JP2021127803A - Fastening method - Google Patents

Abstract

To provide a fastening method capable of fastening a member such as fiber-reinforced plastic, aluminum and copper without damage.SOLUTION: [0007] A stud bolt 14 provided with a right screw portion 15 and a left screw portion 16 at both sides of a shaft, is penetrated through a first member 10 and a second member 11, a nut 18 for right screw and a nut 19 for left screw are fitted thereto, and then the stud bolt 14 is rotated; therefore, the first member 10 and the second member 11 are fastened without rotating the nuts. One of the nuts is a dish nut having a taper-shaped seating face, and the stud bolt is rotated by using a driving portion formed on its head portion while restricting rotation of the dish nut; therefore, the head portion of the dish nut can be fastened without projecting from a surface of the member.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fastening method capable of fastening a member without damaging it.

Fastening bolts and nuts to members made of fiber reinforced plastic (CFRP) and members such as aluminum and copper has been conventionally performed as described in Patent Document 1, for example. However, in normal bolt-nut fastening, the bolt or nut is rotated and tightened after the bolt is passed through the first member and the second member, so that the bearing surface of the bolt or nut touches the surface of the member at the final stage of fastening. There was a risk of injury. This problem is often negligible when the member is a hard metal, but cannot be ignored when the member is a fiber reinforced plastic, aluminum, copper or the like.

As one of the methods for avoiding this problem, as shown in FIGS. 3 and 4, a washer 1 having a flat portion on the outer periphery is used, and for example, a wrench 2 is used to tighten the bolt 3 while stopping the rotation of the washer 1. There is a way. However, especially when a bolt 3 with a flange as shown in the figure is used, a large torque of 60 to 70% of the tightening torque is applied to the washer 1 on the tightening side, so that the wall thickness of the washer 1 must be increased. There was a problem.

Further, particularly in the field of aircraft, it may be required that the head on the bolt tightening side does not protrude from the member surface, and in that case, a countersunk bolt 4 having a tapered seat surface as shown in FIG. 5 is used. Often. However, in the case of FIG. 5, as shown in FIG. 3, it is not possible to adopt a method of tightening the bolt while stopping the rotation of the washer, and it is inevitable that the tapered seat surface of the countersunk bolt 4 rotates. Therefore, there is a risk of damaging the member.

JP-A-2019-199920

Therefore, an object of the present invention is to solve the above-mentioned conventional problems and to provide a fastening method capable of fastening members such as fiber reinforced plastic, aluminum, and copper without damaging them.

In the fastening method of the present invention, which has been made to solve the above problems, a stud bolt having a right-hand threaded portion and a left-handed threaded portion formed on both sides of the shaft is passed through the first member and the second member, and the right-handed threaded portion is formed. By fitting the right-handed screw nut and the left-handed screw nut into the left-handed screw portion and then rotating the stud bolt, the first member and the second member can be fastened without rotating these nuts. It is a feature.

The stud bolt can be rotated while restricting the rotation of these nuts with a wrench or a jig. Further, the stud bolt can be rotated by using the drive unit formed on the head thereof. Further, one nut may be a countersunk nut having a tapered seating surface, and the stud bolt can be rotated by using a drive portion formed on the head of the countersunk nut while restricting the rotation of the countersunk nut.

According to the fastening method of the present invention, by rotating a stud bolt having a right-hand thread portion and a left-hand thread portion formed on both sides of the shaft, the right-hand thread nut and the left-hand thread nut are brought close to each other without rotation. The first member and the second member can be fastened. Therefore, even if the member is made of a material that is more easily scratched than a metal such as fiber reinforced plastic, aluminum, or copper, it can be fastened without being scratched.

In particular, at least one of the nuts is a countersunk nut having a tapered seating surface, and the stud bolt is rotated by using a drive portion formed on the head of the countersunk nut while restricting the rotation of the countersunk nut. It can be fastened without protruding the head of the member from the surface of the member and without rotating the countersunk nut.

It is a partial cross-sectional view which shows the 1st Embodiment of this invention. It is sectional drawing which shows the 2nd Embodiment of this invention. It is sectional drawing which shows the prior art. It is a top view of FIG. It is sectional drawing which shows the other prior art.

An embodiment of the present invention will be described below.
FIG. 1 is a partial cross-sectional view showing a first embodiment of the present invention. In the figure, 10 is the first member and 11 is the second member. Although these materials are not specified, in this embodiment, the first member 10 is a steel plate, and the second member 11 is a plate material made of fiber reinforced plastic (CFRP). Bolt insertion holes 12 and 13 are formed in these members.

Reference numeral 14 denotes a stud bolt inserted into the bolt insertion holes 12 and 13. The stud bolt 14 has a right-hand threaded portion 15 and a left-handed threaded portion 16 formed on both sides of the shaft, and the pitches of the right-handed threaded portion 15 and the left-handed threaded portion 16 are arbitrary, but are preferably the same. ..

