JP2006316830A - Fastening structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compacter fastening structure capable of easily cancelling fastening between fastened members while securing sufficient force of fastening the fastened members to each other. <P>SOLUTION: In the fastening structure 10, a split stopper 31 is applied onto the outer peripheries of first and second nut pieces 23, 24 and the split stopper 31 and the nut pieces 23, 24 are fitted into a ring member 25 until the nut pieces 23, 24 are integrated therewith to form a clamping member 20 which is connectable to a bolt 13. The ring member 25 is formed of a shape memory material which produces contractive deforming force with heat, and the ring member 25 has a vulnerable portion 26 breakable when the contractive deforming force is produced. The breakage of the vulnerable portion 26 cancels fastening between the first and second fastened members 11, 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fastening structure in which a bar-shaped member is inserted through a plurality of members to be fastened and the members to be fastened are fastened by clamping members provided at both ends of the bar-shaped member.

For example, in an assembly such as an automobile, a plurality of members are fastened by a fastening structure such as a bolt / nut or a rivet.
A reusable member is used as a component member of the assembly. When the assembly is disposed of, the assembly is disassembled and the reusable member is taken out.

Here, in order to disassemble the assembly and take out a reusable member, it is necessary to remove the fastening member from the constituent members of the assembly.
However, it takes time to remove the fastening member from the constituent members of the assembly, and it is difficult to easily remove a reusable member from the assembly.
As fastening structures for solving this problem, the following first to third fastening structures are known.

The first fastening structure is a fastening member (clip) formed of a shape memory material (see, for example, Patent Document 1).
In this fastening structure, a pair of leg portions are extended from a head portion of a fastening member (clip) at a predetermined interval, and protrusions are provided at the tips of the pair of leg portions, respectively.
The leg portion of the fastening member is stored in a shape that can be fastened in a heated state, and is secondarily processed into a shape that can be fastened in a normal temperature state.

According to the fastening member of Patent Document 1, a pair of legs are inserted into the mounting holes of the fastened member, the respective protrusions are locked to the periphery of the mounting hole, and the fastened member is sandwiched between the pair of protrusions and the head. To conclude.
When releasing the fastening of the member to be fastened, the fastening member is heated and restored to a shape capable of releasing the fastening. Thereby, a pair of protrusion is removed from the periphery of an attachment hole, and the fastening of a to-be-fastened member is cancelled | released.

The second fastening structure is a fastening member (header and nut) formed of a shape memory material (for example, see Patent Document 2).
In this fastening structure, a fastening member (header and nut) is formed in a ring shape, and a slit is formed in the ring-shaped member.
The fastening member is stored in a shape that can be released in a heated state, and is secondarily processed into a shape that can be fastened in a normal temperature state.

According to the fastening member of Patent Literature 2, after inserting the screw shaft into the mounting hole of the fastened member, the fastening member is locked to both ends of the screw shaft, and the fastened member is fastened by the pair of fastening members.
When releasing the fastening of the member to be fastened, the fastening member is heated and restored to a shape capable of releasing the fastening. Thereby, the slit of a fastening member expands greatly, a fastening member is removed from a screw shaft, and the fastening of a to-be-fastened member is cancelled | released.

The fastening structure of the third means is a structure in which a fastening member (bolt) is provided with a stress concentration portion, and a driving member for applying stress to the stress concentration portion is formed of a shape memory material (for example, Patent Document 3). reference.).
This drive member is formed, for example, in a cylindrical shape, is fitted into a fastening member (bolt), has one end abutting on the nut and the other end abutting on the member to be fastened.
The driving member is compressed and deformed in advance in a normal temperature state and incorporated in the fastening member, and is restored to a memory shape in a heating state.

  According to Patent Document 3, the driving member is heated to restore the memory shape, and the stress concentration portion is applied to the fastening member (bolt) with this restoring force. Thereby, a stress concentration part fractures | ruptures and the fastening of a to-be-fastened member is cancelled | released.

JP 2002-5124 A JP 2003-301815 A US Pat. No. 5,119,555

However, in the fastening structure of Patent Document 1, the fastening member (clip) is fastened to the fastening hole of the fastening member simply by sandwiching the fastening member between the pair of protrusions and the head.
For this reason, in the fastening structure of Patent Document 1, it is difficult to ensure a sufficient fastening force.

Moreover, the fastening structure of patent document 2 forms a fastening member (header and nut) in a ring shape, and the slit is formed in the ring-shaped member. Therefore, the fastening member (header and nut) cannot be firmly locked to the screw shaft.
For this reason, in the fastening structure of Patent Document 2, it is difficult to ensure a sufficient fastening force.

Furthermore, in the fastening structure of Patent Document 3, it is necessary to fit the driving member into the fastening member (bolt), one end abuts against the nut, and the other end abuts against the member to be fastened. Protruding.
For this reason, it is necessary to ensure a relatively large space for disposing the drive member in the vicinity of the fastened member, and the use location of the fastening structure of Patent Document 1 is limited.

  An object of the present invention is to provide a fastening structure that can easily release the fastening of the member to be fastened, sufficiently ensure the fastening force of the member to be fastened, and achieve compactness.

  The invention according to claim 1 is a fastening structure in which a rod-like member is inserted through a plurality of members to be fastened, and fastened by clamping the member to be fastened by sandwiching members provided at both ends of the rod-like member, and the rod-like member And at least one member of the members constituting the sandwiching member is formed of a functional material that generates a contraction deformation force by applying energy, and the member formed of the functional member has a contraction deformation force by the energy. It is characterized in that a weakened portion that breaks when a sag is generated and that the fastened member can be released by breaking the weakened portion.

  Here, as the functional material, for example, a shape memory material such as a shape memory alloy, a shape memory resin, or a magnetic shape memory alloy, or a functional element such as a magnetostrictive element, a piezoelectric (electrostrictive) element, or an optical strain element. is there.

According to the first aspect, at least one member among the members constituting the rod-shaped member and the sandwiching member is formed of a functional material that generates a contraction deformation force by applying energy. In addition, a member made of a functional material is provided with a fragile portion that breaks when a shrinkage deformation force is generated.
Thereby, the fastening of a to-be-fastened member can be easily cancelled | released by applying energy to the member formed with the functional material, and breaking a weak part.

Furthermore, the member formed with the functional material can be integrated by providing the weak member with the member formed of the functional material.
Therefore, it is not necessary to previously provide a separation part such as a slit in a member formed of a functional material. Thus, the rigidity of a member can be improved by integrating the member formed with the functional material.
As a result, the member to be fastened can be strongly held by the member formed of the functional material, and the fastening force of the member to be fastened can be sufficiently secured.

In addition, a fastening member that directly fastens the fastened member is formed of a functional material, and the fastening member includes a fragile portion.
Therefore, it is possible to break the fastening member itself by applying energy to the fastening member formed of the functional material.
As a result, in order to break the fastening member that directly fastens the member to be fastened, it is not necessary to form a separate member with a functional material and provide it separately, so the number of members can be reduced, and the fastening mechanism is compact. Can be achieved.

  The fastening structure according to claim 2, wherein the fastening member is fastened by inserting the fastening member through the plurality of fastening members and sandwiching the fastening member with the clamping members provided at both ends of the sticking member. At least one of the clamping members provided in the above can be connected to the rod-shaped member by integrating a plurality of divided members with a connecting member, and the connecting member can be contracted and deformed by applying energy. A member formed of a functional material that is generated, and a member formed of the functional member is provided with a fragile portion that is broken when a shrinkage deformation force is generated by the energy, and the cleated member is broken by breaking the fragile portion. It is possible to release the fastening.

A plurality of divided members are configured to be integrated with a connecting member, and the connecting member is formed of a functional material that generates contraction deformation force by applying energy. The rigidity of the clamping member can be increased by integrating the plurality of divided members with the connecting member.
As a result, the fastened member can be strongly clamped by the clamping member, and the fastening force of the fastened member can be sufficiently secured.

Further, the fragile portion is provided in the connecting member, and the fragile portion is broken when the connecting member generates a contraction deformation force.
Thereby, a some division | segmentation member isolate | separates and remove | deviates from a rod-shaped member, and the fastening of a to-be-fastened member can be cancelled | released easily.

In addition, by forming a connecting member that integrates a plurality of divided members with a connecting member from a functional material, the connecting member can be broken by applying energy.
Therefore, in order to break the connecting member, it is not necessary to separately provide another member with a functional material. Thereby, the number of members can be suppressed, and the fastening mechanism can be made compact.

  A third aspect of the present invention is a fastening structure in which a bar-shaped member is inserted through a plurality of members to be fastened and fastened by sandwiching the members to be fastened by sandwiching members provided at both ends of the bar-shaped member. Is formed of a functional material that generates a shrinkage deformation force, and the member formed of the functional member includes a weakened portion that breaks when the shrinkage deformation force is generated by the energy. The fastening of the member to be fastened can be released by breaking.

The rod-like member that fastens the member to be fastened is made of a functional material that generates contraction deformation force by applying energy. And a weak part was provided in the rod-shaped member, and when the contraction deformation force was generated in the rod-shaped member, the weak part was broken.
Thus, the fastening of the member to be fastened can be easily released by breaking the rod-like member.

Furthermore, a rod-shaped member can be integrated by providing a weak part in a rod-shaped member. The rigidity can be increased by integrating the rod-shaped members.
Thereby, it becomes possible to clamp | tighten a to-be-fastened member strongly with a rod-shaped member, and can fully ensure the fastening force of a to-be-fastened member.

In addition, by forming the rod-like member for fastening the member to be fastened with a functional material, the rod-like member can be broken by applying energy.
Therefore, in order to break the rod-shaped member, it is not necessary to separately provide another member with a functional material. Thereby, the number of members can be suppressed, and the fastening mechanism can be made compact.

  5. The functional material according to claim 4, wherein the functional material is a shape memory material, and the at least one member is a member formed so that a tensile force can be applied when the fastened member is fastened. .

The functional material was a shape memory material. And when fastening a to-be-fastened member with the fastening member formed with the shape memory material, the tensile force was given to this fastening member.
Therefore, it is not necessary to preliminarily apply a tensile force to the fastening member formed of the shape memory material before fastening the fastened member.

