JPH0925922A - Bolt and method of tightening by using this bolt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable production cost to be decreased by reducing the amount of material to be used in addition to easiness of manufacture due to small man hour required for manufacture. SOLUTION: On the tip end of the screw shaft part 4 of a bolt main body 1 capable of being welded to a base, a bolt in which an expanded head part 2 for engagingly locking a chuck is provided aside via a breaking narrow neck part 3, and a sleeve capable of making plastic deformation through a member to be clamped is loosely fitted to the screw shaft part 4 erected on the base by welding the bolt on the base and this sleeve is brought in press contact with the member to be clamped while being caulked from the side surface by means of a caulking tool so that the sleeve may be formed in a nut in which a female screw part is formed and simultaneously the member to be clamped is tightened to the base. In addition, the engagingly locking claw of the chuck stored inside of the caulking tool is engagingly locked to the expanded head part 2 of the bolt main body 1 and tracted so that the expanded head part 2 may be broken and removed from the narrow neck part 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diameter reduction method in which a sleeve is loosely fitted to a threaded shaft portion of a base through a member to be fastened when the base is erected, and the sleeve is crimped to the member to be fastened by a caulking tool. The present invention relates to a bolt in which the inner surface of the sleeve is formed into a female screw corresponding to the male screw of the screw shaft portion, and a fastening method using the bolt.

[0002]

2. Description of the Related Art A sleeve which is erected on a base and is loosely fitted to a screw shaft portion through a member to be fastened is pressed against the member to be fastened by a caulking tool to reduce the diameter of the inner surface of the sleeve. A bolt designed to be formed into an internal thread corresponding to the external thread of the portion is conventionally known. However, this type of conventional bolt has a bolt main body 21 as shown in FIGS.
However, a small-diameter screw portion 24 having a diameter smaller than that of the screw shaft portion 22 is connected to the tip of the screw shaft portion 22 following the bolt head 20 through a thin neck portion 25 for breaking. The stud bolt is welded to the base B with the bolt head 20 and the screw shaft portion 22 is erected on the base. A possible sleeve 23 is loosely fitted, and then the caulking tool 30 presses the sleeve 23 against the member W to be tightened and reduces the diameter to form an internal thread formed on the inner surface so as to correspond to the screw shaft portion 22. A nut integrally screwed to the screw shaft portion 22 is used to tighten the member W to be fastened to the base B, and a female screw type chuck 31 screwed to the thin screw portion 24 is used to tighten the thin screw portion. By pulling 24, So that breaking remove screw portion 24.

However, in the bolt used in such a tightening method, as described above, the small diameter screw portion 24 for breaking formed in the bolt main body 21 has a smaller diameter than the screw shaft portion 22 and also has a different lead. When the thread is rolled on the bolt main body 21, the screw shaft portion 22 and the small-diameter thread portion 24 cannot be rolled at the same time, and the thread rolling needs to be repeated a plurality of times, resulting in poor productivity. Moreover, the narrow neck portion 2 is pulled by pulling the small-diameter screw portion 24 that is screwed with the screw portion 31a of the chuck 31.
In order to rupture No. 5, a considerable screw length is required to withstand the force required for rupture, the material required for production increases, the production cost rises, and the portion to be discarded becomes enormous. was there.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above problems and uses a bolt that can be manufactured with a small number of man-hours, is easy to manufacture, and can reduce the manufacturing cost by reducing the amount of materials used. To provide a fastening method.

[0005]

SUMMARY OF THE INVENTION The present invention, which has solved the above-mentioned problems, is an expansion for chuck locking through a thin neck portion for breaking at the tip of a screw shaft portion mainly composed of a bolt that can be welded to a base. The head is connected in series, and an enlarged head for locking the chuck is installed in series through a narrow neck part for breaking at the tip of the screw shaft part that is mainly a bolt that can be welded to the base. A bolt that has been welded is welded to a base, and a plastically deformable sleeve is loosely fitted to a screw shaft portion that is erected on the base through a tightening member, and this sleeve is caulked from a side surface by a caulking tool. While press-contacting the tightening member, the sleeve is molded into a nut having a female screw portion formed by a male screw portion on the inner surface, and the tightened member is tightened to the base by this nut,
A fastening method, characterized in that the locking claw of a chuck built into a caulking tool is locked to an enlarged head mainly composed of bolts and pulled to thereby break and remove the enlarged head from the narrow neck portion. Is.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the bolt of the present invention, the shape of the enlarged head formed at the tip of the bolt is preferably substantially hemispherical in consideration of handling safety. As the narrow neck formed on the bolt shaft,
The lower surface of the expansion head should be formed by connecting the expansion head through a short tapered taper shaft that does not have a screw so that the lower surface of the expansion head is formed by a flat caulking tool locking part, or by screwing. It may be formed by connecting an enlarged head portion to the tip of the shaft portion and providing an arcuate ring groove at the tip of the screw shaft portion immediately below the enlarged head portion.

