JPH05164121A - Screw for aircraft - Google Patents

Abstract

PURPOSE:To provide simply and surely radio wave absorbing performance by inserting a tool into a hole provided in the top of a screw, lowering a fitting part in the hole against a spring to attach removably the screw while sticking an electric wave absorbing material respectively on the upper surfaces of the top and fitting part of the screw. CONSTITUTION:A screw body 1 is provided in the center of the screw top 2 with a hexagonal hole 3. Also, a fitting part 5 is received through a spring 4 in the hole 3. Further, an electric wave absorbing material is stuck on the upper surfaces of the screw top 2 and fitting part 5 respectively. When a force is not applied to the fitting part 5, the length of the spring 4 is set such that the respective upper surfaces of the screw top 2 and fitting part 5 are flush with each other. In attaching removably the screw, a hexagonal wrench 7 is pushed against the fitting part 5. Then, the spring 4 is contracted and the fitting part 5 is lowered to enable tightening and removal of the screw. Thereafter, when the hexagonal wrench 7 is removed, the spring 4 returns to the original length, and the respective upper surfaces of the screw top 2 and fitting part 5 are flush with each other to reduce radio wave reflection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw used outside the body of an aircraft, and is applicable to vehicles, ships and the like.

[0002]

2. Description of the Related Art An example of a conventional aircraft screw is shown in FIG.
The top 02 of the screw body 01 is provided with a groove 03 adapted to a tightening tool. The surface of the screw top 02 is metal,
No measures have been taken to reduce radio wave reflection.

FIG. 10 shows an example of using a conventional aircraft screw. The aircraft skin 05 is fixed to the aircraft structural member 04 with screws 01. On the surface of the aircraft outer plate 05, a sheet-shaped electromagnetic wave absorbing material 06 is attached in order to reduce reflection of electromagnetic waves. The surface of the screw top 02 is covered with a putty 07 made of a radio wave absorbing material in order to prevent radio wave reflection in the groove 03.

[0004]

The conventional aircraft screws have the following problems. (1) No measures have been taken to reduce radio wave reflection on the screw top, and if it is used outside the aircraft as it is, it will be easily caught by threat radar.

(2) If the screw top is covered with an electromagnetic wave absorbing putty in order to avoid the problem of the above (1), it becomes necessary to remove the putty every time it is removed, and the maintainability is deteriorated.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art by making the fitting portion, which is fitted inside the screw and provided with the movable mechanism, and the screw top be flat except when attaching and detaching,
Moreover, it is an aircraft screw in which a radio wave absorbing material is attached to the fitting portion and the screw top.

[0007]

The screw of the present invention has a flat top and a radio wave absorber is attached to the surface thereof. Therefore, when used on the surface of an aircraft, the screw is less likely to reflect radio waves than a conventional screw and is captured by a radar. Risk of Further, unlike the conventional method, since it is not necessary to use the electromagnetic wave absorbing putty, the maintainability when attaching and detaching the screw is high.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. In FIGS. 1 and 2, a hexagonal hole 3 is formed in the screw body 1 from the center of a screw top portion 2, and a fitting portion 5 is housed inside the hexagonal hole 3 via a spring 4. A radio wave absorbing material 6 is attached to the upper surfaces of the screw top portion 2 and the fitting portion 5. The length of the spring 4 is determined so that the screw top portion 2 and the upper surface of the fitting portion 5 are flush with each other when no force is applied to the fitting portion 5.

When the screw is attached or detached, as shown in FIGS. 3 and 4, when the hexagon wrench 7 is pressed against the fitting portion 5,
The force applied to the fitting portion 5 causes the spring 4 to contract, and the fitting portion 5 descends and is tightened to enable removal. When the hexagon wrench 7 is removed after the attachment / detachment work is completed, the spring 4 returns to its original length, the upper surfaces of the screw top portion 2 and the fitting portion 5 return to the same plane, and the radio wave reflection can be reduced.

A second embodiment of the present invention will be described with reference to FIGS. In FIGS. 5 and 6, a hemispherical recess 13 is provided at the center of the screw top portion 12 of the screw body 11, and the hemispherical fitting portion 14 is accommodated therein. Fitting part 14
A groove 16 for fitting the screwdriver 15 is engraved therein. The fitting portion 14 and the screw top portion 12 are connected as shown by a pin 17 having sufficient rigidity to withstand the torque at the time of tightening, and the fitting portion 14 can be rotated about the pin 17. . A radio wave absorbing material 18 is attached to the upper surface of the screw top portion 12 and the flat surface side of the fitting portion 14, and the upper surfaces of the screw top portion 12 and the fitting portion 14 are flush with each other.

When attaching or detaching the screw, as shown in FIGS. 7 and 8, the hemispherical side of the fitting portion 14 is directed upward, and the screwdriver 15 is inserted into the groove 16 to perform the same operation as a normal screw. When the attachment / detachment is completed, the fitting portion 14 is rotated around the pin 17 by 180 ° so that the plane side faces upward. In this state, since the upper surface side of the screw top portion 12 and the flat surface side of the fitting portion 14 are flush with each other and the radio wave absorbing material 18 is attached, even when used on the surface of the aircraft body,
Radio reflection is reduced compared to conventional screws, and the possibility of being caught by threat radar is reduced.

[0012]

EFFECTS OF THE INVENTION Since the present invention has the above structure, (1) the radio wave reflection at the screw crests on the surface of an aircraft is reduced, thereby reducing the risk of capturing by a threat radar. (2) The use of electromagnetic wave absorbing putty is unnecessary, and the maintainability of screw attachment / detachment is improved. Excellent effects such as

[Brief description of drawings]

FIG. 1 is a perspective view of the overall configuration according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of FIG.

FIG. 3 is a perspective view of FIG. 1 when attached and detached.

4 is a vertical cross-sectional view of FIG.

FIG. 5 is a perspective view of an overall configuration according to a second embodiment of the present invention.

FIG. 6 is a vertical cross-sectional view of FIG.

FIG. 7 is a perspective view of FIG. 5 at the time of attachment / detachment.

FIG. 8 is a vertical cross-sectional view of FIG.

FIG. 9 is a perspective view of the entire configuration showing a conventional aircraft screw.

10 is a vertical cross-sectional view showing the attached state of FIG.

[Explanation of symbols]

 1, 11 Screw body 2, 12 Screw top 3 Hole 4 Spring 5, 14 Fitting part 6, 18 Electromagnetic wave absorbing material 7 Hexagon wrench 13 Recess 15 Screw turning 16 Groove 17 Pin

Claims (1)

[Claims] 1. A fitting part, which is fitted inside a screw and provided with a movable mechanism, and a screw top are made flat except when attached and detached, and an electromagnetic wave absorbing material is attached to the fitting part and the screw top. An aircraft screw characterized by the above.