Concave gasket for lightning electrostatic protection, mounting node based on concave gasket and airplane

Abstract

The utility model belongs to the field of airplane structure design, and discloses a concave gasket for lightning electrostatic protection, a mounting node based on the concave gasket and an airplane, the concave gasket comprises a circular truncated cone inner ring, the outer edge of the large end of the circular truncated cone inner ring is coaxially provided with a convex shoulder, the convex shoulder is in a circular truncated cone shape, and the small end of the convex shoulder is connected with the large end of the circular truncated cone inner ring; the large end of the shoulder inclines towards the small end of the circular truncated cone inner ring, and the corner of the joint of the circular truncated cone inner ring and the shoulder is arc-shaped. After the concave gasket is installed, the convex shoulder can be tightly attached to the surface of a fastening material all the time, the tight electrical connection state between the whole concave gasket and a metal layer on the surface of a composite material wall plate is achieved, and then stable and reliable electrical connection between a sunk screw and the metal layer is achieved. Therefore, the lightning protection requirement of the composite material wall plate and the static conduction requirement of an airplane structure can be met, and the structure is simple and reasonable.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of aircraft structure design, and relates to a recessed washer for lightning electrostatic protection and mounting node and aircraft based on it. BACKGROUND

[0002] In prior art, because composite material structure has the advantages of light weight, high specific strength, good fatigue resistance and good designability, now wing surface wall plate adopts composite material structure, but aircraft wing surface is mostly in lightning area, and the conductivity of composite material wall plate is poor, therefore, the composite material wall plate usually adopts an outer surface to be covered with a conductive layer to provide a lightning current channel of conductive protection system, however, because the composite material wall plate is connected by drilling, many connecting holes are formed in the conductive layer on the surface of the composite material wall plate, and the lightning current will produce discharge phenomenon due to the potential difference around the connecting holes of the conductive layer, and the discharge phenomenon will burn the composite material wall plate, or even cause catastrophic consequences due to structure connection failure.

[0003] The composite material wall plate is mostly connected by two connection forms of protruding head nails and countersunk nails. The protruding head nail connection form can utilize the lower surface of the nail head to lap and conduct current with the conductive layer to meet the lightning protection requirement, but because the fastener nail head protrudes from the aerodynamic surface, the surface quality of the composite material wall plate is affected, and the aerodynamic characteristics are reduced, and the weight is much heavier than that of the countersunk nail connection form. The countersunk nail connection form has the advantages of light weight and good aerodynamic characteristics, but because of the dimple of the nail hole of the composite material wall plate, the current circuit between the conductive layer and the countersunk nail is broken, and when the lightning current adheres or sweeps the surface of the composite material wall plate, the discharge often occurs at the fastener, which causes the composite material wall plate to be ablated and the fastener connection to be invalid, and further affects the flight safety.

[0004] The technical problem to be solved at present is to design a simple and reasonable structure and a dielectric functional element which are easy to maintain, can meet the aerodynamic characteristic requirement of the surface of the composite material wall plate, and can prevent the composite material wall plate from being damaged and the fastener connection from being invalid due to lightning current discharge. SUMMARY

[0005] The utility model aims at solving the above-mentioned defects in prior art, and provides a recessed washer for lightning electrostatic protection and mounting node and aircraft based on it, and the recessed washer of the utility model is a dielectric functional recessed washer which is simple and reasonable in structure, meets the lightning protection requirement of the composite material wall plate and the electrostatic conduction requirement of the aircraft structure.

[0006] The utility model aims at solving the above-mentioned defects in prior art, and provides a recessed washer for lightning electrostatic protection and mounting node and aircraft based on it, and the recessed washer of the utility model is a dielectric functional recessed washer which is simple and reasonable in structure, meets the lightning protection requirement of the composite material wall plate and the electrostatic conduction requirement of the aircraft structure.

