JPH0627525B2 - Fastener - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fastener for penetrating and fastening a plurality of members to be fastened, and particularly to simplification of fastening work.

2. Description of the Related Art Bolts and nuts are often used when fastening a plurality of members to be fastened using fasteners. Since the bolt is inserted from one side into the through holes of the plurality of members to be fastened that are fitted to each other, the nut is screwed on the other side, and the head of the bolt and the nut sandwich and fasten the member to be fastened. is there. However, when connecting tubular members such as box beams of bridges and columns using square pipes for construction of houses etc., it is rare that there are sufficient working spaces on both sides of the members to be fastened. .

Therefore, the member to be fastened has a female screw hole formed in advance,
A bolt is screwed into the female screw hole, or a nut is preliminarily fixed by welding or the like to the surface of the member to be fastened opposite to the side where the bolt is inserted, and the bolt is screwed. In addition, when the member to be fastened is large and an operator can enter inside, the worker who has entered the member to be fastened may pair with the worker outside to perform the fastening work. . Furthermore, a notch may be provided in the vicinity of the portion to be fastened, and a hand may be put in the notch to perform fastening work.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, when forming a female screw hole in a member to be fastened, it takes time and labor to process, and it is necessary that the member to be fastened has a certain thickness or more in order to secure the strength of the screw. Therefore, it is unavoidable that the weight increases. If only the portion to be fastened is a separate and thick one, it is necessary to weld it to other portions, which is troublesome.

Further, it is not easy to weld the nut to the inside of the member to be fastened, which requires a lot of man-hours. Further, when two workers are paired to perform the fastening work, a large number of workers are required, which causes poor workability and limits the target members to be fastened. Furthermore, there is a problem that the number of working steps increases when the notch is provided.

On the other hand, if a blind bed that can be swaged from the inserted side is used, members such as a box beam that have a small working space can be easily fastened together. However, blind beds are popular because they have a diameter of 8 mm or less and do not require high strength.
Those requiring a diameter of 10 mm or more have not been put to practical use. Therefore, the objects that can use the blind bed are limited.

This problem is not limited to the case where a tubular member to be fastened is fastened, but is similarly a problem that occurs when there is not enough working space on both sides of the plurality of fastened members in the alignment direction.

An object of the present invention is to provide a fastener that can be operated only on one side where the fastened parts of the fastened members are joined together when fastening a plurality of fastened members. .

Means for Solving the ProblemsThe present invention, in order to solve the above problems, (a) a nut, (b) a shaft portion, provided at one end portion of the shaft portion, having a larger diameter than the shaft portion and A head having a stepped surface substantially perpendicular to the axis of the shaft, a rotation-preventing tool engaging portion provided at the other end of the shaft, and a shaft portion adjacent to the rotation-preventing tool engaging portion. And a bolt having a male screw portion screwed with the nut,
(c) A sleeve whose outer diameter is almost the same as the diameter of the head of the bolt and which is fitted onto the shaft of the bolt so as to be slidable in the axial direction,
(d) It has a tubular shape thinner than the sleeve and is slidably fitted in the shaft portion between the sleeve and the head of the bolt in the axial direction. Is almost the same as the end face and is in contact with the stepped face at a substantially right angle to the axis,
In addition, the outer diameter and the inner diameter of the sleeve-side portion are smaller than the outer diameter and the inner diameter of the head-side portion, respectively, and a buckling cylinder having a stepped portion between the both portions is included. It

The diameter of the head of the bolt is the same as or larger than the outer diameter of the sleeve and the outer diameter of the buckling cylinder on the bolt head side, but it may be small if it is small.
The phrase "the outer diameter is substantially the same as the diameter of the head of the bolt" is meant to include all of those aspects.

