Anti-loosening structure for aircraft engine ignition cable

Abstract

The present application belongs to the field of ignition cable structure design, and particularly relates to an anti-loosening structure of an aircraft engine ignition cable, comprising: an insulator 1, a baffle 2, a bushing 3, a spring 4, a washer 5, a nut 6 and an upper shell 7 of an electric nozzle; the nut 6 comprises a threaded section and a straight section, the inner diameter of the threaded section is smaller than the inner diameter of the straight section; the inner diameter difference between the threaded section and the straight section forms a first step surface; the baffle 2 is welded at the outlet of the straight section to form a second step surface; the bushing 3 and the washer 5 are sleeved in the straight section of the nut 6, the annular limiting edge extending radially outward at the end face of the bushing 3 is axially limited by the second step surface, the washer 5 is axially limited by the first step surface, the spring 4 in a compressed state is located between the bushing 3 and the washer 5, and the insulator 1 is fixedly sleeved in the bushing 3; the external thread of the upper shell 7 of the electric nozzle is connected to the threaded section of the nut 6, and when the axial position of the end face of the upper shell 7 of the electric nozzle exceeds the first step surface, the spring 4 is further compressed and provides an axial preload force to the upper shell 7 of the electric nozzle through the washer 5.

Description

Technical Field

[0001] The present application belongs to the field of ignition cable structure design, and in particular relates to an anti-loosening structure of an aircraft engine ignition cable. Background Art

[0002] At present, the connection end structure of the ignition cable and the ignition nozzle is mainly composed of a core rod, an insulator, a bushing and a nut, and the ignition cable and the ignition nozzle are connected by threads. The principle is as follows: the ignition cable nut is connected to the upper shell of the ignition nozzle by threads. After the pin of the ignition nozzle is inserted into the ignition cable core rod, the ignition cable nut is further tightened until the insulator of the ignition cable contacts the upper shell of the ignition nozzle, and the tightening process is completed. The threaded connection ensures the reliability of the connection between the ignition cable and the ignition nozzle.

[0003] The ignition cable and the ignition nozzle are connected by threads. When the ignition cable and the ignition nozzle are used in a turboshaft engine with limited space and no fuse is used after the threaded connection, the ignition cable nut and the upper shell of the ignition nozzle will have a slight displacement in the vibration direction when the ignition cable and the ignition nozzle vibrate with the engine, resulting in a decrease in the friction between the thread pairs, which in turn causes the threads to loosen and the product cannot be reliably connected. Summary of the invention

[0004] In order to solve the above problems, the present application provides an aircraft engine ignition cable anti-loosening structure, comprising:

[0005] Insulator, baffle, bushing, spring, washer, nut and nozzle upper housing;

[0006] The nut includes a threaded section and a straight section, the inner diameter of the threaded section is smaller than the inner diameter of the straight section; the difference in inner diameter between the threaded section and the straight section forms a first step surface; the baffle is welded at the outlet of the straight section to form a second step surface; the bushing and the washer are sleeved in the straight section of the nut, the annular limiting edge extending radially outward at the end face of the bushing is axially limited by the second step surface, the washer is axially limited by the first step surface, the spring in a compressed state is located between the bushing and the washer, and the insulator is fixedly sleeved in the bushing; the external thread of the upper shell of the nozzle is connected to the threaded section of the nut, and when the axial position of the end face of the upper shell of the nozzle exceeds the first step surface, the spring is further compressed and provides axial preload to the upper shell of the nozzle through the washer. Preferably, there is a conical boss on the insulator, and the conical boss is squeezed into and fixed in the pit of the bushing.

[0007] Preferably, the insulator partially passes through the inner hole of the gasket.

[0008] Preferably, a wave-breaking ring is installed at the end surface of the upper shell of the nozzle, and the wave-breaking ring is in contact with the gasket.

[0009] Preferably, the nut material is 1Cr18Ni9Ti stainless steel.

