JPH11325021A - Nut and bolt/nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make fastening torque constant substantially and prevent loosening or removal by mischief. SOLUTION: This device has a nut body 7, a tool engaging part 9, and a breakage part 8 therebetween. The nut body 7 has an engaging part 11 with which an exclusive fastening tool can engage as well as no engaging part with which a generally used fastening tool can engage. The tool engaging part 9 has an engaging part with which the general fastening tool can engage. The breakage part 8 is adapted to break when fastening torque acting on the tool engaging part 9 exceeds a specified value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nut and a bolt / nut.

[0002]

2. Description of the Related Art Fastening mechanisms using bolts and nuts are well known without particular examples. The well-known fastening mechanism using the above-mentioned bolt and nut has an advantage that it can be fastened with a general-purpose fastening tool such as a spanner, a wrench, a screwdriver, or the like, but it is difficult to tighten with a fixed tightening torque. And / or the nut itself may be damaged. Further, if the tightening torque is reduced to avoid damage to these members, the tightening may be loosened over time.

Further, since a general-purpose tightening tool can be used, it is difficult to prevent loosening and removal of the nut due to mischief. Particularly, if the tightening of the nut on a transmission tower or a guardrail is loosened or removed. May cause unexpected accidents.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a nut and a bolt / nut which can make the tightening torque substantially constant and prevent loosening or removal of the tightening due to mischief or the like. Is to do.

[0005]

In order to solve the above-mentioned problems, a nut according to the present invention has a female screw which is screwed to a male screw of a bolt, and has no engaging portion on its outer surface with which a general-purpose tightening tool can be engaged. A nut formed integrally with a main body; a tool hook having an engaging portion into which the male screw can be loosely inserted and a general-purpose tightening tool can be engaged; and a broken portion between these members; It is characterized in that the breaking portion has a strength to break when the tightening torque acting on the tool hook portion exceeds a predetermined value.

In order to solve the same problem, a nut according to the present invention has a female screw to be screwed into a male screw of a bolt, and has no engaging portion on its outer surface with which a general-purpose tightening tool can be engaged. A nut body having an engaging portion that can be engaged only by the tool; a tool hook having an engaging portion into which the male screw can be loosely inserted and a general-purpose tightening tool is engaged; and a broken portion between these members; Wherein the breaking portion has a strength such that the breaking portion is broken when a tightening torque acting on the tool hook portion exceeds a predetermined value.

In order to further solve the same problem, a nut according to the present invention has a female screw which is screwed into a male screw of a bolt,
There is no engaging part on the outer surface where a general-purpose tightening tool can engage,
A nut formed integrally with a nut body and a lock nut portion having an engagement portion that can be engaged only by a dedicated fastening tool; and a break portion between these members, wherein the break portion is formed on the lock nut portion. The lock nut portion has a strength to be broken when an acting tightening torque exceeds a predetermined value, and the lock nut portion functions as a double nut for preventing loosening by breaking of a broken portion.

In order to solve the same problem, a bolt / nut according to the present invention is characterized by comprising a bolt having no engaging portion with which a general-purpose tightening tool can engage;

[0009]

The function and effect of the invention are as follows.
A female screw formed on the nut body is screwed onto a male screw of a bolt having no engaging portion with which the general-purpose tightening tool can be engaged with the head, and the general-purpose tightening tool is engaged with the engaging portion of the tool hook portion. By rotating, appropriate members between the bolt and the nut can be tightened. In this case, the nut can be fastened to the bolt by a general-purpose fastening tool, so that the nut can be easily tightened.

When the tightening torque exceeds a predetermined value, the broken portion breaks, so that the nut can be tightened with a substantially constant torque suitable for fastening, and excessive tightening and shortage of tightening force can be eliminated. In addition, when the tool hook is separated from the nut body due to the breakage of the break, there is no engaging portion on the outer surface of the nut body with which a general-purpose tightening tool can be engaged, so that loosening and removal of the nut due to mischief can be prevented. it can.

