JP6148877B2 - Connecting structure using restraints - Google Patents

Description

The present invention relates to a connection structure using fastening bolts, nuts, and restraints in various wooden structures.

  In various wooden structures such as wooden construction, there is a method of simply using a nail or an adhesive to connect the members, but in order to connect members such as columns and beams, which are the skeleton of wooden construction, Shape brackets and bolts are often used. Bolts have the advantage of being able to absorb the energy by plastic deformation when subjected to an excessive tensile load in an earthquake, thereby reducing damage to the building. However, after the bolt is plastically deformed, the connection of the members is loosened and it is difficult to absorb energy again. In order to solve this point, a technique has been proposed that can absorb energy stably even after plastic deformation by eliminating the looseness of the bolt as in the following patent document.

  Patent Document 1 discloses a fastener that can maintain the strength of a fastening portion even after bolts are plastically deformed. In FIG. 1 of this document, in order to install the column on the foundation, a box-shaped metal fitting is sandwiched between the foundation and the column, and a long fastening bolt is inserted from the metal fitting toward the column. Further, a pressing tool for restraining the head of the fastening bolt is incorporated so that the fastening bolt does not loosen even after the fastening bolt is plastically deformed. In FIG. 7 of this document, a pair of metal fittings is used to connect the pillar and the beam in an L shape, and the fastening bolts are concentrically opposed to fix each metal fitting to the pillar or the beam. It is out. Opposing heads are intentionally brought into contact with each other so that the fastening bolts are not loosened.

  Patent Document 2 discloses a connector that can maintain a certain degree of strength even after a bolt is plastically deformed. In this document, in consideration of aesthetics, the entire connector is embedded in a bar, and for connecting the bars, a stud bolt with a right-hand thread formed at one end and a left-hand thread formed at the other end Is used. And the edge part of a stud bolt is screwing together with internal screws, such as an embedding tool embedded in each member. Therefore, even after the stud bolt is plastically deformed, it is possible to minimize the looseness of the connected bar.

  FIG. 10 shows a specific example of a connection structure in which end surfaces of two members are brought into close contact with each other to be unified. In this figure, a total of two sets of lag screws are screwed so that they are concentrically opposed with the contact surface of both members as a base point, and two lag screws arranged concentrically are integrated with a fastening bolt and a nut. The lag screw is in the shape of a metal round bar, and is firmly integrated with the member by a ridge protruding from the side peripheral surface. The fastening bolt is a stud bolt without a head. In addition, a cutout portion is provided on the side surface of the member in order to expose end portions of the lag screw and the fastening bolt. At the time of construction, the end of the fastening bolt is protruded into the cutout, and a washer and nut are assembled there.

JP 2011-247029 A JP 2012-77545 A

  In the structure in which members are connected using bolts as in the above-mentioned patent document, various technical developments have been advanced so that the rigidity of the connecting portions can be maintained even after the bolts are subjected to a tensile load and plastically deformed. However, as shown in FIG. 10, in the structure in which a cutout portion in which the side surface of the member is locally cut out is provided and the nut is screwed into the fastening bolt protruding therein, even after the fastening bolt is plastically deformed, No measures have yet been established to maintain the rigidity of the connecting part.

The present invention has been developed based on such circumstances, and a fastening bolt is inserted into the member, and a cutout portion is provided on the side surface of the member to expose the end of the fastening bolt, and the fastening bolt is plastically deformed. after you, about the connecting structure using the restraint it has a function of maintaining the rigidity of the connecting portion.

The invention according to claim 1 for solving the above-mentioned problem is characterized in that a fastening bolt is inserted into a member, and a cutout portion for exposing an end of the fastening bolt is provided on a side surface of the member, A connection structure using a restraining tool fitted into the cutout part, and a plurality of nuts screwed in parallel with the end part of the fastening bolt exposed at the cutout part, the end part of the fastening bolt, and the cutout part A restraint that fits between the inner surface of the fastening bolt, the nut positioned inward of the fastening bolt bears the connection between the members, and the restraint is positioned near the end of the fastening bolt. A fastening surface including a pressing surface that contacts the nut, a protrusion that protrudes from the pressing surface and enters the center of the nut, and an outward surface that faces the pressing surface and contacts the inner surface of the cutout portion. The nut located near the end of The by close contact with the pressing surface, a connecting structure using the restraint, characterized in that to regulate the displacement of the end portion of the fastening bolt.