Action When fastening a plurality of members to be fastened by the fastener according to the present invention, the buckling cylinder and the sleeve are fitted to the bolt, and the bolt is inserted from the head side into the through hole formed in the fastened member. . By thus inserting the bolt into the through-hole from the head side, the rotation-blocking tool engaging portion and the portion of the male screw portion on the rotation-blocking tool engaging portion side are located outside one opening of the through-hole. The bolt head and part of the buckling cylinder are positioned so as to project from the other opening of the through hole. And
If the shaft of the bolt is moved in a direction in which the head of the bolt approaches the member to be fastened while preventing the sleeve from moving in the axial direction, the head of the bolt will buckle with a stepped surface that is substantially perpendicular to the axis. Since it comes into contact with the end surface that is substantially perpendicular to the axis line of, the axial compression force is applied to the sleeve and the buckling cylinder. In a state in which the nut that has been screwed in advance at a predetermined position of the male thread portion of the bolt is blocked by the rotation blocking tool that engages the rotation blocking tool engaging portion with the rotation of the bolt , Can be generated by rotating, or can be generated by a pulling tool engaged with the rotation preventing tool engaging portion.

Since the buckling cylinder is thinner than the sleeve, and the stepped portion is provided in the middle part, when a compressive force is applied to the buckling cylinder, the presence of the stepped portion causes the stepped portion of the large diameter portion to be present. A bending moment that bends that portion to the outer peripheral side is generated in the portion that is adjacent to, and a bending moment that bends that portion to the inner peripheral side is generated in the portion that is adjacent to the stepped portion of the small diameter portion. . Therefore, it should be buckled to a shape in which the diameter near the boundary between the head side portion and the stepped portion increases, or to a shape in which the diameter near the boundary portion between the sleeve side portion and the stepped portion decreases. Although at least one of them will be buckled, the buckling cylinder is prevented from buckling to the inner peripheral side because the shaft part of the bolt is arranged on the inner peripheral side of the buckling cylinder. Has been done. Therefore, the former buckling occurs, and an engaging portion that engages with the peripheral edge portion of the opening of the through hole is formed. Since the buckling strength of the portion of the buckling cylinder on the bolt head side is small, the buckling strength is not so large as the predetermined compression force, and the buckling is performed before the large compression force acts on the sleeve.

The plurality of members to be fastened are fastened by rotating the nut that has been screwed in advance to the male screw portion after forming the engaging portion or the nut that has been screwed after forming the engaging portion while the rotation of the bolt is blocked. To be done.

As described above, since the bolt of the fastener of the present invention includes the rotation-preventing tool engaging portion, the rotation-preventing tool engaged with the rotation-preventing tool engaging portion rotates the nut. It is possible to prevent rotation of the bolt due to. Further, since the rotation preventing tool engaging portion is provided at the end portion of the bolt shaft portion opposite to the head portion, the fastened member can be fastened by operating only one side of the fastened member. You can Therefore, even when the work space is small, such as when the member to be fastened is a cylindrical column, the problems such as the increase in the number of man-hours and the labor and the limitation of the fastening member do not occur as described above, and the fabrication of the fastened member is performed. And the productivity can be improved, the cost can be reduced, and the workability at the time of fastening can be improved. Further, it can be effectively used when a blind bed cannot be used because a large shaft diameter is required.

Further, since a large compressive force is prevented from acting on the sleeve, the compressive force acting on the member to be fastened is correspondingly increased, and a large fastening force is obtained.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 4 shows a rubber column 12 and a column beam 14 which are the members to be fastened, which are fastened by the fastener 10 according to the embodiment of the present invention.
And are shown. The column pillar 12 has a quadrangular cross section, and the column beam 14 is fixed to one side wall 16 of the column pillar 12. The column beam 14 also has a quadrangular cross section, and is fixed to the side wall 16 by a plurality of fasteners 10 at an end plate 18 fixed to one longitudinal end thereof. The column beams 14 are fixed to the column columns 12 at right angles.