"General purpose tightening tool" in this specification
A tool that can tighten or loosen bolts and nuts, such as a well-known spanner or wrench, means that there is no engaging portion that can be used by general-purpose tightening tools. This does not mean only a head that does not have an engaging portion with which a general-purpose fastening tool can be engaged, but a head in which an arbitrary-shaped head cannot be rotated in an insertion hole, or a bolt whose head is embedded in concrete or the like. And the bolt itself cannot be rotated.

Since the nut according to the second aspect has an engaging portion on the outer surface of the nut main body which can be engaged only by a dedicated tightening tool, the nut main body can be tightened for some reason in addition to the above-mentioned effects. When the nut is loose, the nut body can be tightened with a special tightening tool.

The nut according to the third aspect of the present invention is such that when the dedicated tightening tool is engaged with an engaging portion provided on the outer surface of the nut and can be engaged only by the dedicated tightening tool, and the tool is rotated, the head is generally used. The nut can be fastened to a bolt having no engaging portion with which the tightening tool can be engaged. If the tightening torque exceeds a predetermined value, the broken part will break,
The nut can be tightened with a substantially constant torque suitable for tightening, and excessive tightening and insufficient tightening can be eliminated.

Further, when the break portion breaks, the lock nut portion separated by the break functions as a double nut, so that the nut body can be prevented from loosening. further,
Since the engaging portions that can be engaged only by the dedicated rotary tool are provided on the outer surfaces of the nut body and the lock nut portion, when the fastening of these members is loosened for some reason, the fastening can be performed by the dedicated fastening tool.

[0015]

1 to 4 show a first embodiment of the present invention in which a gear lock bolt is used. A bolt 2 on which a nut 1 is screwed is provided with a head 4 using a general-purpose tightening tool. A male screw 6 having a shape having no engaging portion that can be fitted (a ball band in the illustrated example), and a nut 1 screwed to a tip portion of the shaft portion 5.
Are formed (see FIG. 4).

The nut 1 has a shape in which the outer peripheral surface has no engaging portion with which a general-purpose tightening tool can engage (in the illustrated example, a ball band), and is reduced in diameter by an appropriate means such as cutting. Annular breaking portion 8 and nut body 7 of the breaking portion
And a tool holder 9 on the opposite side, which are integrally formed of a suitable material such as mild steel. On the outer peripheral surface of the nut body 7, a shallow engaging groove as an example of the engaging portion 11 for engaging a dedicated tightening tool (not shown) is arranged at a circumferential interval. A plurality (three in the illustrated example) is formed in the axial direction, and a female screw 12 to which the male screw 6 of the bolt 2 is screwed is formed at the center.

The tool hook 9 shown in the drawing has a regular hexagonal outer shape like a well-known nut, thereby forming a tool hooking surface (engaging portion) 13 with which a general-purpose tightening tool can be engaged. 8 and the tool holder 9 have an inner diameter of bolt 2
Has a diameter that allows the male screw 6 to be loosely inserted. The breaking portion 8 has a strength to break when the tightening torque acting on the tool hooking portion 9 exceeds a predetermined value. When an even number of the engaging portions 11 is provided, for example, four, an even number of the engaging portions are provided at positions not facing each other so that the nut 1 cannot be rotated by a general-purpose fastening tool.

In the first embodiment, the female screw 12 provided on the nut body 7 is screwed to the male screw 6 of the bolt 2, and a general-purpose tightening tool is engaged with the tool hooking surface 13 of the tool hook 9 and rotated. And the member between the nut 1 and the bolt 2 can be fastened. In this case, since the nut 1 can be tightened by a general-purpose tightening tool, the tightening operation is easy. If the tightening torque of the nut 1 acting on the tool hook 9 exceeds a predetermined value determined according to the nut 1, the break portion 8 is broken, so that the tightening can be performed with a substantially constant torque, and excessive torque can be obtained. The nut 1 is not tightened with a small torque.

