JP2860949B2 - Fastener - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fastener which is inserted into a through hole formed in a plurality of members to fix the plurality of members.

[0002]

2. Description of the Related Art One of such fasteners is a bolt and a nut. However, when a normal bolt and a nut are used to fasten another member to an outer peripheral surface of an intermediate portion of a long tubular member, for example, a bolt and a nut are used. One of the bolt and the nut must be inserted to a predetermined position to perform the fastening operation. This is a very difficult task and can be almost impossible.

[0003] As one of the fasteners which can easily perform such fastening, for example, Japanese Patent Publication No. 48-2 / 1972
There is one described in No. 4975. The fastener comprises a female screw member and a male screw member, and the female screw member is disposed at a circumferential end of the cylindrical portion having a female screw formed on an inner peripheral surface thereof and at one end of the cylindrical portion. And a plurality of engaging pieces. Each engaging piece is inclined so as to move away from the axis of the cylindrical portion toward the distal end, and is elastically deformed so that the distal end can move in a direction approaching or separating from the axis of the cylindrical portion. It is possible. On the other hand, the male screw member has a head portion and a leg portion, and the leg portion is screwed into the cylindrical portion of the female screw member from an engagement one end.

When two members are fastened by the above-mentioned fastener, a male screw member is screwed to a female screw member,
The female screw member is sequentially inserted into the through holes of the two members. At this time, the diameter of the imaginary circle formed by the outer surface of the distal end portion of each engaging piece is larger than the inner diameter of each through-hole, but since each engaging piece is elastically deformed so as to be tapered, the female screw member is inserted into each through-hole. It is possible. When the female screw member passes through the two through holes, each engagement piece returns to its original state by its own elasticity. Thereafter, when the male screw member is rotated in one direction with respect to the female screw member, the head and the engagement piece move closer to each other, and the two members are clamped and fixed.

[0005]

In the above-mentioned conventional fastener, at least one of the through holes of the two members to be fastened has a diameter of an imaginary circle formed by the tip of each of the engaging pieces. It is larger than the inner diameter of the through hole of the member that abuts.
For this reason, once the female screw member has passed through each through hole, there has been a problem that the fastener cannot be removed from the through hole.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and has a cylindrical portion having an internal thread formed on an inner peripheral surface thereof and a circumferentially spaced one end portion of the cylindrical portion. A plurality of engagement members, each of which has a distal end located radially outward of the cylindrical portion from the base end, and is elastically deformable such that the distal end can move in a direction approaching or moving away from the axis of the cylindrical portion. A female screw member having a mating piece; a leg screwed to the female screw portion of the cylindrical portion; and a head formed at an end of the leg portion protruding outside from one end of the female screw member on one side. In a fastener provided with a male screw member, a holding cylinder is provided on the outer periphery of the female screw member so as to internally house the female screw member so as to be movable in the axial direction. At least the tip of the piece forms a window hole that can protrude to the outside, A flange portion protruding radially outward is formed at an end located between the piece and the head, and a female screw member is provided on at least one of an outer surface of the engagement piece and an inner peripheral surface of the holding cylinder. An inclined surface is formed that elastically deforms the engaging piece so that the tip of the engaging piece moves in a direction approaching the axis of the cylindrical part by contacting the other side when moving from the engaging side to the cylindrical part side. It is characterized by doing. In this case, for the reason described later, it is desirable to form a reinforcing projection that abuts against the inner peripheral surface of the holding cylinder on the side of the engagement piece. In addition, it is desirable that the edge of the window, which is located on the side of the cylinder, be set so as to abut against the intermediate portion of the engagement piece during fastening. Further, it is desirable to provide a locking mechanism between the male screw member and the holding cylinder for preventing the male screw member from moving from the cylindrical portion side to the engagement side beyond the predetermined position with respect to the holding cylinder.

