LIGHTNING-RESISTANT FASTENER AND MOUNTING STRUCTURE OF LIGHTNING-RESISTANT FASTENER

• US 20120155987A1
• Filed: 12/07/2011
• Published: 06/21/2012
• Est. Priority Date: 12/17/2010
• Status: Active Grant

• Current Assignee: Mitsubishi Aircraft Corporation (Mitsubishi Heavy Industries, Ltd.)
• Original Assignee: Mitsubishi Aircraft Corporation (Mitsubishi Heavy Industries, Ltd.)
• Inventors: Watanabe, Yasunori
• Granted Patent: US 8,882,423 B2
• Time in Patent Office: Days
• US Class Current: 411/337
• CPC Class Codes: B64D 45/02 Lightning protectors; Static dischargers in general H01T
• CPC Class Codes: F16B 37/14 Cap nuts; Nut caps or bolt caps

Abstract

To provide a lightning-resistant fastener capable of assuring a sufficient lightning-resistant performance. A cap 30A has an elastically deformable part 50 continuous in the circumferential direction thereof. The elastically deformable part 50 has a smaller thickness than the other parts of the cap 30A in a circumferentially continuous area thereof. Since the cap 30A has the elastically deformable part 50, even if a surface 22b of a member 22 is inclined with respect to a plane perpendicular to the axis of a fastener main body 25, the cap 30A can be installed without forming a gap.

Claims

1. A lightning-resistant fastener comprising:

a fastener member used for fastening a second member to a first member constituting an airframe of an aircraft, the fastener member being made of a conductive material; and

a cap installed so as to cover the fastener member projecting to the interior side of the airframe, the cap being made of an insulating material, wherein

the fastener member has an engaging part in a portion projecting to the interior side of the airframe,

the cap has an engaged part to be engaged with the engaging part of the fastener member in a central portion of the inner peripheral surface of the cap, the cap being installed to the fastener member with the engaged part being engaged with the engaging part of the fastener member, a tip end part of the cap opposite to the engaged part abutting against the second member, and a gap being provided between the fastener member and a portion of the cap other than the engaged part, and

an elastically deformable part is provided to allow the cap to be elastically deformed in the direction to compress the cap between the engaged part and the tip end part abutting against the second member while the engaged part is engaged with the engaging part.

2. The lightning-resistant fastener according to claim 1, wherein, as the elastically deformable part, the cap has a part continuous in the circumferential direction of the cap having a smaller thickness than another part formed between the engaged part and the tip end part or at the tip end part.

3. The lightning-resistant fastener according to claim 1, wherein an annular seal member continuous in the circumferential direction of the cap is provided on the abutment surface between the tip end part of the cap and the second member.

4. A structure for mounting a lightning-resistant fastener comprising:

a fastener member used for fastening a second member to a first member constituting an airframe of an aircraft, the fastener member being made of a conductive material; and

a cap having one open end opening at one end and installed so as to cover the fastener member projecting to the interior side of the airframe, the cap being made of an insulating material, wherein

a recess is formed in a surface of the second member, and

the cap is installed with the open end being housed in the recess formed in the second member.

5. The structure for mounting a lightning-resistant fastener according to claim 4, wherein the outer peripheral surface of the open end of the cap has a polygonal cross section in the direction perpendicular to the axis of the fastener member, and

the inner peripheral surface of the recess includes an opposing surface that is opposite to the outer peripheral surface of the open end having the polygonal cross section.

6. The structure for mounting a lightning-resistant fastener according to claim 4, wherein the outer peripheral surface of the open end of the cap has a circular cross section in the direction perpendicular to the axis of the fastener member, and

the recess has a circular shape, and the inner peripheral surface of the recess includes an opposing surface that is opposite to the outer peripheral surface of the open end.

7. The structure for mounting a lightning-resistant fastener according to claim 4, wherein an annular seal member continuous in the circumferential direction of the cap is provided on the abutment surface between the tip end part of the cap and the second member.

8. The structure for mounting a lightning-resistant fastener according to claim 6, wherein a screw groove is formed in the outer peripheral surface of the open end of the cap, a screw groove to be engaged with the screw groove of the open end is formed in the inner peripheral surface of the recess, and the cap is installed by screwing the open end of the cap into the recess.

9. The structure for mounting a lightning-resistant fastener according to claim 4, wherein a mark that indicates the amount of a sealant charged into the cap is formed on the inner peripheral surface of the cap.