  This makes it possible to omit a step of applying a tensile force in advance to a fastening member formed of a shape memory material by using, for example, a tension jig when fastening a member to be fastened, and simplify the assembly process. Can be achieved.

  In the invention which concerns on Claim 1, there exists an advantage that the fastening of a to-be-fastened member can be easily cancelled | released by applying energy to the fastening member formed with the functional material, and breaking a weak part.

  Furthermore, in the invention which concerns on Claim 1, there exists an advantage that the fastening force of a to-be-fastened member can fully be ensured by integrating the fastening member formed with the functional material and improving rigidity.

  In addition, the invention according to claim 1 is advantageous in that the fastening mechanism can be made compact because it is not necessary to provide a separate member for breaking the fastening member.

  In the invention which concerns on Claim 2, there exists an advantage that the fastening force of a to-be-fastened member can fully be ensured by integrating a several division member with a connection member, and clamping a to-be-fastened member strongly with a clamping member. .

  Furthermore, in the invention according to claim 2, there is an advantage that by separating the plurality of divided members by breaking the fragile portion, the divided members can be removed from the rod-shaped member and the fastening of the fastened member can be easily released. is there.

  In addition, the invention according to claim 2 has an advantage that the fastening mechanism can be made compact because it is not necessary to provide a separate member for breaking the connecting member.

  In the invention which concerns on Claim 3, there exists an advantage that the fastening of a to-be-fastened member can be easily cancelled | released by generating shrinkage deformation force to a rod-shaped member and breaking a weak part.

  Further, the invention according to claim 3 has an advantage that the fastening force of the fastened member can be sufficiently secured by strongly clamping the fastened member with the integrated rod-like member.

  In addition, the invention according to claim 3 has an advantage that the fastening mechanism can be made compact because it is not necessary to provide a separate member for breaking the rod-shaped member.

  In the invention according to claim 4, when fastening the member to be fastened, for example, an assembling step is performed by omitting a step of applying a tensile force in advance to the fastening member formed of the shape memory material by using a pulling jig. There is an advantage that simplification can be achieved.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a perspective view showing a fastening structure (first embodiment) according to the present invention, and FIG. 2 is a cross-sectional view showing the fastening structure according to the first embodiment.
The fastening structure 10 has a bolt (rod-like member) 13 inserted through the mounting hole 11a of the first fastened member (fastened member) 11 and the mounting hole 12a of the second fastened member (fastened member) 12, and the mounting hole 11a. A clamping member (one of the clamping members provided at both ends) 20 is screwed to the bolt 13 protruding from the screw 13, so that the clamping member 20 and the head of the bolt 13 (a clamping member provided at both ends) Among them, the first and second fastened members 11 and 12 are clamped and fastened with the other clamping member 15.

  Furthermore, the fastening structure 10 covers the outer periphery of the first and second nut pieces (a plurality of divided members) 23 and 24 with the division stopper 31 and the division stopper 31 and the first and second nut pieces 23 and 24 as rings. The first and second nut pieces 23 and 24 are integrated into a member (connecting member) 25 to form a sandwiching member 20, and the sandwiching member 20 can be coupled to the bolt 13.

In addition, in the fastening structure 10, the ring member 25 is formed of a shape memory material (functional material) that generates shrinkage deformation force by applying heat (energy), and the ring member 25 formed of this shape memory material The fragile portion 26 that can be broken when the contraction deformation force is generated is provided, and the fragile portion 26 is broken so that the fastening of the first and second fastened members 11 and 12 can be released.
The split nut 22 is formed by overlapping the first and second nut pieces 23 and 24 at the split portion 29.

  In addition, the fastening structure 10 includes an annular heating unit 35 on the outer periphery of the ring member 25, and heat is applied to the ring member 25 by the heating unit 35 to generate a contraction deformation force on the ring member 25. It is a thing.

The 1st to-be-fastened member 11 is a steel flat plate material provided with the attachment hole 11a as an example. The 2nd to-be-fastened member 12 is a steel flat plate provided with the attachment hole 12a as an example.
The bolt 13 includes a rod portion 14 that can be inserted into the mounting holes 11a and 12a, the rod portion 14 includes a screw portion 14a, and a head portion 15 at a base end (one of both end portions of the rod-shaped member) 14b. It is provided.

The head 15 is a part that protrudes outward from the peripheral wall 12b of the mounting hole 12a of the second fastened member 12 and is formed in a hexagonal shape.
When the bolt 13 is inserted into the mounting hole 12a, the head 15 comes into contact with the peripheral wall 12b of the mounting hole 12a.

The clamping member 20 includes a split nut 22 that can be screw-coupled to the threaded portion 14 a of the bolt 13, a split stopper 31 outside the split nut 22, and a ring member 25 outside the split stopper 31.
The clamping member 20 is provided on a threaded portion (the other of both end portions of the rod-shaped member) 14 a of the bolt 13.

FIG. 3 is an exploded perspective view showing the fastening structure according to the first embodiment.
The split nut 22 is formed by forming the left half portion with the first nut piece 23 and forming the right half portion with the second nut piece 24.
That is, the split nut 22 is obtained by overlapping the first and second nut pieces 23 and 24 by the split portion 29. The split nut 22 has a female screw portion 22a at the center, a hexagonal portion 22b in the upper half, and a cylindrical portion 22c in the lower half.
The hexagonal portion 22b is a portion that protrudes outside the cylindrical portion 22c and is formed in a hexagonal shape. The cylindrical portion 22c is a portion whose outer periphery is formed in a circular cross section.

A split stopper 31 is provided outside the split nut 22.
The split stopper 31 is formed by forming a front half portion with a first stopper piece 32 and a second half portion with a second stopper piece 33. The first and second stopper pieces 32 and 33 are overlapped by the dividing portion 34 to form the dividing stopper 31.
The division stopper 31 is formed in an annular shape, includes a flange 31a projecting outward at the upper end portion, and is formed in a tapered shape so that the outer circumference 31c gradually decreases in diameter from the flange 31a toward the lower end portion 31b.

The first stopper piece 32 is a member formed in a semicircular arc shape, and the inner periphery of the first stopper piece 32 comes into contact with the outer periphery of the cylindrical portion 22 c by being fitted into the cylindrical portion 22 c of the split nut 22.
Similar to the first stopper piece 32, the second stopper piece 33 is a member formed in a semicircular arc shape, and the inner circumference contacts the outer circumference of the cylindrical portion 22c by fitting into the cylindrical portion 22c of the split nut 22. It is a member.
In a state where the first and second stopper pieces 32 and 33 are fitted into the cylindrical portion 22 c, the first and second stopper pieces 32 and 33 are overlapped by the dividing portion 34.

Here, when the first and second stopper pieces 32 and 33 are fitted into the split nut 22, the split portion 34 of the first and second stopper pieces 32 and 33 is moved with respect to the split portion 29 of the split nut 22. To make them almost orthogonal.
The reason why the dividing unit 34 is substantially orthogonal to the dividing unit 29 will be described in detail with reference to FIG.

A ring member 25 is provided outside the division stopper 31.
The ring member 25 is a ring-shaped member made of a shape memory material. The ring member 25 has a constant height and is tapered so that the inner circumference 27 gradually decreases in diameter from the upper end 25a toward the lower end 25b. Yes.
The ring member 25 includes a fragile portion 26 having a reduced thickness by forming a notch 28a in the outer periphery 28.
The reason why the outer periphery 31c of the split stopper 31 is tapered and the inner periphery 27 of the ring member 25 is tapered will be described in detail with reference to FIGS.

As the shape memory material forming the ring member 25, a shape memory alloy or a shape memory resin that generates a contraction deformation force by applying heat (energy) is applicable, and a Ti—Ni alloy is used as an example.
For example, a magnetic shape memory alloy can be used as a shape memory material in place of the shape memory alloy or the shape memory resin.

A magnetic shape memory alloy is a material that undergoes shrinkage deformation when a magnetic field (energy) is applied. As an example, a Ni—Mn—Ga alloy is used.
When the ring member 25 is formed of a magnetic shape memory alloy, a magnetic field applying unit is provided instead of the heating unit 35.

A heating means 35 is provided on the outer periphery of the ring member 25.
The heating means 35 is a ring-shaped member wound around the entire outer periphery 28 of the ring member 25. For example, a heater (not shown) is provided inside.
This heating means 35 is elastically deformable. The ring-shaped heating means 35 can be expanded in diameter by elastic deformation.

The heating means 35 is connected to a battery (not shown) by wire harnesses 37 and 37, for example. The heater is heated by keeping the heating means 35 in an energized state, and the ring member 25 is heated by the heat generated from the heater.
Note that the heating means 35 is not limited to a ring-shaped member. For example, a part divided into a plurality of parts may be provided on the outer periphery 28 of the ring member 25.

Next, the assembly | attachment process of the fastening structure 10 is demonstrated based on FIGS.
FIGS. 4A and 4B are views for explaining an example in which the split nut of the fastening structure according to the first embodiment is set on a member to be fastened.
In (a), the 1st to-be-fastened member 11 is piled up on the 2nd to-be-fastened member 12, and the ring member 25 and the heating means 35 are mounted on the 1st to-be-fastened member 11. FIG.
The ring member 25 has an upper end portion 25a having an inner diameter D1.
The heating means 35 is wound around the outer periphery of the ring member 25.

  The first and second nut pieces 23 and 24 are overlapped by the dividing portion 29 to form the divided nut 22. The first and second stopper pieces 32 and 33 are fitted into the cylindrical portion 22c (see FIG. 2) of the split nut 22.

The first and second stopper pieces 32 and 33 are overlapped by the dividing portion 34 to form the dividing stopper 31. At this time, the dividing unit 34 is substantially orthogonal to the dividing unit 29.
In this state, the female screw portion 22a of the split nut 22 is arranged coaxially with the mounting holes 11a and 12a, and the split nut 22 and the split stopper 31 are placed on the ring member 25 as indicated by an arrow A.

  In (b), the threaded portion 14a of the bolt 13 is inserted as shown by an arrow B from the mounting hole 12a (see FIG. 4A) of the second fastened member 12.