[0007]

In a state where the female screw member, the male screw member and the holding cylinder are assembled, they are inserted into the respective through holes of the plurality of members to be fastened from the distal end side of the leg. When the engagement piece passes through each through hole, the male screw member is rotated, and the two members are clamped and fixed by the head and the engagement piece. At this time, the flange portion of the holding cylinder is clamped and fixed between the head and the member adjacent thereto. When taking out the fastener from the through hole, first, the male screw member is turned in the other direction and loosened. Next, the female screw member is moved from one side of the engagement toward the cylinder. This movement can be performed by pushing the male screw member in the same direction or by rotating the male screw member in the other direction. When the female screw member is moved in the same direction, each engaging piece is made to have an inclined surface such that the distal end of each engaging piece moves toward the axis of the cylindrical portion. When the diameter of the imaginary circle formed by the tips of the engagement pieces becomes smaller than the inner diameter of the through hole, the fastener is taken out from the through hole toward the head. When the reinforcing protrusion is formed on the engaging piece, the reinforcing protrusion abuts against the inner peripheral surface of the holding cylinder at the time of fastening and fixing, thereby reinforcing the engaging piece, and the engaging piece elastically exceeds a predetermined amount toward the outside. Prevents deformation. When the edge located on the cylindrical portion side of the window hole abuts on the intermediate portion of the engagement piece at the time of fastening, the engagement piece is reinforced by the edge. If a locking mechanism is provided between the male screw member and the holding cylinder, the female screw member can be moved from one engagement side to the cylinder part side by rotating the male screw member in the other direction.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows that two plate members P ₁ and P ₂ are fixed by the fastener A according to the present invention.
Then fasteners A plate material P _1, through the P ₂ holes P ₁ a, and shows the procedure for removal from P ₂ a, FIG. 2 is an exploded perspective view of the fastener A. As shown in these drawings, the fastener A includes a female screw member 1, a male screw member 2, and a holding cylinder 3.

The female screw member 1 has a cylindrical portion 11 as shown in FIGS. A female screw portion 12 is formed on the inner peripheral surface of the cylindrical portion 11. Also, the cylindrical portion 11
A plurality (four in this embodiment) of engagement pieces 13 extending forward from the one end face are arranged at equal intervals in the circumferential direction. The engagement piece 13 has a thin portion 14 on the proximal end side and a thick portion 15 on the distal end side, and is slightly inclined so as to be away from the axis L of the cylindrical portion 11 toward the distal end side. I have. As a result, as shown in FIG. 1, an imaginary circle formed by the tip of the inner surface of each engagement piece 13 forms a through hole P _{1 of two} plate materials P ₁ and P ₂ to be fastened.
a, substantially equal to the inner diameter of P ₂ a, a virtual circle formed by the tip of the outer surface of the engaging piece, the through hole P ₁ a, has a larger diameter than P ₂ a. In addition, the engagement piece 13 includes a thin portion 14,
In particular, when the base end portion is elastically deformed, the front end portion can approach and separate from the axis L. The distal end surface of the engagement piece 13 (thick portion 15) is the axis L
And a plane orthogonal to.

An inclined surface 16 is formed on the outer surface of the engagement piece 13 between the thin portion 14 and the thick portion 15. The inclined surface 16 abuts against an inner surface of the holding cylinder 3 to be described later, thereby elastically deforming the engaging piece 13, particularly the base end of the thin portion 14, such that the distal end of the engaging piece 13 approaches the axis L. It is inclined so as to become farther away from the axis L from the base end side toward the front end side.

In this embodiment, since the engaging piece 13 is inclined so as to be separated from the axis L from the base end to the distal end, the inclined surface 16 is not formed, for example, as shown in FIG. As shown by an imaginary line in (C), the outer surface of the thick portion 15 and the outer surface of the thin portion 14 are the same surface,
The outer surface itself of the engagement piece 13 may be an inclined surface. It goes without saying that even in such a case, it belongs to the scope of the invention. Further, the inclined surface 16 may be curvedly inclined without being linearly inclined. In other words, the cross-sectional shape may be curved instead of straight.

Reinforcement protrusions 17 are formed on both sides of a portion extending from the base portion to the substantially half portion of the thick portion 15 and the inclined surface 16. The outer surface 17a of the reinforcing projection 17 is formed in an arc surface extending parallel to the axis L of the cylindrical portion 14, and the outer surface 17a abuts against the inner peripheral surface of the holding cylinder 3 to reinforce the engaging piece 13. ,
The engagement piece 13, especially the thick portion 15 thereof, is prevented from moving beyond a predetermined amount in a direction away from the axis L.