When the breaking portion 8 breaks, the tool hook 9 is separated from the bolt 2, and there is no engaging portion on the outer peripheral surface of the nut body 7 with which a general-purpose tightening tool can be engaged. Since the nut body 7 cannot be rotated, loosening and removal of the nut 1 due to mischief can be prevented. When the tightening of the nut body 7 is loosened for any reason, the nut body 7 is re-engaged by engaging the engaging portion of the dedicated tightening tool with the engaging portion 11 provided on the outer peripheral surface of the nut body 7 and rotating. Can be tightened. If the engaging portion 11 provided on the nut main body 7 is eliminated, the nut main body 7 cannot be tightened again, but can be inexpensive.

FIGS. 5 to 8 show a gear lock bolt according to a second embodiment of the present invention.
Has a shape in which there is no engaging portion with which a general-purpose tightening tool can be engaged with the head 18 (in the illustrated example, a frustoconical shape), and a nut 16 is screwed to a tip portion of the shaft portion 5. Male screw 6 is formed (see FIG. 8).

The nut 16 includes a nut body 20, a lock nut portion 21, and a break portion 22 therebetween. These members are integrally formed of a suitable material as in the first embodiment. I have. The nut body 20 and the lock nut portion 21 have a shape having no engaging portion on the outer peripheral surface with which a general-purpose tightening tool can engage (in the illustrated example, a truncated cone), and the diameter thereof is reduced by appropriate means such as cutting. The broken annular portion 22 has the strength to break when the tightening torque exceeds a predetermined value, similarly to the broken portion 8 of the first embodiment.

On the outer peripheral surfaces of the nut body 20 and the lock nut portion 21, a plurality (three in the illustrated example) of a depth which can be engaged with a dedicated tightening tool is set as an example of the engaging portion 24. The shallow engagement groove has a bolt 1
A female screw 25 with which the male screw 6 is screwed is formed. When the engaging portion 24 is formed as an engaging groove, the groove width can be changed according to the size of the nut 16 and the location to be used.

In the second embodiment, the female screw 25 provided on the nut 16 is screwed onto the male screw 6 of the bolt 17, and a dedicated tightening tool is engaged with the engaging portion 24 provided on the outer peripheral surface of the nut 16 for rotation. Then, the member between the bolt 17 and the nut 16 can be fastened. In this case, if the tightening torque of the nut 16 exceeds a predetermined value, the breaking portion 22 breaks,
The tightening torque can be made substantially constant. Also,
The lock nut portion 21 screwed to the male screw 6 of the bolt 17 can prevent the nut body 20 from being loosened as a double nut due to the breakage of the break portion 22.

For some reason, the tightening of the nut body 20 may become loose, or the bolt 17 and / or the nut 16 may be loosened.
When exchanging is performed, if a dedicated tightening tool is engaged with the engaging portion 24 provided on the nut body 20 and the lock nut portion 21, it is possible to retighten or exchange these members. Other operations of the second embodiment are the same as those of the first embodiment.

[Brief description of the drawings]

FIG. 1 is a front view of a first embodiment.

FIG. 2 is a plan view of the same.

FIG. 3 is a rear view of the same.

FIG. 4 is a sectional view showing a state in which the bolt is screwed.

FIG. 5 is a front view of the second embodiment.

FIG. 6 is a plan view of the same.

FIG. 7 is a rear view of the same.

FIG. 8 is a sectional view showing a state in which the bolt is screwed.

[Explanation of symbols]

 1,16 Nut 2,17 Bolt 4,18 Head 6 Male Thread 7,20 Nut Body 8,22 Breakage 9 Tool Hook 11,24 Engagement 12,25 Female Thread 21 Lock Nut

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[Procedure amendment]

[Submission date] March 26, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Nuts and bolts / nuts

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nut and a bolt / nut.