  The present invention is used for installation of members constituting a skeleton of a wooden building, such as columns and beams, and can be introduced not only in connection between members but also in connection between members and column base hardware. However, the method of connecting the members is limited to a form in which the fastening bolts inserted inside are brought into close contact with each other, and the shaft end portion of the fastening bolt is assumed to be exposed to a cutout portion processed on the side surface of the member. To do.

  The fastening bolt may be a hexagon bolt having a head at one end or a hexagon socket head bolt, or a stud bolt composed only of a shaft portion. Then, if a hole is machined so as to penetrate the members to be connected, a fastening bolt is inserted therein, and a nut is screwed into the shaft end portion to tighten it, a tensile load acts on the fastening bolt, and the members Is in close contact. In addition, in order to prevent the torsion etc. of the member after a connection, several fastening bolts are inserted about one member.

  The cutout portion is a missing portion where the side surface of the member is locally cut out, and has a role of exposing the shaft end portion of the fastening bolt inserted into the member to the outside. Since the shaft end portion of the fastening bolt is exposed, a nut can be screwed there. In order to prevent the member from being cracked by a tightened nut or the like, the cutout portion is arranged slightly apart from the connection surface between the members.

  The cutout portion is a weak point in the strength of the member, so it should be made as small as possible, but care must be taken so as not to affect the tightening operation of the nut. In addition, the cutout portion can be opened to the outside as a hole shape whose inner surface is completely closed or a groove shape extending in a direction orthogonal to the axial direction of the fastening bolt.

The restraint tool is incorporated in the cutout portion, and is fitted between the nut screwed into the fastening bolt and the inner surface of the cutout portion, and plays a role of preventing the nut from moving in the axial direction of the fastening bolt. . Therefore, a restraint tool is provided with the press surface which contacts a nut, and the outward surface which contacts the inner surface of a cutout part. In addition, a press surface contacts the surface far from the connection surface of members among the both end surfaces of the clamp | tightened nut. Moreover, an outward surface is arrange | positioned so as to oppose a press surface, and contacts the inner surface of a cutout part. In addition, a plurality of nuts are used in one cutout portion, and a part thereof is tightened toward the connecting surface between the members, while the rest is tightened on the opposite side and closely attached to the pressing surface.

  By incorporating a restraint in the cutout portion, the nut cannot move in a direction away from the connecting surface between the members. Therefore, the shaft end portion of the fastening bolt is maintained in the construction state, and the protruding length to the cutout portion does not increase.

The shape of the restraint tool is determined each time according to the size of the cutout portion, the arrangement of the nut, and the like, but the details may be freely determined as long as the movement of the nut can be restricted. However, in order to improve workability during construction, a protrusion is formed on the pressing surface. This protrusion enters the center of the nut, thereby stabilizing the posture of the restraining tool.

Thus, the protruding shaft end portion of the fastening bolt into the cutout portion, the connecting structure in which there is screwed a nut, a restraint fitted between the inner surface of the end portion and the cutout portion of the fastening bolt By using, the axial end part and nut of a fastening bolt can regulate the displacement in a cutout part. Therefore, even after an excessive tensile load acts on the connecting portion and the fastening bolt is plastically deformed, the nut does not float in the cutout portion, and the connection of the members does not loosen.

As in the first aspect of the present invention, the protruding shaft end portion of the fastening bolt into the cutout portion, the connecting structure in which there is screwed a nut, between the inner surface of the end portion and the cutout portion of the fastening bolt By using the restraining tool that fits into the shaft, the shaft end portion and the nut of the fastening bolt can regulate displacement in the cutout portion. Therefore, even after an excessive tensile load acts on the connecting part and the fastening bolt is plastically deformed, the nut does not float in the cutout part, and the fastening bolt can be prevented from loosening. It is transmitted to the fastening bolt as it is.

Therefore, even in the connection structure as shown in FIG. 10, by introducing the present invention, the same effect as the prior art document can be obtained. When this connection structure encounters a large-scale earthquake, the elastic-plastic deformation of the fastening bolt is repeated without interruption until the shaking converges, so a great deal of energy is absorbed and the safety of buildings, etc. Can be increased.