FIGS. 5A and 5B are diagrams illustrating an example in which a bolt is screwed to the split nut of the fastening structure according to the first embodiment.
In (a), the hexagonal portion 22b of the split nut 22 placed on the ring member 25 is held in a state where it does not rotate with a tool (not shown) such as a socket wrench.
The threaded portion 14a of the bolt 13 is projected from the mounting hole 11a of the first fastened member 11 and is aligned with the female threaded portion 22a.

In this state, by rotating the bolt 13 as shown by the arrow C, the screw portion 14a is screwed to the female screw portion 22a.
The split nut 22 descends as shown by arrow D. The hexagonal portion 22b of the split nut 22 pushes down the flange 31a, so that the split stopper 31 is lowered together with the split nut 22 as shown by an arrow D.
The outer periphery 31 c of the division stopper 31 enters the ring member 25 along the inner periphery 27.

In (b), when the outer periphery 31c enters the inner periphery 27, the outer periphery 31c radially presses the inner periphery 27 as shown by arrows.
Therefore, the diameter of the ring member 25 gradually increases according to the amount that the outer periphery 31 c enters along the inner periphery 27.

FIGS. 6A and 6B are diagrams illustrating an example in which a fastened member is fastened by the fastening structure according to the first embodiment.
In (a), the end surface of the cylindrical portion 22 c of the split nut 22 abuts on the first fastened member 11, and the outer periphery 31 c sufficiently enters the inner periphery 27. The division stopper 31 and the division nut 22 are fastened by the ring member 25.

Therefore, the first and second nut pieces 23 and 24 constituting the split stopper 31 are integrated, and the first and second stopper pieces 32 and 33 (first stopper piece 32 constituting the split nut 22 are integrated). (See FIG. 4A).
At the same time, the split stopper 31, the split nut 22, and the ring member 25, that is, the clamping member 20 are integrated.

In this manner, the split nut 22 and the split stopper 31 are fitted into the ring member and integrated.
Therefore, the split nut 22 and the split stopper 31 can be easily integrated simply by fitting the split nut 22 and the split stopper 31 into the ring member 25.

And it clamp | tightens by clamping the 1st, 2nd to-be-fastened members 11 and 12 with the clamping member 20 and the head 15 of the volt | bolt 13. FIG.
By integrating the split nut 22 with the ring member 25, the rigidity of the clamping member 20 can be increased.
As a result, the first and second fastened members 11 and 12 can be strongly held by the sandwiching member 20, and the fastening force of the first and second fastened members 11 and 12 can be sufficiently secured. Can do.

Further, in a state where the end surface of the cylindrical portion 22 c is in contact with the first fastened member 11, the outer periphery 31 c sufficiently enters the inner periphery 27.
Thereby, the diameter of the ring member 25 is expanded, and the inner diameter of the upper end portion 25a becomes D2. The ring member 25 is expanded in diameter and extends in the circumferential direction.

Thus, when the first and second nut pieces 23 and 24 are integrated, that is, when the first and second members to be fastened 11 and 12 are fastened, the split nut 22 (specifically, The ring member 25 can be extended in the circumferential direction by means of the dividing stopper 31).
Therefore, before the first and second fastened members 11 and 12 are fastened, as an example, it is not necessary to stretch the ring member 25 in the circumferential direction (so-called secondary processing) using a pulling jig. . Thereby, the assembly process can be simplified.

  In (b), the screw portion 14 a of the bolt 13 is screwed to the female screw portion 22 a of the split nut 22, whereby the first and second nut pieces 23 and 24 constituting the split nut 22 are moved from the split portion 29 to the arrow. Try to leave like.

Therefore, when the first and second stopper pieces 32 and 33 are fitted into the divided nut 22, the divided portion 29 is covered with the first and second stopper pieces 32 and 33.
That is, the divided portions 34 of the first and second stopper pieces 32 and 33 are substantially orthogonal to the divided portion 29.

Therefore, the first and second stopper pieces 32 and 33 can prevent the first and second nut pieces 23 and 24 from separating from the dividing portion 29 as indicated by arrows.
Then, the force for separating the first and second nut pieces 23 and 24 is distributed to the first and second stopper pieces 32 and 33.

The force with which the first and second stopper pieces 32 and 33 are about to be separated from the dividing portion 34 as indicated by an arrow can be suppressed to a small value.
Thereby, the force which acts on the ring member 25 becomes small, and the ring member 25 can be made compact.

Next, the example which cancels | releases fastening of the 1st, 2nd to-be-fastened members 11 and 12 is demonstrated based on FIGS.
FIGS. 7A and 7B are views for explaining an example of breaking the ring member of the fastening structure according to the first embodiment.
In (a), the ring member 25 is heated by the heating means 35. The ring member 25 is extended in the circumferential direction by a split stopper 31.

  In addition, the ring member 25 is formed of a shape memory material that generates a contraction deformation force by applying heat. Therefore, by applying heat to the ring member 25, the ring member 25 is reduced in diameter and tends to contract.

Here, since the split stopper 31 is fitted in the ring member 25, the split stopper 31 prevents the ring member 25 from being reduced in diameter.
Therefore, the ring member 25 cannot be contracted and deformed. For this reason, tensile stress is generated on both sides of the fragile portion 26 of the ring member 25 as shown by arrows.

  In (b), when the tensile stress is generated in the fragile portion 26 of the ring member 25, the fragile portion 26 is broken by the generated tensile stress. While the diameter of the ring member 25 is increased, the heating means 35 is elastically deformed by being pressed by the ring member 25.

As described above, the ring member 25 is expanded in diameter, whereby the first and second stopper pieces 32 and 33 of the split stopper 31 are separated by the split portion 34 and the first and second nut pieces 23 of the split nut 22 are separated. , 24 are separated at the dividing section 29.
As a result, the split nut 22 is detached from the threaded portion 14 a of the bolt 13.
The reason why the fragile portion 26 breaks will be described in detail with reference to FIGS.

FIGS. 8A and 8B are diagrams illustrating an example of releasing the fastening state by the fastening structure according to the first embodiment.
In (a), the split nut 22 is detached from the threaded portion 14 a of the bolt 13, so that the bolt 13 falls as indicated by an arrow D.

  In (b), the clamping member 20 comes off from the bolt 13 and the fastening of the first and second fastened members 11 and 12 by the fastening structure 20 is released.

Here, conditions for self-breaking of the shape memory material will be described with reference to FIGS.
FIG. 9 is a graph showing a stress-strain curve of the shape memory material. The vertical axis shows the stress of the shape memory material, and the horizontal axis shows the strain (elongation) of the shape memory material. A curved line G1 indicated by a solid line indicates a characteristic in a heated state, and a curved line G2 indicated by a broken line indicates a characteristic in a non-heated state.

In the heated state, the first yield stress of the shape memory material is σ _r 1 and the breaking stress of the shape memory material is σ _b .
On the other hand, in the non-heated state, the first yield stress of the shape memory material is σ _r 2 and the breaking stress of the shape memory material is σ _b .
Further, in the heated state, the first yield stress is a shrinkage deformation stress.

In a non-heated state, when the shape memory material is fixed by applying a strain ε3 having a strain ε1 or more and a strain ε2 or less, an internal stress of σ _r 2 remains in the shape memory material.
If the distortion ε3 of the shape memory material is heated at a fixed state, and the shape recovery force to the shape memory material occurs, the internal stress state of the shape memory material is raised from the sigma _{r 2} to sigma _{r 1.}
Therefore, by providing the fragile portion in the shape memory material in advance, the fragile portion can be broken by the increased internal stress.
This shape memory material will be described in more detail with reference to FIG.

FIG. 10 is a diagram illustrating conditions for self-breaking of the shape memory material.
In the rod-shaped shape memory material 40, a notch 41 is formed and a fragile portion 42 is provided. The cross-sectional area of the memory member 40 and _{A w,} a cross-sectional area of the fragile portion 42 and the _{A c.} Further, the breaking load of the cross-sectional area _{A w} and _{P (A w) b,} when the breaking load in the cross-sectional area _{A c} and _{P (A c) b,}
P (A _w ) _b = σ _b · A _w
P (A _c ) _b = (σ _b · A _c ) / α
= P (A _w ) _b · R / α (1)
However, (sigma) _b : Breaking stress of the shape memory material 40 (alpha): Stress concentration factor of the weak part 42 R: _Ac / _Aw <1
It becomes.

On the other hand, when heat is applied to the shape memory material 40 in a state where both end portions 40a and 40b of the shape memory material 40 are fixed, a shrinkage deformation force is generated in the shape memory material 40, and the internal stress increases to σ _r 1.
Contraction deformation force in the cross-sectional area _{A w} and _{P (A w) r,} if the contraction deformation force in the cross-sectional area _{A c} and _{P (A c) r,}
P (A _w ) _r = σ _r 1 · A _w
P (A _c ) _r = σ _r 1 · A _c
Where σ _r 1 is the shrinkage deformation stress of the shape memory material 40.

Therefore, when applying heat to the shape memory material 40 to cause shrinkage deformation, the tensile load P (A _c ) _t acts on the fragile portion (that is, the cross-sectional area A _c ) 42.
P (A _c ) _t = P (A _w ) _r −P (A _c ) _r
= Σ _r 1 (A _w −A _c ) (2)

Using this tensile load P (A _{c) t,} when the contraction deformation force of the shape memory material 40 has occurred, in order to break at fragile portion 42, the breaking tensile load P (A _{c) t} and fragile portion The relationship with load P (A _c ) _b is
Tensile load P (A _c ) _t > Breaking load P (A _c ) _b (3)
And it is sufficient.

From Formula (1)-Formula (3),
σ _r (A _w −A _c )> P (A _w ) _b · R / α (4)
Is established.
From equation (4), the relationship between the cross-sectional area ratio R and the stress concentration factor α of the fragile portion 42 is
R <σ _r 1 · α / (σ _b + σ _r 1 · α) (5)
Is established.
That is, when the contraction deformation force is generated in the shape memory material 40, the relationship between the cross-sectional area ratio R and the stress concentration coefficient α of the fragile portion 42 satisfies the formula (5), thereby causing the fragile portion 42 to break. Can do.

