The thermal expansion coefficient of the sealant is similar to that of the alumina ceramic material, has good adhesion, and is easy to bond together; the thermal expansion coefficient of the sealant is different from that of the shell high temperature alloy material. Under heating and pressurization conditions, the sealant expands with the shell. When the sealant cools, the shell shrinks greatly, extruding the sealant, filling the gap between the contact surfaces, and forming a pressure seal.

[0022] Preferably, the insulator 3 has a thread at a position corresponding to the sealant 2, which cooperates with the thread of the housing to improve the sealing performance.

[0023] The advantages of the present application include: the present application solves the problem of excessive air leakage after the ignition nozzle is used, the surface of the sealant is threaded after dissection, the product reliability is improved, and it has good economic and social benefits.

[0024] 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 sealing structure, characterized in that: include: Stamped insulator (1), sealant (2), insulator (3), bushing (4) and housing (5); The insulator (3) is sleeved in a cylindrical shell (5) through a bushing (4), the bushing (4) and the inner wall of the shell (5) are pressed and fitted, and a gap is formed between the insulator (3) and the inner cylindrical surface of the shell (5) due to the diameter difference. At the position of the gap, the inner cylindrical surface of the shell (5) has an internal thread, and the gap is filled with a molten sealant (2), and the sealant (2) is axially pressed by the annular stamping insulator (1) so that the sealant (2) fills the gap.

2. The aviation ignition nozzle sealing structure according to claim 1, characterized in that: The insulator (3) comprises a cylindrical section and a conical section whose end diameter gradually increases. The middle section of the bushing (4) has a radially inward groove. The inner wall surface of the bushing (4) has a conical surface. The conical surface of the bushing (4) fits with the conical surface of the conical section of the insulator (3).

3. The aviation ignition nozzle sealing structure according to claim 2, characterized in that: The diameter of the cylindrical section of the insulator (3) is smaller than the inner diameter of the housing (5).

4. The aviation ignition nozzle sealing structure according to claim 2, characterized in that: When the aviation ignition nozzle sealing structure is sealed, the aviation ignition nozzle sealing structure is heated until the sealant (2) is molten, and the sealant (2) is pressurized by punching the insulator (1). After the pressurization is completed, the sealant is cooled to room temperature to complete the sealing.

5. The aviation ignition nozzle sealing structure according to claim 2, characterized in that: The insulator (3) and the stamped insulator (1) are both made of alumina ceramic materials, and the shell (5) is made of high-temperature resistant alloy.

6. The aviation ignition nozzle sealing structure according to claim 2, characterized in that: The thermal expansion coefficient of the sealant (2) is smaller than the thermal expansion coefficient of the housing (5).

7. The aviation ignition nozzle sealing structure according to claim 2, characterized in that: The difference between the thermal expansion coefficient of the sealant (2) and the thermal expansion coefficients of the insulator (3) and the stamped insulator (1) is not greater than a set value.

8. The aviation ignition nozzle sealing structure according to claim 2, characterized in that: The insulator (3) has threads at positions corresponding to the sealant (2).

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