The fastener 10 will be described with reference to FIGS. 1 to 3.
The fastener 10 includes a bolt 22, a tubular member 24, and a nut 26. The bolt 22 is a high-strength bolt that withstands a high tension sufficient to fasten the column pillar 12 and the column beam 14 in a state in which a sufficient frictional force is applied between them. The bolt 22 has a shaft portion 28 having a circular cross section, and a head portion 30 having a diameter larger than that of the shaft portion 28 is provided at one end of the shaft portion 28. At the other end of the shaft portion 28, the shaft portion 2
A tool engaging portion 34 having a diameter smaller than 8 is provided, and 12 grooves 36 extending in the axial direction are formed on the outer peripheral surface of the tool engaging portion 34. A neck portion 38 having a diameter smaller than that of the tool engaging portion is formed between the tool engaging portion 34 and the shaft portion 28. As described above, the tool engaging portion 34 has a non-circular cross section by the groove 36, and is prevented from rotating by the rotation preventing tool. Further, the neck portion 38 is formed, and the shaft portion 28 is fixed to the tool engaging portion 34. A pulling tool for pulling to the engaging portion 34 side is engaged. Further, a portion of the shaft portion 28 adjacent to the tool engaging portion 34 is a male screw portion 40.

The tubular member 24 is made of an iron-based material such as S20C, and has the same outer diameter as the diameter of the head portion 30 of the bolt 22. One end of the cylindrical member 24 is a shaft portion 28 of the bolt 22.
A sleeve 44 that is fitted in the axially slidable manner,
The outer diameter of the other end is the same as the outer diameter of the sleeve 44, and the bolt 22
Is the same as the diameter of the head 30 of the
Is thinner than the sleeve 44 and has a small buckling strength. The thickness t (see FIG. 5) of the thin portion 46 is preferably 10 to 1/20 of the inner diameter D of the thin portion 46, and the length (axial dimension) of the thin portion 46.
l is preferably 3 to 7 times the thickness t. In addition, the tubular member 2
4 is adjacent to the sleeve 44.
4 is the same as the inner diameter, but the outer diameter is a small diameter portion 48 smaller than the outer diameter of the sleeve 44. The thickness t'of the small diameter portion 48 is larger than the thickness t of the thin inner portion 46, and the length l'is preferably 3 to 7 times the thickness t '. The portion between the small diameter portion 48 and the thin portion 46 is a stepped portion 50, and the thin portion 46, the small diameter portion 48, and the stepped portion 50 are the buckling cylinder 51.
Are configured. In this embodiment, the buckling cylinder 51 and the sleeve 44 are integrally provided. The length l of the thin portion 46 has the above relationship with the thickness t, and when the thin portion 46 is buckled, as will be described later, the side wall 16 for inserting the fastener 10 is provided. 18
The size is such that an engaging portion 54 (see FIG. 2) larger than the diameter of the through-hole 52 formed in is formed. The length of the tubular member 24 is such that the thin-walled portion 46 and the stepped surface 50 are the other side of the through-hole 52 when the end surface on the opposite side of the thin-walled portion 46 is located inside the opening of the through-hole 52 by a small distance. It is sized to protrude from the opening. In addition, the bolt 22
The shaft portion 28 of the washer 58 (see FIG. 3) is fitted to the thickness of the nut 26 and the thickness of the side wall 16 and the end plate 18 when the nut is screwed, rather than the length of the tubular member 24. It is said to be longer than any of the lengths including the thickness. The boundary between the stepped portion 50 and the thin portion 46 and the small diameter portion 48 is rounded to avoid stress concentration. Also, the surface of the washer 58 opposite to the nut 26 side is a satin-finished surface,
The coefficient of friction is larger than the coefficient of friction of the surface on the nut 26 side.

