JP2009191968A - Bolt temporary fixing nut - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent corotation of a bolt when fastening a nut properly and to restrain rusting of a bolt thread part. <P>SOLUTION: One end face in an axis direction of a cylindrical part 15 larger in diameter than a bolt hole 3 of a bottom steel plate 1 is provided with a thin-walled ring-like protrusion 13 projected in the axis direction as a low rigidity part 11 to form a bolt temporary fixing nut 9. The bolt temporary fixing nut 9 is screwed from one axis direction end side to a thread part 5a of a high tension bolt 5 inserted into the bolt hole 3 of the bottom steel plate 1 from below, and the bolt temporary fixing nut 9 is tightened until the ring-like protrusion 13 is pressed to the bottom steel plate 1 and deformed to be crushed in the axis direction. The one axis direction end of the bolt temporary fixing nut 9 is thereby brought into close contact with the peripheral edge part of the bolt hole 3 of the bottom steel plate 1 by the restoring force of the deformed ring-like protrusion 13, and the bolt 5 is temporarily fixed into the bolt hole 3 by fastening axial force to the bolt temporary fixing nut 9 prevented from corotation by frictional force generated to a close contact part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bolt temporary fixing nut used to temporarily fix a bolt used for fastening an overlapping portion between steel plates to a bolt hole of a required steel plate in advance.

  In recent years, as a floor slab for constituting a bridge, the formwork forming the lower surface of the concrete layer of the floor slab is used as a panel-shaped bottom steel plate, and concrete is directly placed inside the bottom steel plate, thereby Synthetic floor slabs of the type in which steel plates and concrete layers are joined together have come to be used.

  In order to construct this type of composite floor slab, first, after arranging the bottom steel plates in the radial direction on the main girder, it is necessary to connect the adjacent bottom steel plates.

  When connecting the adjacent bottom steel plates, normally, as shown in FIG. 5, the bottom steel plates are arranged in a state where the adjoining plates 2 are arranged on the upper side of the butt ends of the adjacent bottom steel plates 1. Bolts (high-strength bolts) 5 are inserted from the lower surface side of the bottom steel plate 1 into the bolt holes 3 and 4 drilled in the overlapping portion of 1 and the attachment plate 2. After that, the washer 7 is fitted to the tip of the bolt 5 protruding above the attachment plate 2 and then the nut 6 is screwed and tightened so that each of the bottoms as the overlapping portion of the steel plates is secured. The overlapping portions of the steel plate 1 and the splicing plate 2 are joined by bolts 5 so that the butt ends of the adjacent bottom steel plates 1 are connected to each other by friction joining via the splicing plate 2. It is.

  When the overlapping portion of the bottom steel plate 1 and the attachment plate 2 is joined using the bolt 5 as described above, the bolt 5 inserted through the bolt holes 3 and 4 from the lower surface side of the bottom steel plate 1 is dropped. It was necessary to screw and tighten the nut 6 from the upper side of the attachment plate 2 while being held so as not to fall.

  Therefore, as a technique for eliminating the work from the lower surface side of the bottom steel plate at the construction site of the bottom steel plate 1 of the composite floor slab, a bolt previously inserted from below into the bolt hole 3 of the bottom steel plate 1 It has been considered that 5 is held in the bolt hole 3 portion through a required jig so as not to fall off.

  6A, 6B and 6C show a conventionally proposed hook ring 8 as an example of a jig for holding the bolt 5 in the bolt hole 3 of the bottom steel plate 1 so as not to fall off. .

  The hook ring 8 has a slightly larger outer diameter than the bolt hole 3 formed in the bottom steel plate 1 and has a length dimension (height dimension) in the axial direction of the attachment plate 2. A female screw portion (not shown) for screwing onto the screw portion (shaft portion) 5a of the bolt 5 is provided on the inner peripheral surface of a ring-shaped member having a dimension smaller than the plate thickness. As a result, as shown in FIG. 6 (a), after the bolts 5 are respectively inserted from below into the bolt holes 3 provided at the butt end portions of the adjacent bottom steel plates 1, the screw portions 5a of the respective bolts 5 are inserted into the screw portions 5a. The hook ring 8 is fitted by screw connection from above, and the hook ring 8 is applied around the bolt hole 3 of each bottom steel plate 1 so that the bolt 5 in the bottom steel plate 1 is bolted in advance. Can be held in a state in which the fall is prevented.