The male screw member 2 has a head portion 21 and a leg portion 22, as shown in FIGS.
The head 21 has a circular shape, and as shown in FIG.
The outer peripheral surface is provided with a knurled knurl.
Thus, the head 21 can be rotated by hand. Further, a cross-shaped groove 21a is formed on one end surface of the head 21 so that the head 21 can be rotated by a Phillips screwdriver (not shown). Of course, it may be formed in a hexagonal cross section so that the head 21 can be rotated by a spanner (not shown).

The leg 22 extends from the center of the other end surface of the head 21 and has a male screw 23
Are formed. The male screw portion 23 is provided on the cylindrical portion 11.
Is screwed into the female screw portion 12 from the engagement piece 13 side.
A shaft portion 24 is formed at the center of the distal end surface of the leg portion 22, and a flange portion 25 is formed at the distal end portion of the shaft portion 24. The outer peripheral surface of the flange portion 25 is formed as a tapered surface having a smaller diameter from the base end toward the distal end.

The holding cylinder 3 accommodates the female screw member 1 so as to be movable in a direction in which the axis L extends.
As shown in FIG. 2 and FIG. 6, it has a cylindrical shape and has a large diameter portion 31 at one end and a small diameter portion 32 at the other end. The outer diameter of the large diameter portion 31, the through hole P ₁ a, has become equal to or less than the inner diameter of the P ₂ a. On the other hand, the inner diameter of the small diameter portion 32 is formed to be substantially the same as or slightly larger than the outer diameter of the cylindrical portion 11 of the female screw member 1. A small diameter portion 3 is provided between the large diameter portion 31 and the small diameter portion 32.
Tapered portion 33 that expands in diameter from the second side toward the large diameter portion 31
Are formed. The inclination angle of the inner peripheral surface of the tapered portion 33 is substantially equal to the inclination angle of the engagement piece 13.

A plurality of (the same number as the engagement pieces 13) window holes 34 extending in the axial direction are formed in the peripheral wall portion of the large diameter portion 31 at equal intervals in the circumferential direction. The width of the window hole 34 is set to be equal to or greater than the width of the engagement piece 13, and the thick portion 15 of the engagement piece 13 can be protruded from the window hole 34. However, as shown in FIG. 4, the inner diameter of the large-diameter portion 32 is substantially equal to the diameter of an imaginary circle formed by the outer surface 17 a of each reinforcing projection 17. The contact with the peripheral surface prevents the thick portion 15 from protruding from the window hole 34 any more. In this case, as shown in FIG.
2, the diameter of the virtual circle formed by the tip of the inner surface of each engagement piece 13 is set to be substantially the same as the outer diameter of the large-diameter portion 32. The entire distal end face of the meat portion 15 projects outside from the window hole 34.

At the end of the large diameter portion 32, a flange portion 35 is formed. The flange portion 35 is holding cylinder 3 through hole P ₁ a, is intended to prevent the passing through the P ₂ a, the through hole P ₁ a, is larger than P ₂ a. In this embodiment, it is formed in such a size that at least a part thereof protrudes radially outward of the head 21. More specifically, the flange 35 is formed in a substantially square shape, and the length of each side is substantially equal to the outer diameter of the head 21. Therefore, each corner of the flange 35 projects from the head 21.

On the other hand, a bottom portion 36 is formed at the end of the small diameter portion 32. In the center of the bottom 36, the insertion hole 3 is provided.
7 are formed. The shaft portion 24 of the male screw member 2 is movably and rotatably inserted into the insertion hole 37. However, the inside diameter of the insertion hole 37 is set to be smaller than the outside diameter of the leg 22 (male thread part 23) and the outside diameter of the large-diameter end of the flange 25. Therefore, the male screw member 2 is
It is movable within the range of the flange 25 from the end face of the male screw part 23 with respect to the holding cylinder 3, and is prevented from falling off by the two parts 23, 25. As is clear from this, the collar 2
The locking mechanism for preventing the male screw member 2 from moving from the side of the leg 22 to the side of the head 21 with respect to the holding cylinder 3 is constituted by the bottom 5 and the bottom 36. Of course, the locking mechanism is not limited to such a structure, and another structure may be adopted.