Hereinafter, the fastening of the column columns 12 and the column beams 14 by the fastener 10 configured as described above will be described. First, the preliminary work tool 60 is used to form the engagement portion 54.
The preparatory work tool 60 is a dedicated tool for forming the engagement portion, and includes a pressing member 62 and a chuck 64 as shown in FIG. The pressing member 62 has a through hole 66 having a stepped surface. The small-diameter hole portion 68 has a diameter slightly larger than that of the male screw portion 40 of the bolt 22, and the chuck 64 is arranged in the large-diameter hole portion 70 so as to be expandable / compressible and movable in the axial direction. There is. The chuck 64 of the preliminary work tool 60 functions as a pulling tool. Further, a protrusion 72 having an outer diameter slightly smaller than the diameter of the through hole 52 is formed on the opening end surface of the small diameter hole portion 68 opposite to the large diameter hole portion 70 side.

First, the tubular member 24 is fitted into the shaft portion 28 of the bolt 22 in advance so that the thin portion 46 is located on the head portion 30 side, and then the tool engaging portion 34 side is passed through the small diameter hole portion 68 of the pressing member 62. And inserts it into the large-diameter hole portion 70, and causes the chuck 64 to hold the tool engaging portion 34. In this state, the head 30 of the bolt 22 is inserted into the through hole 52 formed in the side wall 16 and the end plate 18. The through hole 52 is provided in a direction parallel to the longitudinal direction of the column beam 14, and the column beam 14 side is easier to perform work, and the head portion 30 is inserted from the opening of the through hole 52 on the end plate 18 side. .

When the protrusion 72 of the pressing member 62 is fitted into the through hole 52 at the time of this insertion and the end surface of the pressing member 62 is in contact with the end surface of the end plate 18, the tip end surface of the protrusion 72 is different from the end surface of the tubular member 24. And a slight gap is left. Through hole 52
After the insertion into the end plate 18, the chuck 64 is moved in a direction away from the end plate 18, and the reaction force of the force for moving the chuck 64 is applied to the pressing member 62, and the tip surface thereof is
And the projection 72 is kept fitted in the through hole 52. The bolt 22 is moved in the direction of approaching the side wall 16 by the movement of the chuck 64.
No. 4 is prevented from moving in the axial direction in the state of being in contact with the projection 72, and only the bolt 22 is moved, so that a compressive force is applied to the tubular member 24. When the compressive force reaches a certain level, the buckling cylinder 51 begins to buckle in a form in which the diameter of the boundary portion between the thin portion 46 and the stepped portion 50 increases as shown in FIG. Engaging portion 54 larger than the diameter of the hole 52
Is formed. Since the buckling cylinder 51 is thinner than the sleeve 44 and the stepped portion 50 is provided in the middle portion thereof, when a compressive force is applied to the buckling cylinder 51, the presence of the stepped portion 50 causes the thinned portion to be formed. A bending moment is generated in a portion of the small diameter portion 48 adjacent to the stepped portion 50, and a bending moment that causes the portion to be convexly curved toward the outer peripheral side is generated. A bending moment is generated that causes it to bend. Therefore, the buckling is performed so that the diameter near the boundary between the thin portion 46 and the stepped portion 50 increases, or the diameter near the boundary between the small diameter portion 48 and the stepped portion 50 decreases. At least one of the buckles will be buckled, but since the shaft portion 28 of the bolt 22 is arranged on the inner peripheral side of the buckling cylinder 51, the small diameter portion 48 buckles to the inner peripheral side. Instead, the portion of the thin portion 46 adjacent to the stepped portion 50 will buckle outward.

Further, since the compressive force required to form the engaging portion 54 is not so large, it is possible to avoid the large compressive force from acting on the sleeve 44.

After forming the engaging portion 54 in this manner, the preliminary work tool 60
Is removed, the washer 58 is fitted to the male screw portion 40, and the nut 26 is screwed. Then, the holding portion of the tightening tool (not shown) is engaged with the tool engagement portion 34, and the nut 26
The rotation operating portion of the tightening tool is engaged with the nut 26 and the nut 26 is rotated while the rotation of the bolt 22 is blocked. The holding portion of the tightening tool functions as a rotation preventing tool.