  Therefore, thereafter, as shown in FIG. 6 (b), an attachment plate formed by drilling a bolt hole 4 large enough to allow the hook ring 8 to pass above the butt end of each bottom steel plate 1. 2 is placed from above so that the bolt 5 held in the bolt hole 3 of each bottom steel plate 1 is inserted through the bolt hole 4 and then the bolt 5 as shown in FIG. In addition, by fitting the nut 6 from above through the washer 7 and tightening from above the attachment plate 2, the joining operation of the attachment plate 2 to each bottom steel plate 1, that is, the above-described operation via the attachment plate 2 is performed. The connection work of the bottom steel plates 1 can be performed only from the top side of the bottom steel plate 1 (see, for example, Patent Document 1).

  By the way, as a rust prevention treatment on the lower surface side of the bottom steel plate 1 which is the back surface of the composite floor slab as shown in FIG. 5, zinc spraying was originally considered, but recently, on the lower surface side of the bottom steel plate 1. In many cases, the entire surface is painted.

  Therefore, in order to make it unnecessary to perform the painting work from the lower surface side of the bottom steel plate 1 at the construction site of the bottom steel plate 1, the applicant assigns a bolt to the bolt hole 3 of the bottom steel plate 1 in a factory or the like. It is considered that the preliminary coating is performed over the entire lower surface of the bottom steel plate 1 including the heads of the bolts 5 with the 5 inserted and held.

JP 2004-176909 A

  However, the hook ring 8 shown in the above-mentioned patent document 1 is fitted into the screw portion 5a of the bolt 5 inserted through the bolt hole 3 of the bottom steel plate 1 from below by screw coupling, and the lower end surface thereof is fitted to the bottom steel plate 1. The hook ring 8 has a peripheral wall with a constant wall thickness over the entire length in the axial direction, and the axial center over the entire length in the axial direction. Since the rigidity in the direction is uniform, the lower end portion of the hook ring 8 is in contact with the upper surface of the bottom steel plate 1 even if it is screwed into the screw portion 5a of the bolt 5 and screwed in. Then, since it cannot be screwed any further at that time, the degree of adhesion of the hook ring 8 to the peripheral edge of the bolt hole 3 on the upper surface of the bottom steel plate 1 cannot be increased so much. There is a problem that it is difficult to increase the frictional force between the ring 8. Therefore, when the nut 5 for joining the attachment plate 2 is screwed and tightened to the bolt 5 held in the bolt hole 3 of the bottom steel plate 1 via the hook ring 8, The reality is that there is a concern about the possibility of turning around.

  Therefore, even if the bolt 5 is held in the bolt hole 3 of the bottom steel plate 1 in the factory or the like with the hook ring 8 being prevented from falling off, the nut 6 is tightened on the bolt 5. If the rotation of the bolt 5 occurs at this time, the coating film may be cracked or peeled off, so that it precedes the entire lower surface of the bottom steel plate 1 including the head of the bolt 5. It was difficult to paint.

  Furthermore, vibrations during transportation of the bottom steel plate 1 and the like due to the fact that the closeness of the lower end surface of the hook ring 8 to the periphery of the upper end portion of the bolt hole 3 on the upper surface of the bottom steel plate 1 cannot be increased so much. There is also a concern that the hook ring 8 is easily loosened. Further, since the degree of adhesion between the hook ring 8 and the peripheral edge of the bolt hole 3 of the bottom steel plate 1 with which the hook ring 8 contacts is low and airtight, the hook ring 8 is inserted into the bolt hole 3 of the bottom steel plate 1. In the state where the bolt 5 is held by using a bolt, if there is a period until the construction of the bottom steel plate 1, it is positioned inside the bolt hole 3 of the bottom steel plate 1 in the threaded portion 5 a of the bolt 5 due to moisture intrusion or the like. There is also a concern that rust may be generated in the part to be done.

  Therefore, the present invention can temporarily fix the bolt used for joining the overlapping portions of the steel plates to the bolt hole of a required steel plate through which the bolt is first inserted, and the above-mentioned required when temporarily fixing the bolt. The degree of adhesion with the peripheral edge of the bolt hole of the steel plate can be increased, and the frictional force between the required steel plates can be increased, thereby joining the overlapping portions of the steel plates. It is possible to prevent the possibility of co-rotation of the bolt even when the nut is finally tightened to the bolt, and the head of the bolt used for joining the overlapping portions of the steel plates is connected to the bolt. It is an object of the present invention to provide a bolt fixing nut that can be pre-painted together with the steel plate surface around the head.