[0007] The recessed washer for lightning electrostatic protection comprises a circular truncated cone inner ring, and a convex shoulder coaxially arranged on the outer edge of the large end of the circular truncated cone inner ring, wherein the convex shoulder is in the shape of a circular truncated cone, the small end of the convex shoulder is connected with the large end of the circular truncated cone inner ring, the large end of the convex shoulder is inclined towards the side of the small end of the circular truncated cone inner ring, and the corner at the connection between the circular truncated cone inner ring and the convex shoulder is in the shape of a circular arc.

[0008] Preferably, the angle between the side surface of the convex shoulder and the plane where the large end of the circular truncated cone inner ring is located is 4-6°.

[0009] Preferably, the top angle of the corresponding cone of the circular truncated cone inner ring is 99-101°.

[0010] Preferably, the corner is a circular arc surface, the radius of the corner is 1 mm, and the tolerance is HB 5800 general tolerance.

[0011] Preferably, the length of the side surface of the convex shoulder is 3-5 mm.

[0012] Preferably, the circular truncated cone inner ring and the convex shoulder are in an integrated structure, the material thickness of the circular truncated cone inner ring and the convex shoulder is 0.4 mm, and the tolerance is HB 5800 general tolerance.

[0013] The utility model also provides a kind of installation node for lightning electrostatic protection, including metal structural member, composite wallboard, sunk high lock bolt and the recessed washer for lightning electrostatic protection described above in the utility model, the composite wallboard is arranged on the surface of metal structural member, the surface of composite wallboard is also equipped with conducting layer, the sunk high lock bolt is threaded through the bolt hole on conducting layer, composite wallboard and metal structural member, recessed washer is set on sunk high lock bolt and is arranged in conducting layer side, the head of sunk high lock bolt is towards conducting layer side, the other end of sunk high lock bolt is threadedly cooperated and is connected with high lock nut, the convex shoulder of recessed washer is towards the head of sunk high lock bolt;When high lock nut and sunk high lock bolt fasten metal structural member and composite wallboard, the side surface of the convex shoulder of recessed washer is attached to conducting layer, and the small end of the circular truncated cone inner ring is attached to the head of sunk high lock bolt.

[0014] Preferably, the sunk high lock bolt adopts the shear type sunk high lock bolt of HST11 series, and the angle of the head of the shear type sunk high lock bolt is the same as the top angle of the corresponding cone of the circular truncated cone inner ring.

[0015] The utility model also provides an airplane, and the connecting node between the composite wallboard and the metal structural member on the wing surface of the airplane adopts the installation node described above in the utility model.

[0016] Preferably, in the structure after high lock nut and sunk high lock bolt fasten metal structural member and composite wallboard, the surface of conducting layer is provided with paint layer, and the paint layer covers the exposed surfaces of conducting layer, recessed washer and sunk high lock bolt.

[0017] The utility model has the advantages of the following:

[0018] Therefore, in use, the large end of the convex shoulder is inclined to the small end of the inner circle of the circular table, and the large end of the convex shoulder still has a tendency to incline to the small end of the inner circle of the circular table due to the elasticity of the recessed washer material, so the convex shoulder is always tightly attached to the surface of the fastening material (such as the metal layer on the surface of the composite wallboard), realizing a close electrical connection between the recessed washer and the metal layer on the surface of the composite wallboard, and at the same time, the inner circle of the circular table is also closely attached to the head of the countersunk screw, so the utility model can realize stable and reliable electrical connection between the countersunk screw and the metal layer, and the recessed washer of the utility model can meet the lightning protection requirements of the composite wallboard and the static electricity conduction requirements of the aircraft structure, and has a simple and reasonable structure. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structure diagram of the recessed washer for lightning static protection in the embodiment of the utility model;

[0020] Figure 2 is a longitudinal sectional view of the recessed washer for lightning static protection in the embodiment of the utility model;

[0021] Figure 3 is an application state diagram of the recessed washer for lightning static protection in the embodiment of the utility model.