[0010] Preferably, the material of the spring is 3J21 elastic alloy wire.

[0011] The advantages of the present application include: under the premise of ensuring that the spatial dimensions of the ignition cable remain unchanged, a compression spring structure is added to the ignition cable, ensuring that after the ignition cable is connected to the ignition nozzle, an axial force is provided by the compression spring, thereby increasing the friction between the threaded pairs and improving the anti-loosening performance of the threaded connection structure between the ignition cable and the ignition nozzle under mechanical environments such as vibration, impact, and acceleration. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of a nut in a preferred embodiment of the present application;

[0013] Figure 2 This is a schematic diagram of a spring in a preferred embodiment of the present application;

[0014] Figure 3 This is a schematic diagram of an insulator in a preferred embodiment of the present application;

[0015] Figure 4 This is a schematic diagram of a bushing in a preferred embodiment of the present application;

[0016] Figure 5 This is a schematic diagram of a baffle in a preferred embodiment of the present application;

[0017] Figure 6 This is a schematic diagram of a gasket in a preferred embodiment of the present application;

[0018] Figure 7 This is a schematic diagram of the connection structure between a nut and an insulator in a preferred embodiment of the present application;

[0019] Figure 8 It is a schematic diagram of the overall structure of the ignition cable anti-loosening according to a preferred embodiment of the present application. DETAILED DESCRIPTION

[0020] 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.

[0021] 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.

[0022] The present application provides an aircraft engine ignition cable loosening prevention structure, comprising:

[0023] Insulator 1, baffle 2, bushing 3, spring 4, washer 5, nut 6 and nozzle upper housing 7;

[0024] The nut 6 includes a threaded section and a straight section, the inner diameter of the threaded section is smaller than the inner diameter of the straight section; the difference in inner diameter between the threaded section and the straight section forms a first step surface; the baffle 2 is welded at the outlet of the straight section to form a second step surface; the bushing 3 and the washer 5 are sleeved in the straight section of the nut 6, and the annular limiting edge extending radially outward at the end face of the bushing 3 is axially limited by the second step surface, and the washer 5 is axially limited by the first step surface. The spring 4 in a compressed state is located between the bushing 3 and the washer 5, and the insulator 1 is fixedly sleeved in the bushing 3; the external thread of the upper shell 7 of the nozzle is connected to the threaded section of the nut 6. When the axial position of the end face of the upper shell 7 of the nozzle exceeds the first step surface, the spring 4 is further compressed and provides axial preload to the upper shell 7 of the nozzle through the washer 5.

[0025] Specifically, the nut 6 (see Figure 1 ): The material is 1Cr18Ni9Ti stainless steel, nut 6 and baffle 2 (see Figure 5 ) is matched, and the inner diameter of the straight section of the nut 6 is The outer diameter of the baffle 2 is 17 mm, and the two are matched with a clearance fit. The baffle 2 is stuck on the first step surface at the bottom of the straight section of the nut 6. Washer 5 (see Figure 6 ) is connected to the nut 6 by 6 laser spot welding to form a split nut 6 structure.

[0026] Spring 4 (see Figure 2 ): The material is 3J21 elastic alloy wire, with an outer diameter of 10.8mm and a wire diameter of 1.2mm. One end is pressed against a baffle 2 with an inner diameter of 7mm and an outer diameter of 17mm (see Figure 5 ) on the other end; the other end is on the inner diameter of 8.4mm, the outer diameter of 14.5mm bushing 3 ( Figure 4 )superior.

[0027] Insulator 1( Figure 3 ): The material is SFBN-1 polytetrafluoroethylene, and the length of the insulator 1 is The conical boss with an angle of 60° is squeezed into the bushing 3 ( Figure 4 ) length is The insulator 1 Ф6.5mm is inserted into the baffle 2 (see Figure 5 )In the inner hole of 7mm.