  In order to solve the above-described problem, the present invention corresponds to claim 1 and includes a predetermined steel plate that is inserted into an overlapping portion of a plurality of steel plates and screwed to a bolt for joining the plurality of steel plates. In the bolt temporary fixing nut for temporarily fixing the bolt to the bolt hole of the predetermined steel plate, the bolt has a diameter larger than the bolt hole of the predetermined steel plate and is disposed on one end side in the axial direction of the cylindrical portion that contacts the predetermined steel plate. A low-rigidity portion is provided so that the rigidity of the low-rigidity portion in the axial direction is smaller than the rigidity of other portions in the axial direction of the cylindrical portion.

  Further, the low-rigidity portion in the above-described configuration is formed by a thin ring-shaped projection provided so as to project a required dimension in the axial direction from one axial end surface of the cylindrical portion.

  Similarly, the configuration in which the low-rigidity portion in the above configuration is formed by providing a groove extending in the circumferential direction on the outer peripheral surface or inner peripheral surface of the cylindrical portion or one axial end surface of the cylindrical portion. To do.

  Similarly, the rigid portion in the above configuration is configured to be formed by providing a stepped portion with a small wall thickness on the outer peripheral surface or inner peripheral surface of one end portion in the axial direction of the cylindrical portion.

According to the bolt temporary fixing nut of the present invention, the following excellent effects are exhibited.
(1) A bolt temporary fixing nut that allows the bolt to be temporarily fixed to a bolt hole of a predetermined steel plate by being inserted into an overlapping portion of the plurality of steel plates and screwed to a bolt for joining the plurality of steel plates. In this case, a low-rigidity portion is provided on one end side in the axial direction of the cylindrical portion that is larger in diameter than the bolt hole of the predetermined steel plate and contacts the predetermined steel plate, and the axial direction of the low-rigidity portion is Since the rigidity is configured to be smaller than the rigidity of the other portion in the axial direction of the cylindrical portion, the bolt threaded portion inserted from one side into the bolt hole of the predetermined steel plate The bolt temporary fixing nut is screwed from one end in the axial direction, and is screwed in until the low rigidity portion of the bolt temporary fixing nut is in contact with the other side surface of the predetermined steel plate. The rigid part is crushed in the axial direction When tightened until it is deformed, the restoring force of the low-rigidity part deformed so as to be crushed in the axial direction causes one end in the axial direction of the low-rigidity part of the bolt temporary fixing nut to It can be made to adhere to the peripheral part of the bolt hole on the other side. As a result, the large frictional force generated in the closely contacted portion prevents the bolt temporary fixing nut from co-rotating with the bolt. Therefore, the bolt can be temporarily fixed to the bolt hole of the predetermined steel plate in a state where rotation is prevented by the tightening axial force against the bolt temporary fixing nut.
(2) Further, the bolt rigid fixing nut and the bolt hole on the other side surface of the predetermined steel plate are brought into close contact with the peripheral portion of the bolt hole on the other side surface of the predetermined steel plate It is possible to seal between the peripheral portions of the two. Therefore, in the state where the bolt is temporarily fixed to the bolt hole of the predetermined steel plate using the bolt temporary fixing nut, it is possible to suppress the intrusion of moisture into the bolt hole of the predetermined steel plate. It is possible to suppress a possibility that rust is generated in a portion located inside the bolt hole of the predetermined steel plate in the portion.
(3) A configuration in which the low-rigidity portion is formed by a thin ring-shaped protrusion provided so as to project a required dimension in the axial direction from one axial end surface of the cylindrical portion, or the low-rigidity portion, A configuration that is formed by providing a groove extending in the circumferential direction on the outer peripheral surface or inner peripheral surface or one axial end surface of the cylindrical portion in the axial direction, or the low-rigidity portion of the cylindrical portion. By adopting a configuration in which a step portion having a small thickness of the peripheral wall is provided on the outer peripheral surface or inner peripheral surface of one end portion in the axial direction, the cylindrical portion as shown in (1) above is formed. A bolt temporary fixing nut having a low rigidity portion on one end side in the axial direction can be easily realized.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  1 (a), (b), (c) and FIG. 2 show the bottom of a composite floor slab similar to that shown in FIG. 5 as an example of an overlapped portion of steel plates as an embodiment of a bolt temporary fixing nut of the present invention. The case where the high strength bolt 5 used for joining the overlapping portion of the steel plate 1 and the splicing plate 2 is temporarily fixed to the bolt hole 3 of the bottom steel plate 1 is shown as follows.