[0022] Numbering in the figure: 1 - paint layer, 2 - countersunk high lock bolt, 3 - recessed washer, 3-1 - convex shoulder, 3-2 - corner, 3-3 - inner circle of circular table, 4 - conductive layer, 5 - composite wallboard, 6 - metal structural part, 7 - high lock nut. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described in the following with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. The components of the embodiments of the utility model described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the claimed utility model, but only represents selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the utility model.

[0024] Referring to Figure 1 and Figure 2 , the recessed washer for lightning electrostatic protection in the embodiment comprises a circular cone inner ring 3-3, an outer edge of a large end of the circular cone inner ring 3-3 is coaxially provided with a shoulder 3-1, the shoulder 3-1 is in the shape of a circular cone, a small end of the shoulder 3-1 is connected with the large end of the circular cone inner ring 3-3, a large end of the shoulder 3-1 is inclined towards a side of a small end of the circular cone inner ring 3-3, and a corner 3-2 at a connection between the circular cone inner ring 3-3 and the shoulder 3-1 is in the shape of a circular arc. Since the material of the recessed washer is generally metal, such as steel or other alloy materials, the recessed washer generally has elasticity, referring to Figure 3 , when the recessed washer of the utility model is in use, with the fastening of the countersunk head high lock bolt 2, the angle of the shoulder 3-1 and the circular cone inner ring 3-3 at the corner 3-2 will change, so that the lower surface of the shoulder 3-1 is tightly attached to the surface of the conductive layer 4. Since the recessed washer itself has a certain elasticity, the shoulder 3-1 will have a tendency to bend downward, so that the lower surface of the shoulder 3-1 is tightly attached to the surface of the conductive layer 4, and can withstand a certain vibration and thermal stress. Due to the existence of elasticity, the lower surface of the shoulder 3-1 will always be tightly attached to the surface of the conductive layer 4, thereby ensuring the electrical connection between the recessed washer and the conductive layer 4.

[0025] As a preferred embodiment of the utility model, referring to Figure 2 , in the embodiment, the included angle β between the side surface of the shoulder 3-1 and the plane where the large end of the circular cone inner ring 3-3 is located is 4°-6°. Under this angle, it can be ensured that the recessed washer is always in an elastic deformation state during use, thereby ensuring that the lower surface of the shoulder 3-1 is always tightly attached to the surface of the conductive layer 4.

[0026] As a preferred embodiment of the utility model, referring to Figure 2In the embodiment, the corner 3-2 is a circular arc surface, the radius of the corner 3-2 is 1 mm, and the tolerance is an HB 5800 general tolerance, and the corner structure is beneficial to ensure that the recessed gasket is always in an elastic deformation state during use.

[0027] Referring to Figure 3 In the embodiment, the recessed gasket 3 is used for lightning electrostatic protection, the recessed gasket 3 is sleeved on the countersunk high-lock bolt 2 and is arranged on one side of the conductive layer 4, the head of the countersunk high-lock bolt 2 is directed to one side of the conductive layer 4, the other end of the countersunk high-lock bolt 2 is threadedly connected with the high-lock nut 7, and the shoulder 3-1 of the recessed gasket 3 is directed to the head of the countersunk high-lock bolt 2.

[0028] As a preferred embodiment of the utility model, in the embodiment, the countersunk high-lock bolt 2 is an anti-shear countersunk high-lock bolt of an HST11 series, and the angle of the head of the anti-shear countersunk high-lock bolt is the same as the top angle of the corresponding cone of the circular truncated cone inner ring 3-3.

[0029] The embodiment also provides an airplane, and a connecting node between a composite material wall plate and a metal structural member on a wing surface of the airplane adopts the mounting node of the utility model.

[0030] As a preferred embodiment of the utility model, referring to Figure 3 In the embodiment, a paint layer 1 can also be arranged on the surface of the conductive layer 4, and the paint layer 1 covers the exposed surfaces of the conductive layer 4, the recessed gasket 3 and the countersunk high-lock bolt 2.

[0031] Embodiment

[0032] As Figure 1 shown, the recessed washer 3 of the present embodiment is provided with a shoulder 3-1, and the shoulder 3-1 has a certain width, so that there is a certain overlap area between the shoulder 3-1 and the conductive layer 4, and the shoulder 3-1 is used for conducting lightning current and static current, as shown in Figure 2 , the width A of the shoulder 3-1 is 3mm-5mm. As Figure 2 shown, when the axis of the recessed washer 3 is in a vertical state, the included angle β between the shoulder 3-1 and the horizontal plane is 5°±1°.

[0033] In the recessed washer 3 of the present embodiment, the inner circle of the circular truncated cone 3-3 and the shoulder 3-1 are integrally manufactured, and the recessed washer 3 is completely matched and fitted with the recessed area of the shear type 100° countersunk head high lock bolt head. The sectional parameters of the series of recessed washers are shown in the following table.

[0034] Table 1

[0035]

[0036] As Figure 3 shown, the recessed washer of the present embodiment is used for composite wall plate connecting structure, and the connecting node includes a metal structural part 6, a composite wall plate 5, a countersunk head high lock bolt 2 and a recessed washer 3. The composite wall plate 5 is arranged on the surface of the metal structural part 6, and the surface of the composite wall plate 5 is further provided with a conductive layer 4. The countersunk head high lock bolt 2 penetrates the bolt holes on the conductive layer 4, the composite wall plate 5 and the metal structural part 6, and the recessed washer 3 is sleeved on the countersunk head high lock bolt 2 and arranged on one side of the conductive layer 4. The head of the countersunk head high lock bolt 2 is directed to one side of the conductive layer 4, and the other end of the countersunk head high lock bolt 2 is threadedly connected with a high lock nut 7. The shoulder 3-1 of the recessed washer 3 is directed to the head of the countersunk head high lock bolt 2. When the high lock nut 7 and the countersunk head high lock bolt 2 fasten the metal structural part 6 and the composite wall plate 5, the side surface of the shoulder 3-1 of the recessed washer 3 is fitted with the conductive layer 4, and the small end of the inner circle of the circular truncated cone 3-3 is fitted with the head of the countersunk head high lock bolt 2. As can be seen, when the high lock nut 7 and the countersunk head high lock bolt 2 fasten the metal structural part 6 and the composite wall plate 5, the recessed washer 3 effectively realizes the electrical connection between the countersunk head high lock bolt 2, the recessed washer 3, the conductive layer 4 and the metal structural part 6. At the same time, a paint layer 1 is arranged on the surface of the conductive layer 4, and the paint layer 1 covers the exposed surfaces of the conductive layer 4, the recessed washer 3 and the countersunk head high lock bolt 2. In this node, lightning current and static current can be conducted through "copper mesh (i.e. conductive layer 4)→recessed washer→countersunk head high lock bolt 2→metal structural part 6", and vice versa.

[0037] In the prior art, the composite panel connection is mostly connected by two connection forms of protruding head nails and countersunk nails. The protruding head nail connection form can utilize the lower surface of the nail head to lap and conduct current with the conductive layer to meet the lightning protection requirements, but because the fastener nail head protrudes from the aerodynamic surface, it will affect the surface quality of the composite panel, thereby reducing the aerodynamic characteristics, and the weight is much heavier than that of the countersunk nail connection form. The countersunk nail connection form has the advantages of light weight and good aerodynamic characteristics, but because of the dimple of the composite panel nail hole, the current circuit between the conductive layer and the countersunk nail is caused, and when the lightning current adheres or sweeps the surface of the composite panel, the discharge often occurs at the fastener, causing the composite panel ablation and the fastener connection failure, thereby affecting the flight safety.

[0038] From the above scheme of the recessed washer for lightning electrostatic protection and the composite panel connection structure of the utility model can be seen, the utility model is provided with a recessed washer 3 between the high lock bolt 2 of the fastener and the conductive layer 4, which is used for connecting the current path between the conductive layer 4 and the high lock bolt 2, can meet the requirements of the surface quality and aerodynamic characteristics of the composite panel 5, prevent the damage of the composite panel 5 and the connection failure of the fastener caused by the discharge of lightning current, and meet the discharge requirement of the static electricity transmission of the aircraft structure to the discharge brush of the control surface. The structure is simple, easy to maintain and replace, has high structural stability, greatly reduces the structure lightning damage probability and structure maintenance cost.