It is a perspective view which shows the example of the shape of the restraint tool by this invention, and the connection structure of the members incorporating this, and a restraint tool is cylindrical shape. It is the perspective view of the state which connected the one material and other material of FIG. 1, and its AA sectional drawing. It is sectional drawing which shows the condition where the tensile load acted on one material and the other material of FIG. 2, and the cut surface is the same as the AA cross section of FIG. Although it is a perspective view which shows the connection structure similar to FIG. 1, the restraint tool of a hook-and-loop shape is used. The cross-sectional view of FIG. 4 shows the procedure for incorporating the restraint. It is a perspective view which shows the case where one material and the other material are connected using the restraint tool which has a bottom receiving surface. It is the perspective view of the state which connected the one material and other material of FIG. 6, and its BB sectional drawing. It is a perspective view which shows the form which used two sets of restraints for the cutout part of one place. The cross-sectional view of FIG. 8 shows the procedure for incorporating the restraint. It is a perspective view of the connection structure which shows an example of a prior art and makes the end surfaces of two members closely_contact | adhere.

  FIG. 1 shows an example of the shape of a restraint 11 according to the present invention and a connecting structure of members incorporating the same. In this figure, it is assumed that the end surfaces of two rod-shaped members are brought into close contact with each other, and for convenience, the upper member is referred to as one member 41 and the lower member is referred to as the other member 51. The cross-sectional shapes of the one material 41 and the other material 51 are the same, and both are made of wood containing laminated material and constitute the building skeleton. And the connection of the one material 41 and the other material 51 bears two fastening bolts. The fastening bolt is a stud bolt 36 having male screws formed at both ends, and is inserted so as to penetrate the boundary between the one material 41 and the other material 51.

  In order to receive the compressive load acting on the boundary between the one material 41 and the other material 51, two lag screws 31 are screwed into the end surfaces of the respective members. The lag screw 31 is in the shape of a metal round bar. On the side circumferential surface thereof, a spirally extending ridge 32 protrudes, and on one end surface, a hexagonal portion 34 for hanging a tool is formed. . Further, in the center, in order to insert the stud bolt 36, an inner hole 33 penetrating both ends is formed. And in order to screw in the lag screw 31 in any one material 41 and the other material 51, the lower holes 45 and 55 are processed so that it may oppose from an end surface. The lag screw 31 is firmly integrated with the member because the entire area of the ridge 32 bites into the member.

  In both the one material 41 and the other material 51, circular cutout portions 43 and 53 are processed at a position somewhat away from the end face. The cutouts 43 and 53 are literally cut out of the side surfaces of the member with a drill, have a bottom, and intersect the lower holes 45 and 55 in the middle. Therefore, the tip of the screwed lag screw 31 enters the cutout portions 43 and 53. The four lag screws 31 have the same shape, and the two stud bolts 36 have the same shape.

  At the time of construction, first, all the lag screws 31 are screwed into the one material 41 and the other material 51, and then the stud bolt 36 is inserted into the inner hole 33 on the upper surface of the other material 51. Thereafter, the end surfaces of the one material 41 and the other material 51 are brought close to each other, the stud bolt 36 is inserted into the inner hole 33 on the one material 41 side, and the one material 41 and the other material 51 are brought into contact with each other. Are exposed to the cutout portions 43 and 53. When the washer 35 is assembled there, and then the nut 37 is screwed and tightened, the concentric lag screws 31 are integrated via the stud bolt 36, and the one member 41 and the other member 51 are connected.

  The restraint 11 is a metal column and is sized so as to fit into the cutouts 43 and 53. In order to avoid interference with the stud bolt 36, nut 37, and washer 35, the cross section is "convex". Cut out in a letter shape. A pressing surface 21 extending in a strip shape is formed on the left and right at substantially the center of the restraint 11. The pressing surface 21 is in contact with the far side from the boundary between the one material 41 and the other material 51 among the both end surfaces of the nut 37. Therefore, loosening of the nut 37 can be prevented, and movement of the nut 37 in a direction away from the boundary between the one material 41 and the other material 51 can be restricted. In addition, a range of the outer peripheral surface of the restraining tool 11 that is in contact with the inner surfaces of the cutout portions 43 and 53 and that transmits a load that pushes the pressing surface 21 is referred to as an outward surface 23. The outward surface 23 necessarily faces the pressing surface 21.

  The restraint tool 11 needs to contact the end face of the tightened nut 37, and the shape is determined according to the length of the lag screw 31, the arrangement of the cutout portions 43 and 53 and the lower holes 45 and 55, and the like. In consideration of aesthetics, one end surface of the restraint tool 11 is closed with an end lid 22. Therefore, when the restraining tool 11 is fitted into the cutout portions 43 and 53, the end lid 22 is aligned with the side surfaces of the one material 41 and the other material 51 without any step. The four restraints 11 in the figure have the same shape, but the posture differs depending on the place of use.