Here, the relationship between the cross-sectional area ratio R and the stress concentration factor α when a Ti—Ni alloy is used as the shape memory material 40 is illustrated.
The Ti—Ni alloy has a shrinkage deformation stress σ _r 1 of 800 MPa and a breaking stress σ _b of 1300 MPa. Therefore, from equation (5)
When the stress concentration coefficient α is 1.0, by setting the cross-sectional area ratio R <0.33, the fragile portion 42 can be broken when the shape memory material 40 is restored.
Further, when the stress concentration factor α is 2.0, by setting the cross-sectional area ratio R <0.55, the fragile portion 42 can be broken when the shape memory material 40 is restored.
Furthermore, when the stress concentration factor α is 3.0, the fragile portion 42 can be broken when the shape memory material 40 is restored by setting the cross-sectional area ratio R <0.65.

Returning to FIG. 7 (a), when a shrinkage deformation force is generated in the ring member 25 in a state where the split stopper 31 is fitted in the ring member 25, both ends of the fragile portion are fixed as shown in FIG. It becomes the same as the state.
Therefore, when the ring member 25 satisfies the conditions described with reference to FIGS. 9 to 10, when the ring member 25 is heated and contraction deformation force is generated in the ring member 25, the ring member 25 is broken at the fragile portion. Can do.

As described above, according to the fastening structure 10 of the first embodiment, the shape memory material that generates contraction deformation force by applying heat (energy) to the ring member 25 that constitutes a part of the clamping member 20. Form with. Furthermore, the weak part 26 which fractures | ruptures when the shrink deformation force was generated in the ring member 25 was provided.
Thereby, the fastening of the 1st, 2nd to-be-fastened members 11 and 12 can be easily cancelled | released by applying heat to the ring member 25 and making the weak part 26 fracture | rupture.

Furthermore, by providing the ring member 25 with the fragile portion 26, the ring member 25 can be kept annular. By integrating the clamping member 20 with the annular ring member 25, the rigidity of the clamping member 20 can be increased.
As a result, the first and second fastened members 11 and 12 can be strongly held by the sandwiching member 20, and the fastening force of the first and second fastened members 11 and 12 can be sufficiently secured. Can do.

In addition, by forming the ring member 25 from a shape memory material, it is possible to apply heat to the ring member 25 to generate a contraction deformation force on the ring member 25 itself.
Thereby, since it is not necessary to provide a new member in order to generate the contraction deformation force in the ring member 25, the fastening mechanism 10 can be made compact.

  Next, second to sixth embodiments will be described with reference to FIGS. In the second to sixth embodiments, the same members as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

Second Embodiment FIG. 11 is a perspective view showing a fastening structure (second embodiment) according to the present invention, and FIG. 12 is a cross-sectional view showing the fastening structure according to the second embodiment.
The fastening structure 50 includes a clamping member (one of the clamping members provided at both ends) 51, and the other configuration is the same as that of the fastening structure 10 of the first embodiment.
The clamping member 51 is obtained by removing the division stopper 31 from the clamping member 20 (see FIG. 1) of the first embodiment, and the other configuration is the same as that of the clamping member 20 of the first embodiment.

  That is, in the fastening structure 50, the first and second nut pieces 53 and 54 are fitted into the ring member 25 and the first and second nut pieces 53 and 54 are integrated so as to be integrated. The clamping member 51 can be connected to the bolt 13.

By connecting the clamping member 51 to the bolt 13, the first and second fastened members 11, 12 are clamped and fastened by the clamping member 51 and the head portion 15 of the bolt 13.
The divided nut 52 is formed by overlapping the first and second nut pieces 53 and 54 at the dividing portion 55.

The clamping member 51 includes a split nut 52 that can be screwed to the threaded portion 14 a of the bolt 13, and includes a ring member 25 outside the split nut 52.
This clamping member 51 is provided on the threaded portion (the other of the both end portions of the rod-shaped member) 14 a of the bolt 13.

The split nut 52 has a left half portion formed of a first nut piece 53 and a right half portion formed of a second nut piece 54.
The split nut 52 has a female screw portion 52a at the center, a hexagonal portion 52b in the upper half, and a cylindrical portion 52c in the lower half.

The hexagonal portion 52b is the same as the hexagonal portion 22b of the first embodiment, and is a portion that protrudes outside the cylindrical portion 52c and is formed in a hexagonal shape.
The cylindrical portion 52c is a portion having a circular cross section formed in a tapered shape so that the outer periphery 52d is gradually reduced in diameter from the hexagonal portion 52b toward the lower end portion 52e.
By inserting the cylindrical portion 52 c into the inner periphery 27 of the ring member 25, the first and second nut pieces 53 and 54 are integrated in a state where they are overlapped by the dividing portion 55.

Next, the assembly process of the fastening structure 50 will be described.
The first and second nut pieces 53 and 54 are overlapped by the dividing portion 55, and the overlapped cylindrical portion 52 c of the divided nut 52 is placed on the ring member 25.
The cylindrical portion 52c of the split nut 52 enters the ring member 25 along the inner periphery 27 by screwing the screw portion 14a of the bolt 13 to the female screw portion 52a.

As the cylindrical portion 52c enters the inner periphery 27, the ring member 25 gradually increases in diameter. The cylindrical portion 52 c of the split nut 52 sufficiently enters the inner periphery 27 of the ring member 25, and the lower end portion 52 e of the cylindrical portion 52 c comes into contact with the first fastened member 11.
In this state, the split nut 52 is tightened by the ring member 25.

The split nut 52 is integrated, and the split nut 52 and the ring member 25 are integrated. Therefore, the clamping member 51 is integrated.
Thereby, the division | segmentation nut 52 and the clamping member 51 can be integrated easily only by fitting the cylindrical part 52c of the division | segmentation nut 52 in the ring member 25. FIG.

And it clamp | tightens by clamping the 1st, 2nd to-be-fastened members 11 and 12 with the clamping member 51 and the head 15 of the volt | bolt 13. FIG.
By integrating the split nut 52 with the ring member 25, the rigidity of the clamping member 51 can be increased.
Thereby, the 1st, 2nd to-be-fastened members 11 and 12 are clamped strongly by the clamping member 51, and the fastening force of the 1st and 2nd to-be-fastened members 11 and 12 can fully be ensured.

Further, the cylindrical member 52 c of the split nut 52 sufficiently enters the inner periphery 27 of the ring member 25, thereby expanding the diameter of the ring member 25.
By expanding the diameter of the ring member 25, the inner diameter of the upper end portion 25a becomes D2. The ring member 25 is expanded in diameter and extends in the circumferential direction.

As described above, when the first and second nut pieces 53 and 54 are integrated, that is, when the first and second members to be fastened 11 and 12 are fastened, the ring member 25 is surrounded by the split nut 52. Stretch in the direction.
Therefore, before the first and second fastened members 11 and 12 are fastened, as an example, it is not necessary to stretch the ring member 25 in the circumferential direction (so-called secondary processing) using a pulling jig. . Thereby, the assembly process can be simplified.

Next, an example of releasing the fastening of the first and second fastened members 11 and 12 will be described with reference to FIGS.
FIGS. 13A and 13B are views for explaining an example in which the ring member of the fastening structure according to the second embodiment is broken.
In (a), the ring member 25 is extended in the circumferential direction by the cylindrical portion 52 c of the split nut 52. Therefore, by applying heat to the ring member 25, the ring member 25 is reduced in diameter and tends to contract.

Here, since the cylindrical portion 52c is fitted into the ring member 25, the cylindrical member 52c prevents the ring member 25 from being reduced in diameter.
Therefore, tensile stress is generated on both sides of the fragile portion 26 of the ring member 25 as shown by arrows.

In (b), the fragile portion 26 is broken by the generated tensile stress. As the diameter of the ring member 25 is increased, the first and second nut pieces 53 and 54 of the split nut 52 are separated at the split portion 55.
As a result, the split nut 52 is detached from the threaded portion 14 a of the bolt 13.

FIGS. 14A and 14B are diagrams illustrating an example of releasing the fastening state by the fastening structure according to the second embodiment.
In (a), when the split nut 52 is detached from the threaded portion 14a of the bolt 13, the bolt 13 falls as shown by an arrow E.

  In (b), the clamping member 51 is removed from the bolt 13 and the fastening of the first and second fastened members 11 and 12 by the fastening structure 50 is released.

As described above, according to the fastening structure 50 of the second embodiment, the same effects as those of the fastening structure 10 of the first embodiment can be obtained.
In addition, according to the fastening structure 50 of the second embodiment, the configuration can be simplified by removing the split stopper 31 (see FIG. 3) used in the first embodiment.

Third Embodiment FIG. 15 is a perspective view showing a fastening structure (third embodiment) according to the present invention.
The fastening structure 60 includes a clamping member (one of the clamping members provided at both ends) 61, and the other configuration is the same as that of the fastening structure 10 of the first embodiment.

  The clamping member 61 can be connected to the bolt 13 by sandwiching and integrating the first and second nut pieces (plural divided members) 63 and 64 with rod members (connecting members) 68 and 68. 68 and 68 are formed of a shape memory material (functional material).

By connecting the clamping member 61 to the bolt 13, the first and second fastened members 11, 12 are clamped and fastened by the clamping member 61 and the head portion 15 of the bolt 13.
The split nut 62 is formed by overlapping the first and second nut pieces 63 and 64 at the split portion 65.

  In the fastening structure 60 of the third embodiment, the rod members 68 and 68 are formed of a shape memory material (functional material) that generates contraction deformation force by applying heat (energy), and is formed of this shape memory material. The rod members 68 and 68 are provided with fragile portions 68b and 68b (see FIG. 16) that can be broken when contraction deformation force is generated, and the fragile portions 68b and 68b are broken so that the first and second covered portions are broken. The fastening of the fastening members 11 and 12 can be released.

  In addition, the fastening structure 60 includes heating means 74 (... indicates a plurality) in the split nut 62, and heat is applied to the rod members 68, 68 by the heating means 74 ... to the rod members 68, 68. It is configured to generate a contraction deformation force.