[0028] Bushing 3 (see Figure 4 ): The outer diameter of the bushing 3 is 14.5 mm, which is stuck inside the split nut 6. The washer 5 in the split nut 6 (see Figure 6 )The inner diameter is Ф13mm.

[0029] Principle: In order to ensure the anti-loosening performance of the threaded connection structure between the ignition cable and the ignition nozzle under the condition of limited space size, a spring 4 structure is added at the straight section of the ignition cable nut 6 to provide axial force for the connection end between the ignition cable and the ignition nozzle, increase the friction between the thread pairs, and when the thread produces slight vibrations under vibration conditions, the spring 4 provides axial force for compensation. First, select a split nut 6, which is welded by a washer 5 and a nut 6; secondly, increase the height of the straight section of the nut 6 to facilitate the installation of the spring 4 within the effective space size; support the spring 4 by adding a baffle 2 at the bottom of the straight section of the nut 6; the spring 4 is in a compressed state when the split nut 6 is installed, and part of the spring 4 elastic force is stored by the welding structure of the split nut 6. When the end of the ignition nozzle (upper shell, wave-breaking ring 8) squeezes the baffle 2, the spring 4 is further compressed, providing an axial force for the threaded connection structure between the ignition cable and the ignition nozzle, increasing the friction between the thread pairs, and thus ensuring the anti-loosening performance of the product. See the anti-loosening structure of the ignition cable. Figure 7 , the connection structure between the ignition cable and the ignition nozzle is shown in Figure 8 .

[0030] The advantages of the present application include: under the premise of ensuring that the spatial dimensions of the ignition cable remain unchanged, a compression spring structure is added to the ignition cable, ensuring that after the ignition cable is connected to the ignition nozzle, an axial force is provided by the compression spring, thereby increasing the friction between the threaded pairs and improving the anti-loosening performance of the threaded connection structure between the ignition cable and the ignition nozzle under mechanical environments such as vibration, impact, and acceleration.

[0031] 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 anti-loosening structure for an aircraft engine ignition cable, characterized in that: include: An insulator (1), a baffle (2), a bushing (3), a spring (4), a washer (5), a nut (6) and an upper housing (7) of the nozzle; The nut (6) comprises a threaded section and a straight section, the inner diameter of the threaded section is smaller than the inner diameter of the straight section; the difference between the inner diameters of the threaded section and the straight section forms a first step surface; the baffle (2) is welded at the outlet of the straight section to form a second step surface; the bushing (3) and the washer (5) are sleeved in the straight section of the nut (6); the annular limiting edge extending radially outward at the end face of the bushing (3) is axially limited by the second step surface, the washer (5) is axially limited by the first step surface, the spring (4) in a compressed state is located between the bushing (3) and the washer (5), and the insulator (1) is fixedly sleeved in the bushing (3); the external thread of the nozzle upper shell (7) is connected to the threaded section of the nut (6); when the axial position of the end face of the nozzle upper shell (7) exceeds the first step surface, the spring (4) is further compressed and provides an axial preload force to the nozzle upper shell (7) through the washer (5).

2. The anti-loosening structure of the aircraft engine ignition cable according to claim 1, characterized in that: The insulator (1) is provided with a conical boss, which is squeezed into and fixed in a recess of the bushing by extrusion.

3. The anti-loosening structure of the aircraft engine ignition cable according to claim 1, characterized in that: The insulator (1) partially passes through the inner hole of the gasket (5).

4. The anti-loosening structure of the aircraft engine ignition cable according to claim 1, characterized in that: A wave-breaking ring (8) is installed at the end surface of the upper shell (7) of the nozzle, and the wave-breaking ring (8) is in contact with the gasket (5).

5. The anti-loosening structure of the aircraft engine ignition cable according to claim 1, characterized in that: The material of the nut (6) is 1Cr18Ni9Ti stainless steel.

6. The anti-loosening structure of the aircraft engine ignition cable according to claim 1, characterized in that: The material of the spring (4) is selected from 3J21 elastic alloy wire.

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