  FIG. 2 shows a state in which one material 41 and the other material 51 of FIG. 1 are connected. The one material 41 and the other material 51 are drawn through the stud bolt 36 and are in close contact with each other. The lag screw 31 and the stud bolt 36 are completely embedded in the one material 41 and the other material 51. In addition, the restraining tool 11 is fitted into the cutout portions 43 and 53, and only the end lid 22 is exposed to the outside. In addition, the restraint tool 11 is hold | maintained at the cutout parts 43 and 53 by friction, and does not come out naturally.

  Further, as shown in the A-A cross-sectional view, the upper and lower lag screws 31 arranged concentrically are in contact with each other, and bear the transmission of the compressive load in the vertical direction. Therefore, the stress acting on the boundary between the one material 41 and the other material 51 is relieved, and the depression or biting of the one material 41 or the other material 51 can be prevented in this vicinity.

  The ridges 32 of the lag screw 31 bite into the one material 41 and the other material 51, and the lag screw 31 is completely integrated therewith. Furthermore, the tip of the lag screw 31 (the end surface away from the boundary between the one material 41 and the other material 51) reaches the cutout portions 43 and 53. The stud bolt 36 passes through the upper and lower lag screws 31, and both end portions thereof protrude from the lag screw 31 and are exposed to the cutout portions 43 and 53.

  A washer 35 is incorporated at the end of the stud bolt 36 protruding from the lag screw 31, and a nut 37 is screwed on the outside thereof. The restraint 11 is fitted in the cutouts 43 and 53, and the entire outer peripheral surface of the restraint 11 including the outward face 23 is in contact with the inner surfaces of the cutouts 43 and 53, and the outward face 23. The opposing pressing surface 21 is in contact with the end surface of the nut 37. Therefore, the movement of the nut 37 is completely restricted, and the stud bolt 36 is not loosened. The cross section of the restraint 11 is cut out in a “convex” shape, and the stud bolt 36 is accommodated in the center thereof, and the nut 37 and the washer 35 are accommodated in the widened portion. .

  FIG. 3 is a cross-sectional view showing a state in which a tensile load is applied to the one material 41 and the other material 51 of FIG. In addition, a cut surface is the same as the AA cross section of FIG. The tensile load that separates the one material 41 and the other material 51 is transmitted from the lag screw 31 to the stud bolt 36 via the nut 37. At this time, if the stress acting on the stud bolt 36 is within a certain range, no gap is generated at the boundary between the one material 41 and the other material 51. However, when an excessive load is applied due to an earthquake or the like, the stud bolt 36 is plastically deformed as shown on the left side of FIG. 3, and a gap is generated between the one material 41 and the other material 51.

  Even when such a gap is generated, the nut 37 is pressed by the restraint 11 and does not float from the lag screw 31, and the stud bolt 36 is not loosened. Therefore, even after a gap is generated between the one material 41 and the other material 51, both the materials are integrated via the stud bolt 36, and a decrease in rigidity of the connecting portion can be suppressed. When the direction of the load further changes and the one material 41 and the other material 51 come into contact again, the stud bolt 36 is compressed by the pressing surface 21 and the nut 37 as shown on the right side of FIG. Deforms to meander. As a result, the connection between the one material 41 and the other material 51 is maintained in the same state as the original.

  When actually encountering a large-scale earthquake, the stud bolt 36 is repeatedly expanded and compressed as shown in FIG. Therefore, the stud bolt 36 can continuously absorb energy until the earthquake converges, and the safety of the building and the like is improved.

  In FIG. 4, as in FIG. 1, the one material 41 and the other material 51 are connected by the stud bolt 36, but the restraining tool 12 is formed in a scallop shape. Two lug screws 31 are screwed into each of the one material 41 and the other material 51, a stud bolt 36 is inserted into the inner hole 33, and a nut 37 is screwed onto the stud bolt 36 exposed at the cutout portions 43 and 53. This is the same as in FIG. However, it is assumed that the restraining tool 12 fills the gap between the end surface of the stud bolt 36 and the inner surfaces of the cutout portions 43 and 53. Therefore, the restraining tool 12 is shaped like a cone corresponding to the inner surfaces of the cutout portions 43 and 53, and the curved surface contacting the cutout portions 43 and 53 becomes the outward surface 23, and the plane facing this becomes the pressing surface 21.