[0002]

2. Description of the Related Art Fastening mechanisms using bolts and nuts are well known without particular examples. The well-known fastening mechanism using the above-mentioned bolt and nut has an advantage that it can be fastened with a general-purpose fastening tool such as a spanner, a wrench, a screwdriver, or the like, but it is difficult to tighten with a fixed tightening torque. And / or the nut itself may be damaged. Further, if the tightening torque is reduced to avoid damage to these members, the tightening may be loosened over time.

Further, since a general-purpose tightening tool can be used, it is difficult to prevent loosening and removal of the nut due to mischief. Particularly, if the tightening of the nut on a transmission tower or a guardrail is loosened or removed. May cause unexpected accidents.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a nut and a bolt / nut which can make the tightening torque substantially constant and prevent loosening or removal of the tightening due to mischief or the like. Is to do.

[0005]

In order to solve the above-mentioned problems, a nut according to the present invention has a female screw to be screwed into a male screw of a bolt, and has no engaging portion on its outer surface with which a general-purpose tightening tool can be engaged. A nut body having an engaging portion that only a dedicated tightening tool can engage with; a tool hook having an engaging portion into which the male screw can be loosely inserted and engaging with a general-purpose tightening tool; And a nut formed integrally with the breaking portion; wherein the breaking portion has strength enough to break when a tightening torque acting on the tool hook portion exceeds a predetermined value. .

In order to solve the same problem, a nut according to the present invention has a female screw to be screwed into a male screw of a bolt, and has no engaging portion on its outer surface with which a general-purpose tightening tool can be engaged. A nut body and a lock nut portion having an engagement portion with which only the engagement is possible; and a break portion between these members; and a tightening torque acting on the lock nut portion. Has a strength to be broken when exceeds a predetermined value, and the lock nut portion functions as a double nut for preventing loosening by breaking of the broken portion.

In order to further solve the same problem, a bolt / nut according to the present invention is characterized by comprising a bolt having no engaging portion with which a general-purpose fastening tool can be engaged;

[0008]

The function and effect of the invention are as follows.
A female screw formed on the nut body is screwed onto a male screw of a bolt having no engaging portion with which the general-purpose tightening tool can be engaged with the head, and the general-purpose tightening tool is engaged with the engaging portion of the tool hook portion. By rotating, appropriate members between the bolt and the nut can be tightened. In this case, the nut can be fastened to the bolt by a general-purpose fastening tool, so that the nut can be easily tightened.

If the tightening torque exceeds a predetermined value, the breakage portion breaks, so that the nut can be tightened with a substantially constant torque suitable for fastening, thereby eliminating excessive tightening and insufficient tightening force. In addition, when the tool hook is separated from the nut body due to the breakage of the break, there is no engaging portion on the outer surface of the nut body with which a general-purpose tightening tool can be engaged, so that loosening and removal of the nut due to mischief can be prevented. it can. In addition, dedicated to the outer surface of the nut body
Tightening the only tool is to have the engaging portion can engage the
The nut body is loosened for some reason
The nut body with a special tightening tool.
Can be attached.

[0010] "General purpose tightening tool" in this specification
A tool that can tighten or loosen bolts and nuts, such as a well-known spanner or wrench, means that there is no engaging portion that can be used by general-purpose tightening tools. This does not mean only a head that does not have an engaging portion with which a general-purpose fastening tool can be engaged, but a head in which an arbitrary-shaped head cannot be rotated in an insertion hole, or a bolt whose head is embedded in concrete or the like. And the bolt itself cannot be rotated.

[0011] The nut according to the second aspect of the present invention provides a general-purpose nut on the head when the dedicated tightening tool is engaged with an engaging portion provided on the outer surface of the nut and can be engaged only by the dedicated tightening tool and the tool is rotated. The nut can be fastened to a bolt having no engaging portion with which the tightening tool can be engaged. If the tightening torque exceeds a predetermined value, the broken part will break,
The nut can be tightened with a substantially constant torque suitable for tightening, and excessive tightening and insufficient tightening can be eliminated.