When the nut 26 is rotated, the engaging portion 54 engages with the opening peripheral edge portion of the through hole 52, and together with the nut 26, the side wall 1 is formed.
6. When the end plate 18 is sandwiched and the rotational torque acting on the bolt 22 increases and reaches a certain value, the neck portion 38 is torsionally broken as shown in FIG. Accordingly, the rotation of the nut 26 is stopped, so that the tightening torque is constant and a constant bolt axial force is obtained. As described above, the surface of the washer 58 on the side opposite to the nut 26 has a high coefficient of friction to prevent rotation of the nut 26 when the nut 26 rotates. There is no such thing. Therefore, the nut 26 and the bolt 22 are tightened with a predetermined torque, and the neck portion 3
Side wall 1 unless tightened until torsion breaks
6. The end plate 18 is fastened with a predetermined high tension.

As described above, the side wall 16 and the end plate 18 are fixed by the fastener 10.
6 is engaged, the engaging portion 54 becomes as shown in FIG. This drawing is a photograph of the bolt 22 and the tubular member 24 when the two members to be fastened are fastened by the trial-made fastener 10 with a cross section taken along the axis and taken based on the photograph.

Thus, according to the fastener 10 of the present embodiment, the fastener 10
The column post 14 and the column beam 16 can be fastened only by the operation on the side of the column beam 14 that is the side where the column is inserted, and the tubular members with a small working space can be fastened easily and quickly.

Further, in the present embodiment, the sleeve 44 and the buckling cylinder 51.
And are integrally formed, but the outer diameter is
It is made equal to the diameter of 0. Therefore, the tubular member 2
4, the diameter of the through hole 52 can be made smaller than that in the case where the stepped portion 50 is formed by providing a portion having a larger diameter than the sleeve 44, and it is possible to prevent the strength of the member to be fastened from decreasing. it can.

In the above embodiment, the sleeve 44 and the buckling cylinder 51 are used.
However, the sleeve 90 and the buckling cylinder 92 shown in FIG. 7 may be formed separately. Both ends of the buckling cylinder 92 are thin-walled portions 94 and small-diameter portions 96 similar to the thin-walled portion 46 and the small-diameter portion 48, and a portion between the thin-walled portions 94 and the small-diameter portion 96 is a stepped portion 98. ing. The buckling tube 92 is previously attached to the bolt 22 before the fastening work.
The thin portion is fitted to the shaft portion 28 and is sandwiched between the head portion 30 and the sleeve 90 when the bolt 22 is moved with respect to the sleeve 90 and the buckling cylinder 92. Similar to 46, the thin portion 94 is buckled outward.

Further, in the embodiment shown in FIGS. 1 to 6, a preliminary work is performed before tightening the nut 26, and the engaging portion 54 is formed by moving the bolt 22 in the axial direction. However, as shown in FIG.
The buckling cylinder 51 may be buckled by the tightening force of the nut 26 to form the engaging portion 54. The structure of the fastener is the same as the fastener 10 of the above embodiment.

In this case, the bolt 22, the tubular member 24, the nut 26
Is previously assembled integrally, and the end plate 18 of the through hole 52 is
The head portion 30 of the bolt 22 is inserted into the through hole 52 from the side opening. Then, the tool engagement portion 34 is engaged with the holding portion of the tightening work tool, the rotation operation portion is engaged with the nut 26, and the nut 26 is rotated while the rotation of the bolt 22 is blocked. By rotating the nut 26, the bolt 22 is screwed in a direction in which the head portion 30 approaches the side wall 16 while applying an axial compressive force to the tubular member 24, and the compressive force applied to the tubular member 24 is applied. When the size reaches a certain size, the buckling cylinder 51 buckles to form the engaging portion 54. After that, the nut 26 is further rotated, so that the neck portion 38 is torsionally broken when the rotational torque reaches a constant value. In order to prevent the tubular member 24 from rotating together with the nut 26 during this tightening, the bolt 2
It is desirable to prevent slippage between the two heads 30 and the tubular member 24 by providing a large number of ridges extending in the radial direction on at least one of the surfaces contacting each other.