[0007]

Next, the present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 shows a first embodiment of a bolt of the present invention. Reference numeral 1 is a bolt main body of the bolt of the present invention which is erected on a base, and a tip portion of the bolt main body 1 is for locking a caulking tool. The enlarged head portion 2 is formed, and the narrow neck portion 3 for breaking the enlarged head portion is formed immediately below the enlarged head portion 2 so that the tip of the screw shaft portion 4 is narrowed. The narrow neck portion 3 formed at the tip of the screw shaft portion 4 constricts the screw shaft portion 4 immediately below the enlarged head 2 so that the lower surface of the enlarged head 2 is formed into the flat chuck engaging portion 2a. Short taper shaft 4a
The narrow neck portion 3 facilitates breakage and separation of the enlarged head portion 2. Reference numeral 5 denotes a welding bolt head of the bolt main body 1. On the upper surface of the bolt head 5, welding projections 5a are provided at three places. Incidentally, 6 is a male screw portion formed on the screw shaft portion 4 of the bolt main body 1.

In the fastening method using the bolt thus constructed, first, as shown in FIG. 2, the bolt main body 1 is welded to the base B with the welding projection 5a formed on the upper surface of the bolt head 5. Then, the tightened member W is fitted into the threaded shaft portion 4 of the bolt main body 1 erected on the base B through the through hole H and received by the seat surface of the bolt head 5. Then, the sleeve 7 is loosely fitted to the bolt shaft portion 4. The sleeve 7 is made of a metal that is softer and plastically deformable than the bolt main body 1 that is loosely fitted to the screw shaft portion 4 of the bolt main body 1 and crimped to the male screw portion 6, and the sleeve 7 is composed of a main cylinder portion 7a and a hexagonal shape. The sleeve 7 is loosely fitted to the screw shaft portion 4 so that the collar portion 7b is mounted on the member W to be tightened.

Then, the caulking head 1 of the caulking tool 10
1 is fitted into the main cylinder portion 7a of the sleeve 7, and the caulking tool 10 presses the sleeve 7 against the member W to be clamped, and the main cylinder portion 7a is narrowed and crimped to reduce the diameter.
Internal thread is engraved on the inner surface of. At this time, the locking claw 12a of the chuck 12 contacts the enlarged head 2, and the caulking head 11
The tip hole 14a of the chuck holding cylinder 14 fitted inside
The taper-shaped chuck 12 fitted in the retracted part retreats against the elastic force of the spring 13, and by this retreat, the chuck 12 is expanded and the expanded head 2 enters the locking claw 12a.

Next, as shown in FIG. 3, if the chuck holding cylinder 14 of the caulking tool 10 is lifted up together with the chuck 12 while the caulking head 11 is pressed against the sleeve 7, the chucked portion 12 is enlarged by the chuck portion 12. The head 2 is pulled and, as shown in FIG. 4, the narrow neck 3 for expanding the head is broken.
As a result, the to-be-tightened member W is fixed to the bolt main body 1 by being fractured and separated. Further, the crimped sleeve 7 is formed with a female screw portion corresponding to the male screw portion 6 of the bolt main body 1, so that a rotating tool such as a wrench is engaged with the hexagonal portion formed on the outer shape of the sleeve 7. If the sleeve 7 that is made into a nut is rotated, the sleeve 7
Can be removed from the bolt body 1. Further, FIG. 5 shows a second embodiment, in which a point where a projection 5a for welding is formed on the seating surface of the bolt head 5 and the enlarged head 2 is continuously provided at the tip of the screw shaft portion 4. The first embodiment described above in that the enlarged head 2 is easily broken and separated by the narrow neck portion 3 formed by providing the circular arc groove 4b at the tip of the screw shaft portion immediately below the enlarged head 2. The description is omitted because the other configurations are the same and the other configurations are the same. In this embodiment, the hexagonal portion is formed on the main tubular portion 7a of the sleeve 7 before crimping, but the flange 7b is a stepless sleeve, and the polygonal portion is formed during crimping. Good as a thing.

[0011]

As is apparent from the above description, the bolt of the present invention is an enlarged head for chuck locking through a breaking narrow neck portion at the tip of a screw shaft portion of a bolt main body that can be welded to a base. Since the parts are arranged in series, it is possible to securely chuck to the caulking tool, and since it is not a chuck by screwing as in the past, the enlarged head can be small and the material to be discarded can be reduced. It is economical. Moreover,
Since the enlarged head is small, the material used during manufacturing can be significantly reduced as compared with the conventional one, so that the material cost can be reduced and the manufacturing can be performed at low cost. Furthermore, when rolling the male screw part mainly on the bolt, the narrow neck part and the enlarged head part can be formed by rolling at the same time. The cost can be reduced. Further, according to the fastening method using this bolt, a strong fastening state can be easily performed without screwing in addition to the effect brought by the stud bolt as described above, so that work efficiency is improved. There is an advantage that can be done. Therefore, the present invention is extremely significant in that it contributes to the development of the industry as a bolt and a fastening method using the bolt that have solved the conventional problems.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing a first embodiment of the present invention.