Further, when the break portion breaks, the lock nut portion separated by the break functions as a double nut, so that the nut body can be prevented from loosening. further,
Since the engaging portions that can be engaged only by the dedicated rotary tool are provided on the outer surfaces of the nut body and the lock nut portion, when the fastening of these members is loosened for some reason, the fastening can be performed by the dedicated fastening tool.

[0013]

1 to 4 show a first embodiment of the present invention in which a gear lock bolt is used. A bolt 2 on which a nut 1 is screwed is provided with a head 4 using a general-purpose tightening tool. A male screw 6 having a shape having no engaging portion that can be fitted (a ball band in the illustrated example), and a nut 1 screwed to a tip portion of the shaft portion 5.
Are formed (see FIG. 4).

The nut 1 has a shape in which the outer peripheral surface has no engaging portion with which a general-purpose tightening tool can engage (a ball band in the illustrated example), and is reduced in diameter by an appropriate means such as cutting. Annular breaking portion 8 and nut body 7 of the breaking portion
And a tool holder 9 on the opposite side, which are integrally formed of a suitable material such as mild steel. On the outer peripheral surface of the nut body 7, a shallow engaging groove as an example of the engaging portion 11 for engaging a dedicated tightening tool (not shown) is arranged at a circumferential interval. A plurality (three in the illustrated example) is formed in the axial direction, and a female screw 12 to which the male screw 6 of the bolt 2 is screwed is formed at the center.

The illustrated tool hook 9 has a regular hexagonal outer shape like a well-known nut, thereby forming a tool hooking surface (engaging portion) 13 with which a general-purpose tightening tool can be engaged. 8 and the tool holder 9 have an inner diameter of bolt 2
Has a diameter that allows the male screw 6 to be loosely inserted. The breaking portion 8 has a strength to break when the tightening torque acting on the tool hooking portion 9 exceeds a predetermined value. When an even number of the engaging portions 11 is provided, for example, four, an even number of the engaging portions are provided at positions not facing each other so that the nut 1 cannot be rotated by a general-purpose fastening tool.

In the first embodiment, the female screw 12 provided on the nut body 7 is screwed to the male screw 6 of the bolt 2, and a general-purpose tightening tool is engaged with the tool hooking surface 13 of the tool hooking portion 9 and rotated. And the member between the nut 1 and the bolt 2 can be fastened. In this case, since the nut 1 can be tightened by a general-purpose tightening tool, the tightening operation is easy. If the tightening torque of the nut 1 acting on the tool hook 9 exceeds a predetermined value determined according to the nut 1, the break portion 8 is broken, so that the tightening can be performed with a substantially constant torque, and excessive torque can be obtained. The nut 1 is not tightened with a small torque.

When the breaking portion 8 breaks, the tool hook 9 is separated from the bolt 2 and there is no engaging portion on the outer peripheral surface of the nut body 7 with which a general-purpose tightening tool can be engaged. Since the nut body 7 cannot be rotated, loosening and removal of the nut 1 due to mischief can be prevented. When the tightening of the nut body 7 is loosened for any reason, the nut body 7 is re-engaged by engaging the engaging portion of the dedicated tightening tool with the engaging portion 11 provided on the outer peripheral surface of the nut body 7 and rotating. Can be tightened .

FIGS. 5 to 8 show a gear lock bolt according to a second embodiment of the present invention.
Has a shape in which there is no engaging portion with which a general-purpose tightening tool can be engaged with the head 18 (in the illustrated example, a frustoconical shape), and a nut 16 is screwed to a tip portion of the shaft portion 5. Male screw 6 is formed (see FIG. 8).

The nut 16 includes a nut body 20, a lock nut portion 21, and a break portion 22 therebetween, and these members are integrally formed of a suitable material as in the first embodiment. I have. The nut body 20 and the lock nut portion 21 have a shape having no engaging portion on the outer peripheral surface with which a general-purpose tightening tool can engage (in the illustrated example, a truncated cone), and the diameter thereof is reduced by appropriate means such as cutting. The broken annular portion 22 has the strength to break when the tightening torque exceeds a predetermined value, similarly to the broken portion 8 of the first embodiment.