FIG. 16 is an exploded perspective view showing a fastening structure according to the third embodiment.
The clamping member 61 includes a split nut 62 that can be screw-coupled to the screw portion 14 a of the bolt 13, and includes a pair of rod members 68 and 68 that clamp the split nut 62.
As shown in FIG. 15, the clamping member 61 is provided on the threaded portion (the other end of the rod-shaped member) 14 a of the bolt 13.

The split nut 62 has a left half portion formed of a first nut piece 63 and a right half portion formed of a second nut piece 64.
The split nut 62 has a female threaded portion 62a at the center and an outer wall 62b formed in a hexagonal shape, and includes a pair of engaging portions 71 and 71 facing each other in the opposing portion of the outer wall 62b.

The engaging portion 71 is provided with an engaging groove 73 that protrudes laterally from the outer wall 62 b and is orthogonal to the axis 72 of the split nut 62, and includes heating means 74 and 74 on the wall surface of the engaging groove 73.
The engagement groove 73 includes a pair of heating means 74 and 74, but the pair of heating means 74 and 74 will be collectively described as one heating means 74 for easy understanding.

The engaging groove 73 is formed in a substantially U shape, and the heating means 74 is also formed in a substantially U shape.
Both end faces 71a and 71b of the engaging portion 71 are formed substantially parallel to each other, and the distance between both end faces 71a and 71b (the distance between both end faces) is L1 (see also FIG. 15).
The engaging grooves 73 and 73 formed in the pair of engaging portions 71 and 71 are formed in parallel to each other.

The rod member 68 is a member formed of a shape memory material. The rod member 68 includes a cylindrical rod main body 68a. The rod main body 68a includes a fragile portion 68b. The rod main body 68a includes flanges 68c and 68c at both ends. Prepare each.
The fragile portion 68b is a portion whose cross-sectional area is reduced by forming a notch 69 at substantially the center of the rod body 68a.

The shape memory material for forming the rod member 68 corresponds to a shape memory alloy or a shape memory resin that generates a contraction deformation force by applying heat (energy). As an example, a Ti—Ni alloy is used.
For example, a magnetic shape memory alloy can be used as a shape memory material in place of the shape memory alloy or the shape memory resin.

The magnetic shape memory alloy is a material that generates a contraction deformation force by applying a magnetic field (energy), and an Ni—Mn—Ga alloy is used as an example.
When the rod member 68 is formed of a magnetic shape memory alloy, a magnetic field applying unit is provided instead of the heating unit 74.

In the rod member 68, the distance between the pair of flanges 68c, 68c (flange distance) is formed at L2.
The distance L1 between both end faces and the flange distance L2 satisfy the following relationship.
Distance between both end faces L1> Flange distance L2
The reason why both end face spacing L1> flange spacing L2 will be described in detail with reference to FIG.

Therefore, before engaging the rod member 68 with the engaging groove 73, for example, a pulling force is applied to the rod member 68 using a pulling jig (not shown) to increase the flange interval L2.
In this state, the rod member 68 is engaged with the engagement groove 73, the both end surfaces 71a and 71b of the engagement portion 71 are held between the pair of flanges 68c and 68c, and the first and second nut pieces 63 and 64 are sandwiched. Is integrated.

In this way, the rod member 68 is formed of a shape memory material, and the first and second nut pieces 63 and 64 are sandwiched and integrated by the rod member 68.
The rod member 68 is a small and simple rod-like member, and the cost can be reduced by applying a shape memory material to the rod member 68.

After the rod member 68 is fitted into the engagement groove 73, the seal material 76 is fitted into the engagement groove 73. By closing the opening of the engaging groove 73 with the sealing material 76, the rod member 68 is prevented from falling off, and the heat insulation of the heating means 74 and the rod member 68 is improved.
Thereby, the rod member 68 is efficiently heated by the heat generated by the heating means 74.
Note that the sealing material 76 may not be used.

Next, the assembly | attachment process of the fastening structure 60 is demonstrated based on FIGS.
FIGS. 17A to 17C are diagrams illustrating an example in which the split nuts of the fastening structure according to the third embodiment are integrated.
In (a), a tensile force is applied to the pair of rod members 68, 68 as shown by arrows using a pulling jig (not shown). The pair of rod members 68, 68 are extended so that the flange interval L2 is slightly larger than the interval L1.
Next, the first and second nut pieces 63 and 64 are overlapped by the dividing portion 65, and the rod members 68 and 68 are engaged with the left and right engaging grooves 73 and 73 as indicated by arrows F, respectively.

In (b), both end surfaces 71a and 71b of the left engagement portion 71 are sandwiched between a pair of flanges 68c and 68c, and both end surfaces 71a and 71b of the right engagement portion 71 are sandwiched between a pair of flanges 68c and 68c. To do.
Thereby, the split nut 62 including the first and second nut pieces 63 and 64 is integrated by the pair of rod members 68 and 68.
In this state, the sealing materials 76 and 76 are fitted into the left and right engaging grooves 73 and 73 as indicated by arrows G, respectively.

  In (c), the sealing materials 76 and 76 are fitted to the left and right engaging grooves 73 and 73, so that the opening portions of the left and right engaging grooves 73 and 73 are closed by the respective sealing materials 76 and 76.

FIGS. 18A and 18B are diagrams illustrating an example in which a fastened member is fastened by the fastening structure according to the third embodiment.
In (a), the threaded portion 14a of the bolt 13 is inserted from the mounting hole 12a of the second fastened member 12 as shown by the arrow H.
The inserted screw portion 14a is projected from the mounting hole 11a of the first fastened member 11 and is aligned with the female screw portion 62a.

  In this state, by rotating the bolt 13 as shown by the arrow I, the screw portion 14a is screwed to the female screw portion 62a.

In (b), the clamping member 61 and the head portion 15 of the bolt 13 are fastened by clamping the first and second fastened members 11 and 12.
By integrating the first and second nut pieces 63 and 64 with the rod members 68 and 68, the rigidity of the clamping member 61 can be increased.
As a result, the first and second fastened members 11 and 12 can be strongly held by the sandwiching member 61, and the fastening force of the first and second fastened members 11 and 12 can be sufficiently secured. Can do.

Next, the example which cancels | releases fastening of the 1st, 2nd to-be-fastened members 11 and 12 is demonstrated based on FIG.
FIGS. 19A and 19B are views for explaining an example in which the rod member of the fastening structure according to the third embodiment is broken.
In (a), the rod members 68 and 68 are heated by the heating means 74 and 74, respectively. In the extended state of the rod member 68, a pair of flanges 68c and 68c are in contact with both end faces 71a and 71b of the engaging portion 71 (see FIG. 17), respectively.
In addition, the rod member 68 is formed of a shape memory material that generates a contraction deformation force by applying heat. Therefore, by applying heat to the rod member 68, the rod member 68 tends to shrink and deform.

Here, the rod member 68 has a pair of flanges 68c and 68c that are in contact with both end faces 71a and 71b, respectively. In addition, before extending the pair of rod members 68, 68, the relationship between the distance L1 between both end faces 71a, 71b and the distance L2 between the pair of flanges 68c, 68c is L1> L2.
Therefore, the rod member 68 is prevented from contracting and deforming at both end faces 71a and 71b.
For this reason, tensile stress is generated on both sides of the fragile portion 68b of the rod member 68 as shown by arrows.

In (b), when the tensile stress is generated in the fragile portion 68b of the rod member 68, the fragile portion 68b is broken by the generated tensile stress.
When the fragile portion 68 b of the rod member 68 is broken, the first and second nut pieces 63 and 64 of the split nut 62 are separated by the split portion 65.

As a result, the split nut 62 is detached from the threaded portion 14 a of the bolt 13.
When the split nut 62 is detached from the threaded portion 14a of the bolt 13, the clamping member 61 is detached from the bolt 13, and the fastening of the first and second fastened members 11 and 12 by the fastening structure 60 is released.

  As described above, according to the fastening structure 60 of the third embodiment, the same effect as that of the fastening structure 10 of the first embodiment can be obtained.

  In the third embodiment, both end surfaces 71a, 71b of the engaging portion 71 are formed substantially parallel to each other, and before the pair of rod members 68, 68 are assembled to the split nut 62, the pair of rod members 68, Although the example of extending 68 in advance has been described, when the pair of rod members 68, 68 are assembled to the split nut 62 by using both end faces 71a, 71b as tapered surfaces, the pair of rod members 68, 68 are simultaneously extended. It is also possible to configure it.

Fourth Embodiment FIG. 20 is a perspective view showing a fastening structure (fourth embodiment) according to the present invention, and FIG. 21 is a cross-sectional view showing the fastening structure according to the fourth embodiment.
The fastening structure 80 is configured such that a bolt (rod-like member) 81 is inserted into the mounting hole 11a of the first fastened member 11 and the mounting hole 12a of the second fastened member 12, and an upper nut is attached to the bolt 81 protruding upward from the mounting hole 11a. (One clamping member) 82 is screw-coupled, and a lower nut (the other clamping member) 83 is screw-coupled to a bolt 81 projecting downward from the mounting hole 12a. 2 to-be-fastened members 11 and 12 are clamped and fastened.

  In the fastening structure 80, the bolt 81 is formed of a shape memory material (functional material) that generates a contraction deformation force when heat (energy) is applied, and the bolt 81 formed of the shape memory material has a contraction deformation force. When the fragile portion 85 is generated, the fragile portion 85 that can be broken is provided, and by breaking the fragile portion 85, the fastening of the first and second fastened members 11 and 12 can be released.

  Furthermore, the fastening structure 80 includes a heating unit 91 inside the bolt 81, and heat is applied to the bolt 81 by the heating unit 91 to generate a contraction deformation force on the bolt 81.

  The bolt 81 is formed in a cylindrical body with a shape memory material, has a weakened portion 85 in the approximate center, has an upper screw portion 86 at an upper end portion (one of both end portions) 81a, and a lower end portion (the other end of both end portions) 81b. A lower screw portion 87 is provided, and a hollow portion 88 is provided on the axis of the bolt 81.

The fragile portion 85 is a portion having a reduced cross-sectional area by forming a notch 89 at substantially the center of the bolt 81.
The notch 89 is illustrated as having a V-shaped cross section, but is not limited thereto, and can be formed in a U-shaped cross section.
The hollow portion 88 is a through hole that opens to the upper end portion 81a and the lower end portion 81b.