A notch 38 is formed in the bottom portion 36 and extends radially from the insertion hole 37.
The inner diameter of 7 is larger than the outer diameter of the small-diameter end of the flange 25. Therefore, when the flange 25 is pushed into the insertion hole 37 from the small-diameter side end, the diameter of the insertion hole 27 is increased, whereby the flange 25 can be inserted through the insertion hole 37. .

Next, a description will be given of a case where the two plate members P ₁ and P ₂ are tightened and fixed by the fastener A having the above structure. The female screw member 1, the male screw member 2 and the holding cylinder 3 are shown in FIG.
It is assembled in advance as shown in FIG. That is, as shown in FIG. 2, the leg portion 22 of the male screw member 2 is inserted into the female screw member 1 from the engagement piece 13 side, and the male screw portion 23 is screwed to the female screw portion 12. In this case, screwing is performed until the distance between the head 21 and the distal end surface of the engagement piece 23 becomes larger than the sum of the thicknesses of the plate materials P ₁ and P ₂ and the flange portion 35. . Then, the female screw member 1 and the male screw member 2 are inserted into the holding cylinder 3 from the flange portion 35 side. When the flange portion 25 passes through the insertion hole 37 and the shaft portion 24 is inserted into the insertion hole 37, the cylindrical portion 1
1 fits into the small-diameter portion 32 of the holding cylinder 3, and the thick portion 15 of the engagement piece 13 enters the window hole 34, and almost the entire distal end surface of the thick portion 15 projects outside from the window hole 34. Become like

After assembling as described above, the fastener A is moved from the bottom 36 side of the holding cylinder 3 to the through holes P ₁ a, P ₁ a of the plate materials P ₁ , P ₂ .
P ₂ a, and as shown in FIG.
From the through holes P ₁ a and P ₂ a. Next, the head 21
As a result, the male screw member 2 is rotated in one direction with respect to the holding member 3. In this case, the flange 35 of the holding cylinder 3, in particular, a portion protruding radially outward from the head 21 is pressed down, or the head 21 is pulled from the leg 22 side to the head 21 side to engage the engagement piece. by pressing the front end face 13 to the plate P _2, the holding cylinder 3 can be prevented from rotating together with the externally threaded member 2.

When the male screw member 2 is rotated in one direction, the engaging piece 13 and the head 21 move closer to each other, and the plate members P ₁ and P ₂ and the flange portion 35 are clamped and fixed by them (FIG. 1 (B)). )reference). At this time, since the engagement piece 13 is inclined and its distal end projects outside the base end, the engagement piece 1
A rotational moment acting on the end 3 moves the tip outward. The reinforcing projection 17 abuts against the inner peripheral surface of the holding cylinder 3 to support the rotational moment.
Therefore, the thick portion 15 does not protrude outward by more than a predetermined amount due to the rotational moment, or is not deformed by bending.

When taking out the fastener A from the through holes P ₁ a and P ₂ a, the male screw member 2 is first rotated in the other direction with respect to the holding cylinder 3, and the head 21 and the engagement piece 13 are Are moved away from each other to release the fixing of the members P ₁ and P ₂ . Next, by moving the female screw member 1 with respect to the holding cylinder 3 from the engagement piece 13 side to the cylinder portion 11 side,
The engagement piece 13 is housed in the holding cylinder 3. There are the following two methods for moving the female screw member 1 to accommodate the engagement pieces 13.

One method is to release the fixing as described above and then push the male screw member 2 in the direction of the arrow in FIG. That is, after the fixing is released, the male screw member 2 is further rotated in the other direction with respect to the holding cylinder 3 so that the female screw member 1 has the inclined surface 16 formed on the inner periphery of the tapered portion 33 as shown in FIG. Move until it touches the surface. afterwards,
As shown in FIG. 1C, the head 2 is pressed in the direction of the arrow to move the male screw member 2 and the female screw member in the same direction.
At this time, the holding cylinder 3 is stopped is prevented movement in the same direction by the plate P _1. Therefore, the female screw member 1
Move in the same direction, the inclined surface 16 comes into contact with the large-diameter side edge of the inner peripheral surface of the tapered portion 33 with the movement, and the cylindrical portion 1
It is pressed in a direction approaching one axis L. Due to the pressing force acting on the inclined surface 16, the engagement piece 13, particularly the thin portion 1
4 is elastically deformed, and the distal end of the engagement piece 13 is the axis L.
Move to approach. When the entire engagement piece 13 is located inside the outer peripheral surface of the holding cylinder 3, the male screw member 2 is pulled by holding the head 21 in the direction opposite to the direction of the arrow in FIG. At this time, the female screw member 1 is screwed and integrated with the male screw member 2, and the holding cylinder 3 is formed by a frictional force acting between the engagement piece 13 and the tapered surface 33.
Since 3 is integrated with the female screw member 1, in their entirety through hole P ₁ a, is taken out from the P ₂ a.