  That is, the bolt temporary fixing nut 9 of the present invention has an outer diameter dimension larger than that of the bolt hole 3 provided in the bottom steel plate 1 as the predetermined steel plate shown in FIG. A cylindrical portion 10 having a required dimension extending in the direction and having an internal thread portion 12 for being screwed to the threaded portion 5a of the bolt 5 on the inner peripheral surface, and one axial end side of the cylindrical portion 10 In addition, a configuration in which the low-rigidity portion 11 is integrally provided so that the rigidity in the axial direction of the low-rigidity portion 11 is smaller than the rigidity of other portions in the axial direction of the cylindrical portion 10. And

  More specifically, the low-rigidity portion 11 has a lower axial rigidity than that of the cylindrical portion 10 by making the thickness of the peripheral wall smaller than that of the cylindrical portion 10. To make it smaller. More specifically, for example, a ring-shaped protrusion 13 that is thinner than the cylindrical portion 10 is formed at an intermediate portion in the radial direction (circumferential wall thickness direction) on one axial end surface of the cylindrical portion 10. The ring-shaped protrusion 13 is provided so as to project the required dimension in the axial direction, and the low-rigidity portion 11 having a lower axial rigidity than the cylindrical portion 10 is formed.

  Further, the bolt temporary fixing nut 9 is made of a soft metal such as copper, brass, aluminum or the like, more preferably a synthetic resin, so as to allow a required elastic deformation. Thereby, the bolt temporary fixing nut 9 is inserted into the bolt hole 3 of the bottom steel plate 1 from below through the washer 7 from the one end side in the axial direction where the low rigidity portion 11 is provided. By screwing and tightening, the ring-shaped protrusion 13 that becomes the low-rigidity portion 11 of the bolt temporary fixing nut 9 due to the tightening axial force of the bolt temporary fixing nut 9 and the high-strength bolt 5 is formed on the bottom steel plate 1. The ring-shaped protrusion 13 is elastically deformed so as to be crushed in the axial direction by being pressed against the peripheral edge of the bolt hole 3 on the upper surface of the bolt. Thus, the protruding end portion (one end portion in the axial center direction) of the ring-shaped protrusion 13 as the low-rigidity portion 11 is brought into close contact with the peripheral portion of the bolt hole 3 on the upper surface of the bottom steel plate 1, and the temporary bolt fixing nut 9 Anti-loosening And fruit, are to be able to obtain the airtightness between the bolt holes 3 and the bolt temporary fixing nut 9 of the bottom steel plate 1.

  Furthermore, if the bolt temporary fixing nut 9 is made of a synthetic resin, the protruding end portion of the ring-shaped protrusion 13 can be more closely attached to the peripheral edge portion of the bolt hole 3 on the upper surface of the bottom steel plate 1. Further, the effect of preventing the bolt temporary fixing nut 9 from being loosened can be enhanced, and the airtightness between the bolt hole 3 of the bottom steel plate 1 and the bolt temporary fixing nut 9 can be further enhanced. In addition, the bolt temporary fixing nut 9 having a complicated shape having the outer peripheral surface shape of the cylindrical portion 10 and the ring-shaped protrusion 13 and the inner peripheral surface shape of the female screw portion 12 and the ring-shaped protrusion 13 can be easily formed at a time. It becomes possible to do. Therefore, the bolt temporary fixing nut 9 can be made advantageous for mass production, and the unit price can be reduced. Furthermore, the bolt temporary fixing nut 9 is exposed to the outside air with the high-strength bolt 5 temporarily fixed to the bolt hole 3 of the bottom steel plate 1, and will be described later with reference to FIG. Thus, the attachment plate 2 is placed on the bottom steel plate 1, and the nut 6 is finally tightened on the high-strength bolt 5 from the top of the attachment plate 2 to connect the bottom steel plate 1 and the attachment plate 2. Even after joining, the bolt temporary fixing nut 9 remains attached to the threaded portion 5a of the high-strength bolt 5, so that the soundness of the bolt 5 is not affected. The bolt temporary fixing nut 9 is preferably made of a synthetic resin that does not corrode.