The shape memory material for forming the bolt 81 corresponds to a shape memory alloy or a shape memory resin that generates a contraction deformation force when heat (energy) is applied. As an example, a Ti—Ni alloy is used.
For example, a magnetic shape memory alloy can be used as a shape memory material in place of the shape memory alloy or the shape memory resin.

The magnetic shape memory alloy is a material that generates a contraction deformation force by applying a magnetic field (energy), and an Ni—Mn—Ga alloy is used as an example.
When the bolt 81 is formed of a magnetic shape memory alloy, a magnetic field applying unit is provided instead of the heating unit 91.

The upper nut 82 is provided on the upper end portion 81 a of the bolt 81 by screwing to the upper screw portion 86 of the bolt 81.
The lower nut 83 is provided at the lower end portion 81 b of the bolt 81 by being screwed to the lower screw portion 87 of the bolt 81.

The upper nut 82 is screwed to the upper threaded portion 86 and the lower nut 83 is screwed to the lower threaded portion 87, whereby the upper and lower nuts 82 and 83 hold the first and second fastened members 11 and 12 together. To do.
By sandwiching the first and second fastened members 11 and 12 with the upper and lower nuts 82 and 83, the upper and lower ends 81a and 81b of the bolt 81 are pulled.
Accordingly, when the first and second fastened members 11 and 12 are clamped and fastened by the upper and lower nuts 82 and 83, a tensile force is applied to the bolt 81.

Note that one of the upper and lower nuts 82 and 83 can be the head of the bolt 81. By using one of the upper and lower nuts 82 and 83 as the head of the bolt 81, the number of parts can be reduced.
On the other hand, the amount of the shape memory material used can be suppressed by using the upper and lower nuts 82 and 83 as in the fourth embodiment.

A heating means 91 is provided in the hollow portion 88 of the bolt 81.
The heating means 91 is a wire heater that can be inserted into the hollow portion 88.
The heating means 91 is connected to a battery (not shown) by wire harnesses 92 and 92, for example. The heater is heated by keeping the heating means 91 in an energized state, and the bolt 81 is heated by the heat generated from the heater.

  By inserting the heating means 91 into the hollow portion 88, it is embedded in the center of the bolt 81. As a result, the heat generated from the heating means 91 can be efficiently transmitted to the bolt 81, and the bolt 81 can be heated uniformly.

Next, an example in which the bolt 81 of the fastening structure 80 is broken and the fastening of the first and second fastened members 11 and 12 is released will be described with reference to FIG.
FIGS. 22A and 22B are views for explaining an example of breaking the bolt of the fastening structure according to the fourth embodiment.
First, the process of fastening the first and second fastened members 11 and 12 will be described.
In (a), the bolt 81 is inserted into the mounting hole 11a of the first fastened member 11 and the mounting hole 12a of the second fastened member 12, and the upper end portion 81a protrudes from the mounting hole 11a and the lower end from the mounting hole 12a. The part 81b protrudes.

The upper nut 82 is screwed to the upper threaded portion 86 of the upper end portion 81a as indicated by arrow J, and the lower nut 83 is screwed to the lower threaded portion 87 of the lower end portion 81b as indicated by arrow K.
The first and second fastened members 11 and 12 are sandwiched and fastened by the upper and lower nuts 82 and 83.
By sandwiching the first and second fastened members 11 and 12 with the upper and lower nuts 82 and 83, the upper and lower ends 81a and 81b are pulled.
A tensile force is applied to the bolt 81, and the bolt 81 is maintained in an extended state.

Therefore, when the first and second members to be fastened 11 and 12 are fastened, it is not necessary to apply a tensile force to the bolt 81 in advance to extend (so-called secondary processing).
Thereby, it is possible to omit the step of applying a tensile force to the bolt 81 in advance when fastening.

Next, an example in which the bolt 81 is broken will be described.
In a state where the first and second fastened members 11 and 12 are fastened, the bolt 81 is heated by the heating means 91.
The bolt 81 is kept in an extended state. In addition, the bolt 81 is formed of a shape memory material that generates a shrinkage deformation force by applying heat.
Therefore, by applying heat to the bolt 81, the bolt 81 tends to shrink and deform.

Here, the upper and lower ends 81a and 81b of the bolt 81 are supported by upper and lower nuts 82 and 83, respectively.
Therefore, the bolt 81 is prevented from contracting and a tensile stress is generated on both sides of the fragile portion 85 of the bolt 81 as shown by arrows.

In (b), when the tensile stress is generated in the fragile portion 85 of the bolt 81, the fragile portion 85 is broken by the generated tensile stress.
When the fragile portion 85 is broken, the clamping of the first and second fastened members 11 and 12 by the upper and lower nuts 82 and 83 is released, and the first and second fastened members 11 and 12 by the fastening structure 80 are released. Release the conclusion of.

  As described above, according to the fastening structure 80 of the fourth embodiment, the same effects as those of the fastening structure 10 of the first embodiment can be obtained.

Fifth Embodiment FIG. 23 is a perspective view showing a fastening structure (fifth embodiment) according to the present invention, and FIG. 24 is an exploded perspective view showing a fastening structure according to a fifth embodiment.
The fastening structure 100 includes a wedge-shaped clamping member (one clamping member) 101 instead of the upper nut 82 of the fourth embodiment, and the other structure is the same as the fastening structure 80 of the fourth embodiment. It is the same.

  That is, in the fastening structure 100, a bolt (rod-like member) 102 is inserted into the mounting hole 11a of the first fastened member 11 and the mounting hole 12a of the second fastened member 12, and the bolt 102 protruding downward from the mounting hole 12a is used. The lower nut 83 is screw-coupled, and a wedge-shaped clamping member 101 is provided on the bolt 102 protruding upward from the mounting hole 11a, whereby the first and second fastened members 11, the lower nut 83 and the wedge-shaped clamping member 101, 12 is clamped and fastened.

  In this fastening structure 100, the bolt 102 is formed of a shape memory material (functional material) that generates a contraction deformation force by applying heat (energy), and the bolt 102 formed of the shape memory material has a contraction deformation force. The fragile portion 103 that can be broken at the time of occurrence is provided, and by breaking the fragile portion 103, the fastening of the first and second fastened members 11 and 12 can be released.

  Further, the fastening structure 100 includes a heating unit 91 inside the bolt 102, and heat is applied to the bolt 102 by the heating unit 91 to generate a contraction deformation force on the bolt 102.

The bolt 102 is formed of a shape memory material into a cylindrical body, has an engagement hole 105 formed at the upper end (one of both ends) 102a, has a weakened portion 103 on both sides of the engagement hole 105, and has a lower end (both ends). A lower screw part 87 is provided on the other part 102 b and a hollow part 106 is provided on the axis of the bolt 102.
The hollow portion 106 is provided with heating means 91.

The engagement hole 105 is a substantially rectangular hole that is formed perpendicular to the axis of the bolt 102 and has both ends opened to the peripheral wall.
The fragile portion 103 is a portion whose cross-sectional area is reduced by forming the engagement hole 105 in the upper end portion 102 a of the bolt 102.
The hollow portion 106 is a through hole (see FIG. 25) opened to the engagement hole 105 and the lower end portion 102b.

The shape memory material for forming the bolt 102 corresponds to a shape memory alloy or a shape memory resin that generates a shrinkage deformation force by applying heat (energy), and a Ti—Ni alloy is used as an example.
For example, a magnetic shape memory alloy can be used as a shape memory material in place of the shape memory alloy or the shape memory resin.

The magnetic shape memory alloy is a material that generates a contraction deformation force by applying a magnetic field (energy), and an Ni—Mn—Ga alloy is used as an example.
When the bolt 102 is formed of a magnetic shape memory alloy, a magnetic field applying unit is provided instead of the heating unit 91.

The wedge-shaped holding member 101 is formed such that the insertion portion 108 can be inserted into the engagement hole 105, and a head portion 109 is provided at the proximal end of the insertion portion 108. The insertion portion 108 includes a tapered portion 108a at the tip.
The taper portion 108a is a tapered portion in which the upper surface 108b is formed in a downward slope gradually toward the tip in a side view.
By inserting the insertion portion 108 of the clamping member 101 into the engagement hole 105, the clamping member 101 is provided on the upper end portion 102 a of the bolt 102.

The lower nut 83 is screwed to the lower screw portion 87, and the wedge-shaped holding member 101 is inserted into the engagement hole 105, whereby the lower nut 83 and the wedge-shaped holding member 101 are connected to the first and second fastened members 11, 12 is pinched.
By holding the first and second fastened members 11 and 12 with the lower nut 83 and the wedge-shaped holding member 101, the upper and lower ends 102a and 102b of the bolt 102 are pulled.
Accordingly, when the first and second fastened members 11 and 12 are clamped and fastened by the lower nut 83 and the wedge-shaped clamping member 101, a tensile force is applied to the bolt 102.

Next, an example in which the bolt 102 of the fastening structure 100 is broken to release the fastening of the first and second fastened members 11 and 12 will be described with reference to FIGS.
FIGS. 25A and 25B are views for explaining an example in which a fastened member is fastened by the fastening structure according to the fifth embodiment.
In (a), the bolt 102 is inserted into the mounting hole 11a of the first fastened member 11 and the mounting hole 12a of the second fastened member 12, and the lower nut 83 is screwed to the lower threaded portion 87 of the lower end 102b.

The insertion part 108 of the clamping member 101 is inserted into the engagement hole 105 of the bolt 102 as shown by an arrow L.
The upper surface 108b of the tapered portion 108a contacts the ceiling surface 105a of the engagement hole 105. In this state, the insertion portion 108 is continuously inserted as shown by the arrow L, so that the upper surface 108b pushes the ceiling surface 105a upward.

In (b), the clamping member 101 is provided on the upper end 102 a of the bolt 102 by bringing the head 109 of the clamping member 101 into contact with the peripheral wall of the bolt 102.
The first and second fastened members 11 and 12 are clamped by the lower nut 83 and the clamping member 101.