Before inserting the bolt head 30, the bolt 22, the tubular member 2
4, by assembling the nut 26 integrally,
They can be treated as an integral part of the member to be fastened, the fastening work can be easily performed, and the fastening work can be automated. Moreover, when the head portion 30 of the bolt 22 is inserted into the through hole 52, the nut 26 is fixed by the end plate 18.
Since the insertion depth of the bolt 22 is determined by abutting against, there is no fear that the bolt 22 is inserted too much and falls from the through hole, and workability is improved also in this respect.

The tubular member 24 and the buckling tube 92 may be made of a non-ferrous material such as an aluminum alloy in addition to the iron-based material.

Further, when the fastening of the fastened member does not require so high tension, the bolts constituting the fastener are the bolts 2 described above.
It is not necessary to generate a high tension as in No. 2, as long as the member to be fastened can be held by the engaging portion formed by buckling of the sleeve and the nut.

In addition, although not exemplified, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a front view showing a state in which a fastener according to an embodiment of the present invention is inserted into a through hole of a member to be fastened and a preliminary work tool is attached. FIG. 2 is a front view (partial cross section) showing a state in which the buckling cylinder is buckled by the action of the work tool. FIG. 3 is a front view (partial cross section) showing a state in which a member to be fastened is fastened by the fastener. FIG. 4 is a front sectional view showing a member to be fastened which is fastened by the above fastener. FIG. 5 is a front cross-sectional view showing a side of the tubular member of the fastener, on which the thin portion is provided. FIG. 6 is a front cross-sectional view showing the engaging portion formed at the time of fastening with the above fastener and the periphery thereof. FIG. 7 is a front sectional view showing a main part of a fastener which is another embodiment of the present invention. FIG. 8 is a front view (partial cross section) showing a state in which a fastener according to another embodiment of the present invention is inserted into a through hole of a member to be fastened. 10: Fastener, 12: Column pillar 14: Column beam, 16: Side wall 18: End plate, 22: Bolt 24: Cylindrical member, 26: Nut 28: Shaft part, 30: Head part 34: Tool engagement part, 40: Male screw portion 44: Sleeve, 46: Thin portion 48: Small diameter portion, 50: Stepped portion 51: Buckling cylinder, 54: Engaging portion 60: Preliminary work tool, 90: Sleeve 92: Buckling tube, 94: Thin part 96: Small diameter part, 98: Stepped part

Claims (2)

[Claims] 1. A fastener for penetrating and fastening a plurality of members to be fastened, comprising a nut, a shaft portion, and one end portion of the shaft portion, the diameter being larger than the shaft portion, and the axis line of the shaft portion. A head having a stepped surface substantially at right angles to the shaft, a rotation-preventing tool engaging portion provided at the other end of the shaft portion, and provided on the shaft portion adjacent to the rotation-preventing tool engaging portion. ,
A bolt having a male thread portion screwed into the nut, a sleeve having an outer diameter substantially the same as the diameter of the head portion of the bolt, and a sleeve fitted to the shaft portion of the bolt slidably in the axial direction, The sleeve has a tubular shape thinner than that of the sleeve, is axially slidably fitted to the shaft portion between the sleeve and the head portion of the bolt, and the outer diameter of the portion on the head side is almost the same as that of the head portion. It is the same and the end face abuts the stepped face at a right angle to the axis,
And a buckling cylinder in which the outer diameter and inner diameter of the sleeve-side portion are smaller than the outer diameter and inner diameter of the head-side portion, and a stepped portion is provided between the both portions. Fasteners to do. 2. The fastener according to claim 1, wherein the rotation preventing tool engaging portion has a shape capable of engaging with a pulling tool that pulls the shaft portion toward the other end portion. .