In this embodiment, a drive unit 17 is formed on at least one head of the stud bolt 14. The structure of the drive unit 17 is not particularly limited, but in this embodiment, it has a hexagonal shape.

As shown in FIG. 1, a right-hand thread nut 18 is fitted into the right-hand thread portion 15, and a left-hand thread nut 19 is fitted into the left-hand thread portion 16. In this embodiment, these nuts are flanged nuts. Then, when the stud bolt 14 is rotated clockwise (rightward) when viewed from the upper surface by using the drive unit 17, the right-hand thread nut 18 moves toward the fastening member 10, and the left-hand thread nut 19 It moves toward the member to be fastened 11.

At this time, these nuts do not need to be rotated, and at the final stage of fastening, they come into contact with the first member 10 and the second member 11, so that they do not rotate due to the frictional force of the seat surface. However, since these nuts may rotate together with the stud bolt 14 at the initial stage of fastening, the stud bolt 14 is rotated while restricting the rotation of the nut with a wrench 20, 21 or a jig as shown in FIG. Is desirable.

As described above, according to the fastening method of the present invention, the first member 10 and the second member 11 can be fastened without rotating the nut, so that the member is damaged by the rotation of the nut as in the conventional case. There is no. Therefore, even if the member is made of fiber reinforced plastic, which is more easily damaged than metal, it is possible to fasten with good appearance.

FIG. 2 is a cross-sectional view showing a second embodiment of the present invention. In the figure, 10 is the first member and 11 is the second member, but the upper portion of the bolt insertion hole 13 formed in the second member 11 is a tapered enlarged portion 30.

The stud bolt 14 used in the second embodiment also has a right-hand threaded portion 15 and a left-handed threaded portion 16 formed on both sides of the shaft, but a drive portion 31 is formed on the head of the shaft. The drive unit 31 has a concave shape and can be rotated by using a dedicated driver 32.

A right-handed screw nut 18 similar to that shown in FIG. 1 is fitted in the right-handed screw portion 15 of the stud bolt 14, but the left-handed screw portion 16 has a tapered seat corresponding to the tapered enlarged portion 30 as shown in the drawing. A countersunk nut 33 having a surface is fitted. The countersunk nut 33 is for a left-handed screw, and a detent recess 34 is formed on the top surface thereof.

If the stud bolt 14 is rotated while the detent tool 35 of the detent recess 34 is inserted to prevent the rotation, the countersunk nut 33 does not rotate and the tapered enlargement formed in the second member 11 is performed. It can move into the portion 30 and fasten the first member 10 and the second member 11. Further, since the head of the countersunk nut 33 can be fastened without protruding from the surface of the second member 11, it is particularly suitable for use in the aircraft field.

In these embodiments, the right-hand threaded portion 15 of the stud bolt 14 is used as the lower side, but it is also possible to use the stud bolt 14 upside down. However, in that case, the stud bolt 14 is fastened in the opposite direction of rotation.

In these embodiments, the hexagonal drive portions 17 and 31 are formed on the stud bolt 14, but the portion for rotating the stud bolt 14 is not limited to this shape, and if it is non-circular, It can have any shape such as a pentagonal column, a square column, a pentagonal hole, and a square hole.

The rotation of the stud bolt 14 is preferably performed from the surface side where the rotation of the nut is desired to be eliminated. This is because the operator can rotate the stud bolt 14 while looking at the nut.

As described above, according to the present invention, there is an advantage that members such as fiber reinforced plastic, aluminum, and copper can be fastened without being damaged by the rotation of the nut.

1 Washer 2 Wrench 3 Bolt 4 Countersunk bolt 10 1st member 11 2nd member 12 Bolt insertion hole 13 Bolt insertion hole 14 Stud bolt 15 Right-hand thread 16 Left-hand thread 17 Drive 18 Right-hand thread nut 19 Left-hand thread nut 20 Wrench 21 Wrench 30 Tapered expansion part 31 Drive part 32 Dedicated driver 33 Countersunk nut 34 Anti-rotation recess 35 Anti-rotation tool

Claims (4)

A stud bolt having a right-handed screw portion and a left-handed screw portion formed on both sides of the shaft is passed through the first member and the second member, and a right-handed screw nut is inserted into the right-handed screw portion and a left-handed screw nut is inserted into the left-handed screw portion. A fastening method characterized in that the first member and the second member are fastened without rotating these nuts by rotating the stud bolt after fitting. The fastening method according to claim 1, wherein the stud bolts are rotated while restricting the rotation of these nuts. The fastening method according to claim 1 or 2, wherein the stud bolt is rotated by using a drive unit formed on its head. 1. Or the fastening method according to 2.

Images