  The axial center dimension of the bolt temporary fixing nut 9 is such that the bolt temporary fixing nut 9 screwed into the screw portion 5a of the high strength bolt 5 inserted through the bolt hole 3 of the bottom steel plate 1 from below as described above, When the ring-shaped protrusion 13 that becomes the low-rigidity portion 11 is pressed against the peripheral edge of the bolt hole 3 on the upper surface of the bottom steel plate 1 and tightened until it is deformed so as to be crushed in the axial direction, the ring-shaped protrusion Assume that the axial dimension of the bolt temporary fixing nut 9 in a state where 13 is crushed and deformed in the axial direction is set to be equal to or smaller than the thickness of the attachment plate 2. In addition, when the bottom steel plate 1 to which the high strength bolt 5 is temporarily fixed using the bolt temporary fixing nut 9 and the attachment plate 2 placed thereon are joined, the high strength bolt 5 is attached. When the washer 7 having an inner diameter larger than the outer diameter of the cylindrical portion 10 of the bolt temporary fixing nut 9 is used as the washer 7 fitted from the upper side of the plate 2, the ring-shaped protrusion 13 is pushed in the axial direction. What is necessary is just to set so that the axial direction dimension of the bolt temporary fixing nut 9 of the state clamp | tightened until it deform | transforms so that it may be crushed may become below the sum of the thickness of the said attachment board 2 and the thickness dimension of the washer 7. .

  When the bolt 5 used for joining the bottom steel plate 1 and the splicing plate 2 is temporarily fixed to the bolt hole 3 of the bottom steel plate 1 using the bolt temporary fixing nut 9 having the above configuration, first, in a factory or the like As shown in FIG. 1 (a), in the state where the high strength bolt 5 as the bolt 5 is inserted through the washer 7 from the lower surface side and held in the bolt hole 3 of the bottom steel plate 1, the bottom steel plate 1 By screwing the bolt temporary fixing nut 9 into the threaded portion 5a of the high-strength bolt 5 protruding upward from the one end side in the axial direction where the ring-shaped protrusion 13 serving as the low-rigidity portion 11 is provided. The protruding end of the ring-shaped protrusion 13 of the bolt temporary fixing nut 9 is in contact with the peripheral edge of the bolt hole 3 on the upper surface of the bottom steel plate 1.

  Next, the bolt temporary fixing nut 9 is further tightened to the threaded portion 5a of the high-strength bolt 5, whereby the bolt temporary fixing nut 9 is fastened to the high-strength bolt 5 as shown in FIG. The ring-shaped protrusion 13 as the low-rigidity portion 11 provided at one axial end of the bolt temporary fixing nut 9 is strongly pressed against the peripheral edge of the bolt hole 3 on the upper surface of the bottom steel plate 1 by force. It is made to deform so as to crush in the direction of the heart.

  At this time, the protruding end portion of the ring-shaped protrusion 13 of the bolt temporary fixing nut 9 comes into contact with the peripheral portion of the bolt hole 3 on the upper surface of the bottom steel plate 1 and the bolt is temporarily fixed by the frictional force generated at the contact portion. If it is difficult to rotate the nut 9, then if the high strength bolt 5 is a hexagonal bolt, the head 5b of the bolt 5 is rotated in the tightening direction from the lower side of the bottom steel plate 1, and the high strength bolt 5 is rotated. The bolt 5 may be fastened to the bolt temporary fixing nut 9. In addition, although not shown in the figure, when the high strength bolt 5 is used as the high strength bolt 5, the pin tail of the torcia type high strength bolt 5 is connected to the top side of the bottom steel plate 1 with a general-purpose box wrench or the like. The high-strength bolt 5 may be tightened with respect to the bolt temporary fixing nut 9 by rotating the high-strength bolt 5 in the tightening direction.

  Thereby, in the said bolt temporary fixing nut 9, the protrusion edge part of this ring-shaped protrusion 13 makes the said bottom steel plate 1 by the restoring force of the ring-shaped protrusion 13 elastically deformed so that it may be crushed in the said axial direction. Is strongly pressed against the peripheral edge of the bolt hole 3 on the upper surface of the steel plate, so that the degree of adhesion between the bolt temporary fixing nut 9 and the upper surface of the bottom steel plate 1 is increased, and a large frictional force is generated in the closely contacted portion. Co-rotation of the bolt temporary fixing nut 9 with the high strength bolt 5 is prevented.