Here, when the clamping member 101 is inserted into the engagement hole 105, the upper end portion 102a of the bolt 102 is pulled upward by pushing the ceiling surface 105a of the engagement hole 105 upward by the upper surface 108b of the taper portion 108a. .
A tensile stress is applied to the bolt 102, and the bolt 102 is maintained in an extended state.

Therefore, when the first and second members to be fastened 11 and 12 are fastened, it is not necessary to apply a tensile force to the bolt 102 in advance to extend (so-called secondary processing).
Thereby, when fastening, it is possible to omit a step of applying a tensile force to the bolt 102 in advance.

Next, an example in which the bolt 102 is broken will be described.
In the state where the first and second members to be fastened 11 and 12 are fastened, the bolt 102 is heated by the heating means 91.
The bolt 102 is kept in an extended state. In addition, the bolt 102 is formed of a shape memory material that generates a contraction deformation force by applying heat.
Therefore, by applying heat to the bolt 102, the bolt 102 tends to shrink and deform.

The bolt 102 has an upper end portion 102 a supported by the clamping member 101 and a lower end portion 102 b supported by the lower nut 83.
Therefore, the bolt 102 is prevented from contracting and a tensile stress is generated on both sides of the weakened portion 103 (see also FIG. 24) of the bolt 102 as indicated by arrows.

FIG. 26 is a diagram for explaining an example in which the bolt of the fastening structure according to the fifth embodiment is broken.
When tensile stress is generated in the fragile portion 103 of the bolt 102, the fragile portion 103 is broken by the generated tensile stress.
When the fragile portion 103 is broken, the clamping of the first and second fastened members 11 and 12 by the clamping member 101 and the lower nut 83 is released, and the first and second fastened members 11 and 12 by the fastening structure 100 are released. 12 is released.

  As described above, according to the fastening structure 100 of the fifth embodiment, the same effects as those of the fastening structure 80 of the fourth embodiment can be obtained.

Sixth Embodiment FIG. 27 is a perspective view showing a fastening structure (sixth embodiment) according to the present invention, and FIG. 28 is an exploded perspective view showing a fastening structure according to the sixth embodiment.
In the fastening structure 120, a rivet (rod-like member) 121 is inserted into the attachment hole 11a of the first member to be fastened 11 and the attachment hole 12a of the second member to be fastened 12, and the head portion (one clamping member) 124 of the rivet 121 is inserted. It forms in a flange shape, the 1st to-be-fastened member 11 is pressed with the head 124, the enlarged diameter part (other clamping member) 125 of the rivet 121 is formed with the mandrel 126, and the second to-be-fastened member is formed with the enlarged diameter part 125. By pressing 12, the first and second fastened members 11, 12 are sandwiched and fastened by the head portion 124 and the enlarged diameter portion 125.
The rivet 121 is a blind rivet.

  In the fastening structure 120, the rivet 121 is formed of a shape memory material (functional material) that generates a contraction deformation force by applying heat (energy), and the contraction deformation force is applied to the rivet 121 formed of the shape memory material. The fragile portion 127 that can be broken when the first and second members to be fastened 11 and 12 can be released by breaking the fragile portion 127.

  Further, the fastening structure 120 includes a heating unit 131 inside the rivet 121, and heat is applied to the rivet 121 by the heating unit 131 so that a contraction deformation force is generated in the rivet 121.

  The rivet 121 is a member formed of a shape memory material and includes a rivet body 123 formed in a cylindrical shape, and a head portion 124 formed in a flange shape at the upper end (one of both ends) of the rivet body 123. The main body 123 is provided with an enlarged diameter portion 125 that is enlarged by a mandrel 126 at the lower end portion (the other end of both ends), a fragile portion 127 is provided substantially at the center of the rivet main body 123, and a hollow portion 128 is provided on the axis of the rivet 121. .

The fragile portion 127 is a portion having a reduced cross-sectional area by forming a notch 129 at substantially the center of the rivet body 123.
The notch 129 is illustrated as having a V-shaped cross section, but is not limited thereto, and can be formed in a U-shaped cross section.
The hollow portion 128 is a hole that opens in the head portion 124 and has a communication hole formed in the bottom portion. The hollow portion 128 faces the mandrel 126 through the communication hole 133.

As the shape memory material for forming the rivet 121, a shape memory alloy and a shape memory resin that generate shrinkage deformation force by applying heat (energy) are applicable. As an example, a Ti—Ni alloy is used.
For example, a magnetic shape memory alloy can be used as a shape memory material in place of the shape memory alloy or the shape memory resin.

The magnetic shape memory alloy is a material that generates a contraction deformation force by applying a magnetic field (energy), and an Ni—Mn—Ga alloy is used as an example.
When the rivet 121 is formed of a magnetic shape memory alloy, a magnetic field applying unit is provided instead of the heating unit 131.

A heating means 131 is provided in the hollow portion 128 of the rivet 121.
The heating means 131 has a cylindrical body that can be inserted into the hollow portion 128, and a heater is built in the cylindrical body.
The heating means 131 is connected to a battery (not shown) by wire harnesses 132 and 132, for example. The heater is heated by keeping the heating means 131 energized, and the rivet 121 is heated by the heat generated from the heater.

  By inserting the heating means 131 into the hollow portion 128, the heating means 131 is embedded in the center of the rivet 121. Thereby, the heat generated from the heating means 131 can be efficiently transmitted to the rivet 121 and the rivet 121 can be heated uniformly.

Next, the example which fastens the 1st, 2nd to-be-fastened members 11 and 12 with the fastening structure 120 is demonstrated based on FIGS.
FIGS. 29A and 29B are views for explaining an example in which a rivet having a fastening structure according to the sixth embodiment is set on a member to be fastened.
In (a), the rivet material 135 is inserted through the mounting hole 11a of the first fastened member 11 and the mounting hole 12a of the second fastened member 12, and the head 124 is brought into contact with the first fastened member 11.

The rivet material 135 has a hollow portion 128, a communication hole 133, and a storage space 136. A tension member 137 is passed through the hollow portion 128, the communication hole 133, and the storage space 136, an upper end portion 137 a of the tension member 137 projects upward from the hollow portion 128, and a mandrel 126 is connected to the lower end portion 137 b of the tension member 137. ing.
An upper end portion 126 a of the mandrel 126 enters the storage space 136.

  The riveter nosepiece 141 and the riveter chuck 142 are lowered as indicated by an arrow M. The rivetta nose piece 141 is inserted into the space 144 between the hollow portion 128 and the tension member 137, and the rivetta chuck 142 is fitted into the upper end portion 137 a of the tension member 137.

In (b), the step portion 145 of the rivet material 135 is pressed as indicated by an arrow N by the tip portion 141 a of the rivetta nose piece 141.
Here, since the head portion 124 of the rivet material 135 is in contact with the first fastened member 11, the rivet body 123 is pulled downward as indicated by an arrow O.
A tensile stress is applied to the rivet body 123, and the rivet body 123 is maintained in an expanded state.
In this state, the riveter chuck 142 holds the upper end 137a of the tension member 137.

FIGS. 30A to 30C are diagrams illustrating an example in which a fastened member is fastened by the fastening structure according to the sixth embodiment.
In (a), the riveter chuck 142 is raised as shown by an arrow P, and the upper end portion 137a of the tension member 137 is pulled upward by the riveter chuck 142.
The mandrel 126 enters the storage space 136 (see FIG. 29), and the upper end portion 126a of the mandrel 126 contacts the stepped portion 145.

The lower end portion 135a (see FIG. 29) of the rivet material 135 is pushed and widened by the mandrel 126 to form the enlarged diameter portion 125.
As a result, the rivet material 135 (see FIG. 29) becomes the rivet 121, and the first and second fastened members 11 and 12 are clamped and fastened by the head portion 124 and the enlarged diameter portion 125.

In this state, the rivet body 123 is pulled downward as indicated by an arrow O and is maintained in an expanded state.
Therefore, when the first and second members to be fastened 11 and 12 are fastened, it is not necessary to apply a tensile force to the rivet 121 in advance to extend (so-called secondary processing).
Thereby, it is possible to omit a step of applying a tensile force to the rivet 121 in advance when fastening.

In (b), the riveter chuck 142 is continuously raised as shown by the arrow P, whereby the lower end portion 137b of the tension member 137 is broken from the upper end portion 126a of the mandrel 126. The tension member 137 is separated from the mandrel 126.
The riveter nose piece 141 and the rivetta chuck 142 are raised as indicated by the arrow Q, and the riveter nose piece 141 is taken out of the space 144.

In (c), the heating means 131 is attached to the hollow portion 128 of the rivet 121 as shown by the arrow R.
Thereby, the process of fastening the 1st, 2nd to-be-fastened members 11 and 12 with the fastening structure 120 is completed.

Next, an example of breaking the rivet 121 of the fastening structure 120 and releasing the fastening of the first and second fastened members 11 and 12 will be described based on FIG.
FIGS. 31A and 31B are views for explaining an example of breaking a rivet of the fastening structure according to the sixth embodiment.
In (a), the rivet 121 is heated by the heating means 131 in a state where the first and second fastened members 11 and 12 are fastened by the rivet 121.
The rivet body 123 of the rivet 121 is maintained in an extended state. In addition, the rivet 121 is formed of a shape memory material that generates a contraction deformation force by applying heat.
Therefore, by applying heat to the rivet 121, the rivet 121 tends to shrink and deform.

The rivet 121 has an upper end supported by the head 124 and a lower end supported by the enlarged diameter portion 125.
Therefore, the rivet body 123 of the rivet 121 is prevented from contracting and deforming, and tensile stress is generated on both sides of the fragile portion 127 of the rivet body 123 as indicated by arrows.

In (b), when the tensile stress is generated in the fragile portion 127 of the rivet body 123, the fragile portion 127 is broken by the generated tensile stress.
When the fragile portion 127 is broken, the clamping of the first and second fastened members 11 and 12 by the head portion 124 and the enlarged diameter portion 125 is released, and the first and second fastened members 11 by the fastening structure 120 are released. , 12 is released.

  As described above, according to the fastening structure 120 of the sixth embodiment, the same effect as that of the fastening structure 10 of the first embodiment can be obtained.