  Two nuts 37 and 38 are used for one cutout portion 43 and 53. Among them, the nut 37 located inside contacts the end surface of the lag screw 31 and bears the connection between the one material 41 and the other material 51. On the other hand, the nut 38 located outside contacts the restraint tool 12 and restricts the movement of the stud bolt 36.

  Since the restraint tool 12 fills the gap between the end surface of the stud bolt 36 and the inner surfaces of the cut-out portions 43 and 53, the thickness of the restraint device 12 is limited. As in the restraint tool 11 of FIG. It cannot be closed. A cylindrical protrusion 24 is formed at the center of the pressing surface 21. The protrusion 24 is intended to improve workability when the outer nut 38 is tightened, and the protrusion 24 enters the nut 38 to stabilize the posture of the restraining tool 12 and prevent an unexpected drop or the like. .

  FIG. 5 is a drawing of the cross section of FIG. 4 and shows the procedure for incorporating the restraint 12. In addition, this figure makes the center of lag screw 31 grade | etc., As a cut surface similarly to the AA cross section of FIG. First, as shown in the upper left figure, the stud bolt 36 is inserted so as to pass through the concentric lag screws 31, the washer 35 is assembled at the end, and the nut 37 is screwed together, so that the one material 41 and the other material 51 are connected. Next, as shown in the upper right figure, a new nut 38 is screwed onto the end of the stud bolt 36. The nut 38 continues to be screwed in until the tip of the stud bolt 36 is exposed.

  Further, as shown in the lower left figure, the restraint 12 is inserted into the boundary between the end surface of the stud bolt 36 and the inner surfaces of the cutout portions 43 and 53, and the protrusion 24 is aligned with the stud bolt 36. Finally, as shown in the lower right figure, the nut 38 near the end of the stud bolt 36 is rotated and brought into contact with the pressing surface 21 of the restraining tool 12. Thereafter, the nut 38 cannot move in a direction away from the boundary between the one material 41 and the other material 51, and even when the stud bolt 36 is plastically deformed by a tensile load, the stud bolt 36 is not loosened.

  FIG. 6 shows a case where the one member 41 and the other member 51 are connected using the restraining tool 13 having the bottom receiving surface 25, and is the same as FIG. 1 except for the internal shape of the restraining tool 13. In addition to the pressing surface 21 that contacts the end surface of the nut 37, the restraining tool 13 is formed with an elongated strip-shaped bottom receiving surface 25 on the left and right sides so as to face the pressing surface 21. The bottom receiving surface 25 contacts the washer 35 to prevent the nut 37 from sinking. A range of the outer peripheral surface of the restraining tool 13 that faces the bottom receiving surface 25 is an inward surface 26. As described above, by providing the bottom receiving surface 25 and the inward surface 26, the restraining tool 13 is also involved in transmission of a tensile load acting on the one material 41 and the other material 51. The role of the pressing surface 21 is exactly the same as in FIG.

  FIG. 7 shows a state in which one material 41 and the other material 51 of FIG. 6 are connected. As in the BB cross section, the outer edge of the washer 35 is in contact with the bottom receiving surface 25 of the restraining tool 13. Therefore, the tensile load acting on the one material 41 and the other material 51 is transmitted from the one material 41 or the other material 51 to the restraining tool 13 via the inward surface 26, and further from the bottom receiving surface 25 via the washer 35 and the nut 37. This is transmitted to the stud bolt 36.

  In this way, by providing the bottom receiving surface 25 and the inward surface 26 on the restraint 13, the transmission path of the tensile load is not limited to the lag screw 31 and diversifies, so that it acts on the one material 41 and the other material 51. Stress is relieved and safety is further improved. In this figure, the connection of the one material 41 and the other material 51 can be maintained with only the stud bolt 36, the nut 37, the washer 35, and the restraining tool 13. Therefore, even when the lag screw 31 cannot exhibit its original function for some reason, a certain degree of strength can be secured.

  In addition, the lag screw 31 depicted in the drawings so far can be replaced with a deformed steel bar. When a deformed steel bar is actually used, a center hole for inserting the stud bolt 36 is formed at the center thereof. The deformed steel bar is fixed to the lower holes 45 and 55 of the member with an adhesive.