  Therefore, the high-strength bolt 5 is temporarily fixed to the bolt hole 3 of the bottom steel plate 1 in a state where rotation is prevented by the tightening axial force with respect to the bolt temporary fixing nut 9. In addition, at this time, as described above, the ring-shaped protrusion 13 of the bolt temporary fixing nut 9 strongly adheres to the peripheral portion of the bolt hole 3 on the upper surface of the bottom steel plate 1 over the entire circumference in the circumferential direction. The space between the bolt temporary fixing nut 9 and the peripheral edge of the bolt hole 3 on the upper surface of the bottom steel plate 1 is sealed.

  After temporarily fixing the high-strength bolt 5 in the bolt hole 3 of the bottom steel plate 1 while preventing rotation as described above, a two-dot chain line in FIG. As shown, the bottom surface of the bottom steel plate 1 obtained by temporarily fixing the high-strength bolt 5 to the bolt hole 3 via the bolt temporary fixing nut 9 covers the entire surface including the head portion 5b of the high-strength bolt 5. Pre-paint. Reference numeral 14 denotes a coating film.

  Thereafter, the bottom steel plate 1 temporarily fixed in a state where the high-strength bolts 5 are prevented from rotating in the respective bolt holes 3 is carried into the construction site and arranged side by side in the span direction on the main girder, As shown in FIG. 1 (c) (only one bottom steel plate 1 is shown in FIG. 1 (c)) above the butt ends of adjacent bottom steel plates 1, the bolt holes 3 of each bottom steel plate 1 are shown. The attachment plate 2 formed by drilling a bolt hole 4 having a required dimension larger than the cylindrical portion 10 of the bolt temporary fixing nut 9 is placed from above, and the bolt hole of the attachment plate 2 is mounted. 4, the high-strength bolts 5 temporarily fixed in the bolt holes 3 of the bottom steel plate 1 are respectively inserted.

  Thereafter, the nut 6 is fitted to the threaded portion 5a of each high-strength bolt 5 protruding above the attachment plate 2 via the washer 7, and the nut 6 is fastened to the high-strength bolt 5. Thus, the overlapping portions of the bottom steel plate 1 and the splicing plate 2 are joined by the high strength bolts 5 respectively. Thereby, the butt end portions of the adjacent bottom steel plates 1 are connected to each other via the splicing plate 2.

  Thus, according to the bolt temporary fixing nut 9 of the present invention, when the high strength bolt 5 is temporarily fixed to the bolt hole 3 of the bottom steel plate 1, the threaded portion 5 a of the high strength bolt 5 of the bolt temporary fixing nut 9. The ring-shaped protrusion 13 forming the low-rigidity portion 11 is deformed so as to be crushed in the axial direction by the tightening axial force against the peripheral edge of the bolt hole 3 on the upper surface of the bottom steel plate 1 by the restoring force. It is possible to increase the degree of adhesion by pressing strongly against the part.

  Therefore, the frictional force acting between the bolt temporary fixing nut 9 and the bottom steel plate 1 can be increased, and the high strength bolt 5 is prevented from rotating in the bolt hole 3 of the bottom steel plate 1. It can be temporarily fixed with.

  For this reason, when the nut 6 is finally tightened from the upper side of the attachment plate 2 to the high-strength bolt 5 that is temporarily fixed to the bolt hole 3 of the bottom steel plate 1 at the construction site of the bottom steel plate 1, Since it is possible to prevent the high-strength bolt 5 from co-rotating, the height of the bolt hole 3 attached to the bottom surface of the bottom steel plate 1 at the factory or the like as described above. It becomes possible to perform the preceding painting including the head 5b of the force bolt 5, and thus it is possible to eliminate the need for the painting work from the lower surface side of the bottom steel plate 1 after the installation of the bottom steel plate 1, It is possible to eliminate work that requires a scaffold under the bottom steel plate 1 and work that is performed using an aerial work vehicle.