On the outer peripheral surfaces of the nut body 20 and the lock nut portion 21, a plurality (three in the illustrated example) of a depth that can be engaged with a dedicated tightening tool has a depth as an example of the engaging portion 24. The shallow engagement groove has a bolt 1
A female screw 25 with which the male screw 6 is screwed is formed. When the engaging portion 24 is formed as an engaging groove, the groove width can be changed according to the size of the nut 16 and the location to be used.

In the second embodiment, the female screw 25 provided on the nut 16 is screwed to the male screw 6 of the bolt 17, and a dedicated tightening tool is engaged with the engaging portion 24 provided on the outer peripheral surface thereof to rotate. Then, the member between the bolt 17 and the nut 16 can be fastened. In this case, if the tightening torque of the nut 16 exceeds a predetermined value, the breaking portion 22 breaks,
The tightening torque can be made substantially constant. Also,
The lock nut portion 21 screwed to the male screw 6 of the bolt 17 can prevent the nut body 20 from being loosened as a double nut due to the breakage of the break portion 22.

For some reason, the tightening of the nut body 20 is loosened, and the bolt 17 and / or the nut 16
When exchanging is performed, if a dedicated tightening tool is engaged with the engaging portion 24 provided on the nut body 20 and the lock nut portion 21, it is possible to retighten or exchange these members. Other operations of the second embodiment are the same as those of the first embodiment.

[Brief description of the drawings]

FIG. 1 is a front view of a first embodiment.

FIG. 2 is a plan view of the same.

FIG. 3 is a rear view of the same.

FIG. 4 is a sectional view showing a state in which the bolt is screwed.

FIG. 5 is a front view of the second embodiment.

FIG. 6 is a plan view of the same.

FIG. 7 is a rear view of the same.

FIG. 8 is a sectional view showing a state in which the bolt is screwed.

[Description of Signs] 1,16 Nut 2,17 Bolt 4,18 Head 6 Male Thread 7,20 Nut Body 8,22 Breaking Part 9 Tool Hook Part 11,24 Engaging Part 12,25 Female Thread 21 Lock Nut

Claims (4)

[Claims] 1. A female screw having a female screw engaged with a male screw of a bolt,
A nut body having no engaging portion on its outer surface with which a general-purpose tightening tool can engage; a tool hook having an engaging portion into which the male screw can be loosely inserted and with which a general-purpose tightening tool can engage; And a nut formed integrally with the nut, wherein the broken portion has a strength to break when a tightening torque acting on the tool hook portion exceeds a predetermined value. Nuts to do. 2. A female screw having a female screw engaged with a male screw of the bolt,
There is no engaging part on the outer surface where a general-purpose tightening tool can engage,
A nut body having an engaging portion that only a dedicated tightening tool can engage with; a tool hook having an engaging portion into which the male screw can be loosely inserted and engaging with a general-purpose tightening tool; A breaking part; and a nut formed integrally with the breaking part, wherein the breaking part has a strength to be broken when a tightening torque acting on the tool holding part exceeds a predetermined value. Nuts to do. 3. A female screw which is screwed into a male screw of the bolt,
There is no engaging part on the outer surface where a general-purpose tightening tool can engage,
A nut formed integrally with a nut body and a lock nut portion having an engagement portion that can be engaged only by a dedicated tightening tool; and a break portion between these members, wherein the break portion is formed on the lock nut portion. A nut having a strength such that it is broken when an acting tightening torque exceeds a predetermined value, and the lock nut functions as a double nut for preventing loosening when the broken portion is broken. 4. A bolt and nut, comprising: a bolt having no engaging portion with which a general-purpose tightening tool can engage; and a nut according to any one of claims 1 to 3.