In another method, after the fixing is released as described above, the flange 25 of the male screw member 2 is connected to the bottom 36 of the holding cylinder 3.
The male screw member 2 is further rotated with respect to the holding cylinder 3 to another method in a state where the male screw member 2 is in contact with the holding cylinder 3. When the male screw member 2 is rotated to another method, the female screw member 1 moves in the direction of the arrow in FIG. 1 (C), and is in the state shown in FIG. 1 (A). Thereafter, when the male screw member 2 is further rotated in the other direction, the female screw member 1 further moves in the direction of the arrow, and the inclined surface 16 is pushed by the large-diameter edge of the inner peripheral surface of the tapered portion 33 to engage. The tip of the piece 13 moves so as to approach the axis L.
At this time, the male screw member 2 is pushed from the leg 22 side toward the head 21 side by the force acting between the inclined surface 16 and the tapered portion 33, but the flange 25 abuts against the bottom 36 of the holding cylinder 3. So they do not move in the same direction.
Then, similarly to the above-described method, when the entire engagement piece 13 is positioned inside the outer peripheral surface of the holding cylinder 3, the fastener A
Whole through-hole P ₁ a, are those taken from P ₂ a.

Next, another embodiment of the present invention shown in FIG. 7 will be described. This fastener B is suitable when a large tightening force is not required, and does not require a large tightening force. Therefore, the reinforcing protrusion 17 in the above embodiment is not formed. Alternatively, in a state in which the distal end portion of the thin portion 14 is brought into contact with the tapered portion 33, spacing plate P ₁ between the front end surface and the head 21 of the engaging piece 13, P ₂ and the flange portion 35
The dimensions of each part are set so as to be slightly larger than the sum of the respective thicknesses.

In such a fastener B, the male screw member 2 is rotated in one direction from the state shown in FIG.
There move the female screw member 1 until contacting the member P _2, the engaging piece 13 is separated from the tapered portion 33. Therefore, when the female screw member 1 is further moved in the same direction in order to fix the plate members P ₁ and P ₂ , the engagement piece 13, particularly its thin portion 14, is moved so that the tip end of the engagement piece 13 is separated from the axis L. Is elastically deformed. Then, the thin portion 14 comes into contact with the tapered portion 33. At this time, the contact portion of the thin portion 14 with the tapered portion 33 is in the vicinity of the distal end portion because the female screw member 1 moves a little. Therefore, when the tightening force is small, the engagement piece 13 can be sufficiently reinforced by the tapered portion 33.

In the case of the fastener B, the head 21 cannot be pushed down in the direction of the arrow as is apparent from the state shown in the figure. Therefore, the fastener B is inserted into the through hole P ₁
a, P ₂ a, the male screw member 2 is rotated to move the female screw member 1 in the same direction.
Therefore, in the fastener B, it is essential that the male screw member 2 is prevented from moving in the direction opposite to the arrow direction with respect to the holding cylinder 3 by the flange 25.

The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit of the present invention. For example, in the above embodiment,
Although two plate members P ₁ and P ₂ are fixed, it is also possible to fix three or more members at the same time. Although the engaging piece 13 is inclined with respect to the axis L, the engaging piece 13 is formed parallel to the axis L, and a protruding portion that protrudes outward is formed at the front end thereof. The portion may be positioned so as to be separated from the axis L of the cylindrical portion 11 from the base end. Further, the female screw member 1 has a slope 1
Although 6 is formed, an inclined surface may be formed on the inner peripheral surface of the holding cylinder 3. In the above embodiment, the inner peripheral surface of the tapered portion 33 can be an inclined surface. In this case, for example, a protrusion that contacts the inner peripheral surface of the tapered portion 33 is formed on the outer surface of the engagement piece 13.