  FIG. 8 shows a form in which two sets of restraining tools 12 and 14 are used in one cutout portion 43 and 53. In this figure, the one member 41 and the other member 51 are connected only by the stud bolt 36 without using the lag screw 31, and is constituted by the crown body 16 and the plate body 17 in order to realize transmission of the tensile load. A restraint 14 is used. The plate body 17 is shaped like a paddle, and the curved surface portion is an inward surface 26 that contacts the inner surfaces of the cutout portions 43 and 53. When the plate body 17 is incorporated into the cutout portions 43 and 53, the inward surface 26 is directed toward the boundary between the one material 41 and the other material 51. The crown body 16 has a role of contacting and pressing the plate body 17 and is cylindrical, but one end thereof is closed, and this end surface becomes a bottom receiving surface 25 that contacts the nut 37. Further, a hole for inserting the stud bolt 36 is provided in the center of the bottom receiving surface 25.

  When the crown body 16 and the plate body 17 are brought into contact with each other, the bottom receiving surface 25 and the inward surface 26 face each other and can transmit a load. In addition to the restraining tool 14 constituted by the crown body 16 and the plate body 17, the restraining tool 12 is also incorporated into the end face of the stud bolt 36. The restraint 12 is exactly the same as that in FIG. 4, and restricts the movement of the end of the stud bolt 36 by contacting the nut 38.

  FIG. 9 depicts the cross section of FIG. 8 and shows the procedure for incorporating the restrainers 12, 14. In addition, this figure makes the center of the stud bolt 36 etc. into a cut surface similarly to the AA cross section of FIG. First, as shown in the upper left figure, the stud bolt 36 is inserted so as to penetrate the one member 41 and the other member 51. Next, as shown in the upper right figure, when the restraint 14 composed of the crown body 16 and the plate body 17 is inserted into the stud bolt 36 and further tightened by screwing the nut 37, the one material 41 and the other material 51 are connected. Is completed. Thereafter, the tensile load acting on the one member 41 and the other member 51 is transmitted to the stud bolt 36 via the nut 37 through the inward surface 26 of the plate member 17 and the bottom receiving surface 25 of the crown member 16.

  Further, as shown in the lower left figure, a new nut 38 is screwed into the stud bolt 36, and the restraining tool 12 is inserted into the boundary between the end face of the stud bolt 36 and the inner surfaces of the cutout portions 43, 53, and the protrusion 24 is inserted into the stud bolt. Align with 36. Finally, as shown in the lower right figure, the nut 38 near the end of the stud bolt 36 is rotated and brought into contact with the pressing surface 21 of the restraining tool 12. Thereafter, the nut 38 cannot move in a direction away from the boundary between the one material 41 and the other material 51.

11 Restraint (cylindrical with pressing surface)
12 Restraint (Kamaboko shape)
13 Restraint (cylindrical with pressing surface and bottom receiving surface)
14 Restraint (composed of crown and plate)
16 Crown body 17 Plate body 21 Press surface 22 End cover 23 Outward surface 24 Projection 25 Bottom receiving surface 26 Inward surface 28 Shaft hole 31 Lug screw 32 Rib 33 Medium hole 34 Hex portion 35 Washer 36 Stud bolt (fastening bolt)
37 Nut 38 Nut (outside)
41 One material (member)
43 Cutout 45 Lower hole 46 Small hole 51 Other material (member)
53 Cutout 55 Pilot hole 56

Claims (1)

The fastening bolts (36) are inserted into the members (41, 51), and the cut-out portions (43, 53) for exposing the ends of the fastening bolts (36) on the side surfaces of the members (41, 51). ), And a connecting structure using a restraining tool (12) fitted into the cutout part (43, 53),
A plurality of nuts (37, 38) screwed in line with the end portions of the fastening bolts (36) exposed in the cutout portions (43, 53);
A restraining tool (12) fitted between an end of the fastening bolt (36) and an inner surface of the cutout (43, 53);
Use
The nut (37) located inward of the fastening bolt (36) bears the connection between the members (41, 51),
The restraining tool (12) has a pressing surface (21) that contacts the nut (38) located near the end of the fastening bolt (36), and protrudes from the pressing surface (21) and the nut (38). A protrusion (24) that enters the center of the outer surface, an outward surface (23) that faces the pressing surface (21) and contacts the inner surface of the cutouts (43, 53),
With
The nut (38) located near the end of the fastening bolt (36) is closely attached to the pressing surface (21), thereby restricting displacement of the end of the fastening bolt (36). A connecting structure using the restraining tool (12).

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