FIG. 2 is a partially cutaway front view showing a state before caulking according to the first embodiment of the present invention.

FIG. 3 is a partially cutaway front view showing a crimped state of the first embodiment of the present invention.

FIG. 4 is a partially cutaway front view showing completion of crimping according to the first embodiment of the present invention.

FIG. 5 is a partially cutaway front view showing a second embodiment of the present invention.

FIG. 6 is a partially cutaway front view showing a conventional bolt tightening device.

FIG. 7 is a partially cutaway front view showing a caulking state of a conventional bolt tightening device.

[Explanation of symbols]

 1 Main body of bolt 2 Enlarged head 2a Chuck locking part 3 Neck neck part 4 Screw shaft part 4a Tapered taper shaft part 4b Arc ring groove

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[Procedure amendment]

[Submission date] July 27, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction contents]

[0002]

2. Description of the Related Art A sleeve which is erected on a base and is loosely fitted to a screw shaft portion through a member to be fastened is pressed against the member to be fastened by a caulking tool to reduce the diameter of the inner surface of the sleeve. A bolt designed to be formed into an internal thread corresponding to the external thread of the portion is conventionally known. However, this type of conventional bolt has a bolt main body 21 as shown in FIGS.
However, a small-diameter screw portion 24 having a diameter smaller than that of the screw shaft portion 22 is connected to the tip of the screw shaft portion 22 following the bolt head 20 through a thin neck portion 25 for breaking. Bol like
TMG, after having erected the threaded shaft portion 22 on the base and welded with a the bolt head 20 to the base B, which in the plastically deformable sleeve 23 softer than the bolt through the Hishimezuke member W Yu Then, the sleeve 23 is pressed against the member W to be tightened by the caulking tool 30 and the diameter of the sleeve 23 is reduced to form an internal thread on the inner surface corresponding to the screw shaft portion 22. The integrated nut is used to tighten the tightened member W to the base B, and
Female screw type chuck 3 screwed to the small-diameter screw portion 24.
1 by pulling the small-diameter screw portion 24
The small-diameter threaded portion 24 is removed by breaking from 5.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

[0011]

As is apparent from the above description, the bolt of the present invention is an enlarged head for chuck locking through a breaking narrow neck portion at the tip of a screw shaft portion of a bolt main body that can be welded to a base. Since the parts are arranged in series, it is possible to securely chuck to the caulking tool, and since it is not a chuck by screwing as in the past, the enlarged head can be small and the material to be discarded can be reduced. It is economical. Moreover,
Since the enlarged head is small, the material used during manufacturing can be significantly reduced as compared with the conventional one, so that the material cost can be reduced and the manufacturing can be performed at low cost. Furthermore, when rolling the male screw part mainly on the bolt, the narrow neck part and the enlarged head part can be formed by rolling at the same time. The cost can be reduced. Further, according to the fastening method using this bolt, a strong fastening state can be easily performed without screwing in addition to the effect brought about by the bolt as described above, which is an advantage that work efficiency can be improved. There is. Therefore, the present invention is extremely significant in that it contributes to the development of the industry as a bolt and a fastening method using the bolt that have solved the conventional problems.

Claims (5)

[Claims] 1. An enlarged head (2) for locking a chuck is connected to a tip of a screw shaft (4) of a bolt main body (1) that can be welded to a base through a narrow neck (3) for breaking. A bolt characterized by being installed. 2. The enlarged head (2) has a chuck engaging portion on the lower surface.
The bolt according to claim 1, which has a substantially hemispherical shape (2a). 3. The bolt according to claim 1, wherein the narrow neck portion (3) is formed by a non-threaded tapered taper shaft portion (4a) following the tip of the screw shaft portion (4). 4. The narrow neck portion (3) has a thread-free circular ring groove (4) provided at the tip of the screw shaft portion (4) immediately below the enlarged head portion (2).
The bolt according to claim 1 or 2, which is formed by b). 5. A bolt, in which an enlarged head for chuck locking is connected to the tip of a screw shaft portion mainly composed of a bolt that can be implanted in a base through a thin neck portion for breaking, is welded to the base. A sleeve that is plastically deformable is loosely fitted to the screw shaft part that is erected on the base through the member to be clamped, and this sleeve is crimped from the side while crimping the sleeve to the inner surface of the sleeve by crimping. A nut with a female thread formed by the male thread of the screw shaft is formed, and this nut tightens the member to be fastened to the base, and the locking claw of the chuck built into the caulking tool expands mainly with bolts. A fastening method, characterized in that the enlarged head is broken and removed from the narrow neck portion by being locked and pulled by.