[0030]

As described above, according to the fastener of the present invention, when one of the female screw member and the holding cylinder is moved from one engagement side to the cylindrical part side, the other is connected to the other side. By forming an inclined surface for moving the distal end of the engagement piece toward the axis of the cylinder by abutting, the engagement piece can be stored in the holding cylinder, and therefore, after fixing a plurality of members, Even if there is, the effect that the fastener can be taken out from the through hole of each member can be obtained. When the reinforcing projection is formed on the engaging piece, the reinforcing projection abuts against the inner peripheral surface of the holding cylinder, thereby preventing the engaging piece from elastically deforming outward beyond a predetermined amount. Therefore,
A plurality of members to be fixed can be fixed with a large tightening force. Also, the edge located on the cylinder side of the window hole,
When the position is set so as to abut on the intermediate portion of the engagement piece at the time of fastening, the engagement piece can be reinforced by the edge. Furthermore, when the edge portion located on the cylindrical portion side of the window hole is set so as to abut against the intermediate portion of the engagement piece at the time of fastening, by rotating the male screw member in the other direction,
The female screw member can be moved from one side of the engagement toward the cylinder.

[Brief description of the drawings]

FIG. 1 is a view for explaining an operation of a fastener A according to an embodiment of the present invention, and FIG. 1A shows a state in which the fastener A is inserted into through holes of two members; FIG. 1B shows a state in which the two members are fixed by the fastener A, and FIG.
(C) shows a state before the fastener A is taken out from the through hole.

FIG. 2 is an exploded perspective view of a fastener A.

FIG. 3 is a perspective view of a fastener A.

FIG. 4 is an enlarged sectional view taken along the line DD of FIG. 1 (A).

5 (A) is a plan view, FIG. 5 (B) is a front view thereof, FIG. 5 (C) is a front sectional view thereof, and FIG. 5 (D) is a view showing a female screw member. It is the perspective view.

6 (A) is a plan view, FIG. 6 (B) is a front view thereof, and FIG. 6 (C) is a front sectional view thereof.

FIG. 7 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List A fastener B fastener L axis 1 internal thread member 2 external thread member 3 holding cylinder 11 cylinder section 12 internal thread section 13 engaging piece 16 inclined surface 21 head 22 leg 25 flange 34 window hole 35 flange 35 bottom

Claims (4)

(57) [Claims] A cylindrical portion having an internal thread formed on an inner peripheral surface thereof; and a cylindrical portion formed at one end of the cylindrical portion so as to be spaced apart from each other in a circumferential direction, and a distal end portion is located radially outward of the cylindrical portion from a base end portion. A female screw member having a plurality of engaging pieces elastically deformable so that the tip can move in a direction approaching and separating from the axis of the cylindrical portion, and a leg screwed to the female screw portion of the cylindrical portion And a male screw member having a head formed at an end of a leg portion protruding outside from an engagement end on one side of the female screw member. A holding cylinder for accommodating the member movably in the axial direction is provided inside the holding cylinder, and a window hole is formed in a peripheral wall of the holding cylinder so that at least a distal end of the engaging piece can protrude to the outside. At the end located between the piece and the head, a flange projecting radially outward At least one of the outer surface of the engagement piece and the inner peripheral surface of the holding cylinder is formed on the outer surface of the engagement piece when the female screw member moves from the one engagement side to the cylinder portion side, and thereby contacts the other side. A fastener having an inclined surface for elastically deforming an engagement piece so that a tip portion moves in a direction approaching an axis of a cylindrical portion. 2. The fastener according to claim 1, wherein a reinforcing projection is formed on a side portion of the engagement piece to abut against an inner peripheral surface of the holding cylinder. 3. The fastener according to claim 1, wherein an edge portion of the window hole located on the cylindrical portion side is set so as to abut against an intermediate portion of the engagement piece at the time of fastening. . 4. A locking mechanism is provided between the male screw member and the holding cylinder to prevent the male screw member from moving beyond the predetermined position with respect to the holding cylinder from the cylinder portion side to the engagement side. The fastener according to claim 1, wherein: