Lightning-resistant fastener, cap, and method of mounting lightning-resistant fastener

Patent metadata

Field	Value
Publication number	US-9334065-B2
Application number	US-201313939893-A
Country	US
Kind code	B2
Filing date	Jul 11, 2013
Priority date	Apr 2, 2009
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

There are provided a lightning-resistant fastener and a cap, which, while assuring sufficient insulation properties, provide improved workability and highly stable quality to thereby enable a reduction in the manufacturing cost of an airframe, and a method of mounting the lightning-resistant fastener. A hole 32 is formed in a cap 30 , and a screw groove 32 a is formed in the hole 32 . The configuration enables the cap 30 to be reliably and easily positioned and installed on a fastener member 24 and reliably prevents the cap 30 from coming off after the installation thereof. This improves the workability to reduce the production cost while assuring sufficient insulation properties and enables the cap 30 to be installed with stable quality irrespective of workers. Preferably, the cap 30 is made of a resin in view of mass producibility, weight reduction, and the like.

First claim

The invention claimed is:

1. A lightning-resistant fastener comprising:
a fastener main body, which penetrates through a first member and a second member, and projects on a side of the second member, the first member constituting an airframe of an aircraft and the second member being located on an interior side of the airframe,
a collar, which is mounted on the fastener main body and fastens the second member to the first member, and
a cap for covering the fastener main body and the collar on the side of the second member, the cap being made of an insulating material, the cap including:
a bottomed hole formed on an inner peripheral surface of the cap, the bottomed hole for receiving a front end part of the fastener main body,
a groove formed at least at one place on an inner peripheral surface of the bottomed hole of the cap, the groove extending parallel to a center axis of the bottomed hole, and
a thickness of a top of the cap is larger than a thickness of a part of the cap that is formed on an opening end side of the cap that faces the second member,
wherein the cap is filled with an insulating sealant, and

wherein the fastener main body comprises a screw groove, the screw groove projecting from the collar to contact the insulating sealant.

2. The lightning-resistant fastener according to claim 1 , wherein the second member is made of a metallic material.

3. The lightning-resistant fastener according to claim 1 , further comprising a washer which is held between the second member and the collar.

4. The lightning-resistant fastener according to claim 3 , wherein the washer is made of an insulating material.

5. The lightning-resistant fastener according to claim 1 , wherein the fastener main body is made of a metallic material, and the collar is made of a metallic material.

6. The lightning-resistant fastener according to claim 1 , wherein the collar comprises, on an outer peripheral surface thereof, a step part or a flange part projecting toward an outer periphery side of the collar.

7. The lightning-resistant fastener according to claim 1 , wherein the fastener main body is made of a metallic material, and a surface of the fastener main body is coated with an insulating material.

8. An aircraft comprising the lightning-resistant fastener according to claim 1 .

9. The aircraft according to claim 8 , wherein the first member is a wing panel.

10. The aircraft according to claim 8 , wherein the first member is made of CFRP (Carbon Fiber Reinforced Plastics) and the fastener main body is made of a metallic material, and
a rear end portion of the fastener main body is covered with a paint film which is formed on a surface of the first member.

11. The aircraft according to claim 10 , wherein the paint film is made of a paint containing copper.

12. A method of mounting a lightning-resistant fastener, comprising the steps of:
causing a fastener main body with a screw groove to penetrate through a first member constituting an airframe of an aircraft and a second member attached to the first member on an interior side of the airframe from an outer side of the airframe in a state in which the first member and the second member are laid on each other;
mounting a collar on the fastener main body from an interior side of the airframe so as to project the screw groove of the fastener main body from the collar; and
mounting a cap made of an insulating material so as to cover the fastener main body and the collar, wherein the cap is mounted in a state that the cap is filled with an uncured insulating sealant and thereby the screw groove projecting from the collar contacts the sealant,
wherein the cap comprises, on an inner peripheral surface of the cap, a bottomed hole for receiving a front end part of the fastener main body,
a groove extending along a center axis direction of the hole is formed at least at one place in an inner peripheral surface of the hole of the cap, and
a thickness of a top of the cap is larger than a thickness of a part of the cap, the part is formed on an opening end side of the cap so as to face the second member.

13. The method according to claim 12 , wherein the cap is mounted so that a one end part of the cap is in contact with a surface of the second member.

14. The method according to claim 12 , wherein the collar is mounted on the fastener main body after a washer is mounted on the fastener main body from the interior side of the airframe.

15. The method according to claim 14 , wherein the washer is made of an insulating material.

Assignees

• Mitsubishi Aircraft Corp

Inventors

• Bessho Masahiro
• Nihimura Wataru
• Ishikawa Naomoto
• Kamino Yuichiro
• Nohara Toshikatsu
• Hashigami Toru
• Tsuzuki Tamaki

Classifications

• F16B39/021

  by injecting a settable material after the screwing down · CPC title

• F16B37/14

  Cap nuts; Nut caps or bolt caps · CPC title

• B64D45/02 Primary

  Lightning protectors; Static dischargers · CPC title

• Y10T29/49947

  by applying separate fastener · CPC title

• F16B39/01

  specially adapted to prevent loosening at extreme temperatures · CPC title