[0039] The recessed washer for lightning electrostatic protection and the composite panel connection structure of the utility model are described in detail above, but this is not a limitation of the utility model, any simple modification of the above embodiments according to the technical essence of the utility model belongs to the technical scope of the utility model, and it should be noted that the technical scheme of the recessed washer for lightning electrostatic protection and the composite panel connection structure of the utility model includes any combination of the above parts, which should be covered in the protection scope of the claims of the utility model.

Claims

1. A recessed grommet for lightning electrostatic protection, characterized in that, The outer edge of the large end of the circular cone inner ring (3-3) is coaxially provided with a shoulder (3-1), the shape of the shoulder (3-1) is a circular cone, the small end of the shoulder (3-1) is connected with the large end of the circular cone inner ring (3-3), the large end of the shoulder (3-1) is inclined towards the small end of the circular cone inner ring (3-3), and the corner (3-2) at the connection between the circular cone inner ring (3-3) and the shoulder (3-1) is in a circular arc shape.

2. A recessed washer for lightning electrostatic protection according to claim 1, characterized in that, The angle between the side surface of the shoulder (3-1) and the plane where the large end of the circular cone inner ring (3-3) is located is 4°-6°.

3. A recessed washer for lightning electrostatic protection according to claim 1, characterized in that, The top angle of the corresponding cone of the circular cone inner ring (3-3) is 99°-101°.

4. A recessed washer for lightning electrostatic protection according to claim 1, characterized in that, The corner (3-2) is a circular arc surface, the radius of the corner (3-2) is 1mm, and the tolerance is HB 5800 general tolerance.

5. A recessed washer for lightning electrostatic protection according to claim 1, characterized in that, The length of the side surface of the shoulder (3-1) is 3-5mm.

6. A recessed washer for lightning electrostatic protection according to claim 1, characterized in that, The circular cone inner ring (3-3) and the shoulder (3-1) are an integral structure, the material thickness of the circular cone inner ring (3-3) and the shoulder (3-1) is 0.4mm, and the tolerance is HB 5800 general tolerance.

7. A mounting node for lightning electrostatic protection, characterized by, The recessed washer (3) is set on the sunken high-lock bolt (2) and is arranged on one side of the conductive layer (4), the head of the sunken high-lock bolt (2) is directed to one side of the conductive layer (4), the other end of the sunken high-lock bolt (2) is threadedly connected with a high-lock nut (7), and the shoulder (3-1) of the recessed washer (3) is directed to the head of the sunken high-lock bolt (2); after the high-lock nut (7) and the sunken high-lock bolt (2) fasten the metal structural member (6) and the composite material wall plate (5), the side surface of the shoulder (3-1) of the recessed washer (3) is attached to the conductive layer (4), and the small end of the circular cone inner ring (3-3) is attached to the head of the sunken high-lock bolt (2).

8. A mounting node for lightning electrostatic protection according to claim 7, characterized in that, The sunken high-lock bolt (2) is an anti-shear type sunken high-lock bolt of the HST11 series, and the angle of the head of the anti-shear type sunken high-lock bolt is the same as the top angle of the corresponding cone of the circular cone inner ring (3-3).

9. An aircraft, characterized in that The connecting joint between the composite material wall plate and the metal structural member on the airfoil of the aircraft adopts the mounting joint of claim 7 or 8.

10. An aircraft as claimed in claim 9, characterised in that In the structure after the high-lock nut (7) and the sunken high-lock bolt (2) fasten the metal structural member (6) and the composite material wall plate (5), a paint layer (1) is arranged on the surface of the conductive layer (4), and the paint layer (1) covers the exposed surfaces of the conductive layer (4), the recessed washer (3) and the sunken high-lock bolt (2).

Images