Here, the use of the fastening structures 10, 50, 60, 80, 100, 120 of the first to sixth embodiments will be described.
The fastening structures 10, 50, 60, 80, 100, and 120 are applied to “seat”, “around the door”, “seat belt”, “steering”, and the like in an assembly such as an automobile.

The application location to the “seat” includes a location where the seat cushion is attached to the seat rail, a location where the reclining is attached to the seat cushion, and a location where the seat rail is attached to the floor.
The application location to “around the door” includes a location where the door striker is attached to the vehicle body, a location where the door hinge is attached to the vehicle body, and a location where the door checker is attached.

As an application place to the “seat belt”, there is a place where the anchor is attached to the vehicle body.
The application location for “steering” includes the location where the steering wheel is attached to the steering shaft.

As described above, it is difficult to secure a sufficient space in the installation space for the “seat”, “around the door”, “seat belt” and “steering”.
For this reason, it can attach easily by using the fastening structure 10, 50, 60, 80, 100, 120 which can be compactized.

  In addition, although the said 1st-6th embodiment demonstrated the example which fastened the 2 member of the 1st, 2nd to-be-fastened members 11 and 12 as several to-be-fastened members, it does not restrict to this. For example, a member to be fastened such as three members can be fastened.

  In the first and second embodiments, two nut pieces (first and second nut pieces) are exemplified as the plurality of divided members. However, the present invention is not limited to this. It is also possible to constitute a divided member such as a member.

Furthermore, in the first to sixth embodiments, the examples in which the fastening means 10, 50, 60, 80, 100, 120 are provided with the heating means 35, 74, 91, 131 have been described, but the present invention is not limited thereto. Thus, it is not necessary to provide the heating means in the fastening structure.
In this case, separate heating means are prepared separately from the fastening structure, and the fastening state of the fastening structure is released by the individual heating means.

  Moreover, although the said 1st-6th embodiment demonstrated the example which applied fastening structure 10,50,60,80,100,120 to the assembly of a motor vehicle, it is not restricted to this, Others It is also possible to apply to an assembly.

Furthermore, in the said 1st-6th embodiment, although shape memory material was illustrated as a functional material, it is not restricted to this, A functional element can also be used.
Examples of the functional element include a magnetostrictive element, a piezoelectric (electrostrictive) element, and an optical strain element.
The magnetostrictive element is a material that generates a contraction deformation force by applying a magnetic field (energy), and Tafenol-D or Gafenol-D is used as an example.
A piezoelectric (electrostrictive) element is a material that generates contraction deformation force by application of voltage (energy). As an example, PZT (lead zirconate titanate) is used.
The photostrictive element is a material that generates shrinkage deformation force by irradiation of light (energy), and PLZT (lead lanthanum zirconate titanate) is used as an example.

Here, the shape memory material used in the first to sixth embodiments is a material that generates contraction deformation force by restoring energy that has been previously expanded by applying energy. Therefore, it is necessary to incorporate the shape memory material into the fastening structure in a stretched state.
On the other hand, a magnetostrictive element, a piezoelectric (electrostrictive) element, and a photostrictive element are materials that generate contraction deformation force by applying energy.

Therefore, by using a magnetostrictive element, a piezoelectric (electrostrictive) element, or a photostrictive element, it is not necessary to incorporate these elements into the fastening structure in an extended state. That is, it is possible to incorporate these elements into the fastening structure without extending them.
This facilitates the work of incorporating the magnetostrictive element, piezoelectric (electrostrictive) element, and photostrictive element into the fastening structure.

When a magnetostrictive element is used, magnetic field applying means for applying a magnetic field to the magnetostrictive element is incorporated in the fastening structure or prepared separately from the fastening structure.
Further, when a piezoelectric (electrostrictive) element is used, a voltage applying means for applying a voltage to the piezoelectric (electrostrictive) element is incorporated in the fastening structure or prepared separately from the fastening structure. .
Further, when the photostrictive element is used, the light irradiating means for irradiating the photostrictive element with light is incorporated into the fastening structure or prepared separately from the fastening structure.

  The present invention is suitable for application to a fastening structure in which a rod-like member is inserted through a plurality of members to be fastened, and the fastened members are fastened by clamping members provided at both ends of the rod-like member.

It is a perspective view which shows the fastening structure (1st Embodiment) which concerns on this invention. It is sectional drawing which shows the fastening structure which concerns on 1st Embodiment. It is a disassembled perspective view which shows the fastening structure which concerns on 1st Embodiment. It is a figure explaining the example which sets the division | segmentation nut of the fastening structure which concerns on 1st Embodiment to a to-be-fastened member. It is a figure explaining the example which carries out the screw connection of the volt | bolt to the division | segmentation nut of the fastening structure which concerns on 1st Embodiment. It is a figure explaining the example which fastened the member to be fastened with the fastening structure concerning a 1st embodiment. It is a figure explaining the example which fractures | ruptures the ring member of the fastening structure which concerns on 1st Embodiment. It is a figure explaining the example which cancels | releases the fastening state by the fastening structure which concerns on 1st Embodiment. It is a graph which shows the stress-strain curve of shape memory material. It is a figure explaining the conditions of the self-rupture of a shape memory material. It is a perspective view which shows the fastening structure (2nd Embodiment) which concerns on this invention. It is sectional drawing which shows the fastening structure which concerns on 2nd Embodiment. It is a figure explaining the example which fractures | ruptures the ring member of the fastening structure which concerns on 2nd Embodiment. It is a figure explaining the example which cancels | releases the fastening state by the fastening structure which concerns on 2nd Embodiment. It is a perspective view which shows the fastening structure (3rd Embodiment) which concerns on this invention. It is a disassembled perspective view which shows the fastening structure which concerns on 3rd Embodiment. It is a figure explaining the example which integrates the division | segmentation nut of the fastening structure which concerns on 3rd Embodiment. It is a figure explaining the example which fastened the to-be-fastened member with the fastening structure which concerns on 3rd Embodiment. It is a figure explaining the example which fractures | ruptures the rod member of the fastening structure which concerns on 3rd Embodiment. It is a perspective view which shows the fastening structure (4th Embodiment) which concerns on this invention. It is sectional drawing which shows the fastening structure which concerns on 4th Embodiment. It is a figure explaining the example which fractures | ruptures the bolt of the fastening structure which concerns on 4th Embodiment. It is a perspective view which shows the fastening structure (5th Embodiment) which concerns on this invention. It is a disassembled perspective view which shows the fastening structure which concerns on 5th Embodiment. It is a figure explaining the example which fastened the to-be-fastened member with the fastening structure which concerns on 5th Embodiment. It is a figure explaining the example which fractures | ruptures the bolt of the fastening structure which concerns on 5th Embodiment. It is a perspective view which shows the fastening structure (6th Embodiment) which concerns on this invention. It is a disassembled perspective view which shows the fastening structure which concerns on 6th Embodiment. It is a figure explaining the example which sets the rivet of the fastening structure which concerns on 6th Embodiment to a to-be-fastened member. It is a figure explaining the example which fastens a to-be-fastened member with the fastening structure which concerns on 6th Embodiment. It is a figure explaining the example which fractures | ruptures the rivet of the fastening structure which concerns on 6th Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10,50,60,80,100,120 ... Fastening structure, 11 ... 1st to-be-fastened member (fastened member), 12 ... 2nd to-be-fastened member (fastened member), 13 ... Bolt (bar-shaped member), 14a ... Screw part of bolt (the other of both ends of the rod-shaped member), 14b ... Base end of the rod part (one of both ends of the rod-shaped member), 15 ... Head of the bolt (the other of the clamping members provided at both ends) ), 20, 51, 61... Clamping members (one clamping member among the clamping members provided at both ends), 22, 52, 62... Split nuts, 23, 53, 63. One of a plurality of divided members), 24, 54, 64 ... second nut piece (the other of the plurality of divided members), 25 ... Ring member (connecting member), 26, 68b, 85, 103, 127 ... Fragile portion, 35 74, 91, 131 ... heating means, 68 ... rod member (connection) Material), 68c ... flange, 81, 102 ... bolt (rod-like member), 81a ... upper end of the bolt (one of both ends), 81b ... lower end of the bolt (the other of both ends), 82 ... upper nut (one Clamping member), 83 ... lower nut (the other clamping member), 101 ... wedge-shaped clamping member (one clamping member), 121 ... rivet (bar-shaped member), 123 ... rivet body, 124 ... rivet head (one Clamping member), 125... Diameter-enlarged portion of the rivet (the other clamping member).

Claims (4)

A fastening structure in which a rod-shaped member is inserted through a plurality of members to be fastened and fastened by sandwiching the members to be fastened with sandwiching members provided at both ends of the rod-shaped member,
Of the members constituting the rod-shaped member and the sandwiching member, at least one member is formed of a functional material that generates contraction deformation force by applying energy,
In the member formed of this functional member, provided with a fragile portion that breaks when a contraction deformation force is generated by the energy,
A fastening structure characterized in that the fastening of the fastened member can be released by breaking the fragile portion. A fastening structure in which a rod-shaped member is inserted through a plurality of members to be fastened and fastened by sandwiching the members to be fastened with sandwiching members provided at both ends of the rod-shaped member,
Among the clamping members provided at both ends of the rod-shaped member, at least one clamping member can be connected to the rod-shaped member by integrating a plurality of divided members with a coupling member,
This connecting member is formed of a functional material that generates contraction deformation force by applying energy,
In the member formed of this functional member, provided with a fragile portion that breaks when a contraction deformation force is generated by the energy,
A fastening structure characterized in that the fastening of the fastened member can be released by breaking the fragile portion. A fastening structure in which a rod-shaped member is inserted through a plurality of members to be fastened and fastened by sandwiching the members to be fastened with sandwiching members provided at both ends of the rod-shaped member,
The rod-shaped member is formed of a functional material that generates shrinkage deformation force by applying energy,
In the member formed of this functional member, provided with a fragile portion that breaks when a contraction deformation force is generated by the energy,
A fastening structure characterized in that the fastening of the fastened member can be released by breaking the fragile portion. The functional material is a shape memory material,
The fastening structure according to claim 1, wherein the at least one member is a member formed so that a tensile force can be applied when the fastened member is fastened.

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