  When the high-strength bolt 5 is temporarily fixed, the bolt temporary fixing nut 9 has a protruding end portion of the ring-shaped protrusion 13 forming the low-rigidity portion 11 at the bolt hole 3 on the upper surface of the bottom steel plate 1. Therefore, it is possible to enhance tightness between the bolt temporary fixing nut 9 and the bolt hole 3 of the bottom steel plate 1. Therefore, even when the high-strength bolt 5 is temporarily fixed to the bolt hole 3 of the bottom steel plate 1 using the bolt temporary fixing nut 9 and there is a period until the bottom steel plate 1 is installed, the bottom steel plate It is possible to suppress the intrusion of moisture into the inside of one bolt hole 3 and to suppress the possibility that rust is generated at the portion located inside the bolt hole 3 of the bottom steel plate 1 in the threaded portion 5a of the high strength bolt 5. Is possible. Further, as shown by a two-dot chain line in FIG. 1 (b), the bottom includes the head 5b of the high strength bolt 5 in a state of being temporarily fixed to the bolt hole 3 of the bottom steel plate 1 via a bolt temporary fixing nut 9. Prior coating is performed on the lower surface side of the steel plate 1, and the space between the head of the high-strength bolt 5 and the lower surface of the bottom steel plate 1 is sealed with the coating film 14. It becomes possible to further enhance the rust suppressing effect of the portion located inside the bolt hole 3 of the bottom steel plate 1.

  Next, FIG. 3 shows another embodiment of the present invention, which is as follows.

  That is, the bolt temporary fixing nut 9a of the present embodiment has one axial end portion of the cylindrical portion 10 extending in the axial direction with a larger outer diameter than the bolt hole 3 provided in the bottom steel plate 1 in the axial direction. A groove 15 is provided on the outer peripheral surface of the cylindrical portion 10, and the thickness of the peripheral wall is reduced at the portion of the groove 15, so that the cylindrical portion 10 is provided at one axial end of the cylindrical portion 10. The low-rigidity portion 11 is formed in which the rigidity in the axial direction is smaller than the portion on the other end side in the axial direction with respect to the location of the groove 15 in FIG.

  Other configurations are the same as those of the bolt temporary fixing nut 9 shown in FIGS. 1A, 1B and 2 and the same components are denoted by the same reference numerals.

  When the bolt 5 used for joining the bottom steel plate 1 and the attachment plate 2 is temporarily fixed to the bolt hole 3 of the bottom steel plate 1 using the bolt temporary fixing nut 9a having the above-described configuration, Similar to the bolt temporary fixing nut 9, first, at a factory or the like, the above bolt temporary bolt 5 a is inserted into the screw portion 5 a of the high strength bolt 5 that is inserted into the bolt hole 3 of the bottom steel plate 1 through the washer 7 from below. The fixing nut 9a is screwed from one end in the axial direction where the low-rigidity portion 11 is formed, and one end in the axial direction of the bolt temporary fixing nut 9a serving as the tip of the low-rigidity portion 11 is the bottom steel plate. Then, the bolt temporary fixing nut 9a is further tightened until the low rigidity portion 11 is deformed so as to be crushed in the axial direction at the groove 15 portion. If this is done, it will push in the axial direction. Due to the restoring force of the low-rigidity portion 11 that is elastically deformed so as to be crushed, one end in the axial direction of the bolt temporary fixing nut 9a serving as the tip of the low-rigidity portion 11 is a bolt hole on the upper surface of the bottom steel plate 1. 3 is strongly pressed against the peripheral edge of the bolt 3, so that the degree of adhesion between the bolt temporary fixing nut 9a and the upper surface of the bottom steel plate 1 is increased, and a large frictional force generated at the closely contacted portion increases the height of the bolt temporary fixing nut 9. Co-rotation with the force bolt 5 is prevented.

  Therefore, the bolt temporary fixing nut 9a of the present embodiment can provide the same effects as those of the bolt temporary fixing nut 9 shown in FIGS. 1 (A), (B), and (C) and FIG.

  Next, FIGS. 4 (a), (b), (c), and (d) show modifications of the bolt temporary fixing nut 9a shown in FIG. 3 as still another embodiment of the present invention. It is.

  That is, the bolt temporary fixing nut 9b shown in FIG. 4 (a) has the same structure as the bolt temporary fixing nut 9a shown in FIG. Instead of the provided structure, the groove 16 is provided over the entire circumference on the inner peripheral surface of one axial end portion of the cylindrical portion 10, and the thickness of the peripheral wall is reduced at the groove 16 portion. A low-rigidity portion in which the rigidity in the axial direction is smaller at one end portion in the axial direction of the cylindrical portion 10 than in the portion on the other end side in the axial direction relative to the location of the groove 16 in the cylindrical portion 10 11 is formed.

  Further, the bolt temporary fixing nut 9c shown in FIG. 4 (b) has the same configuration as the bolt temporary fixing nut 9a shown in FIG. Instead of the provided structure, a groove 17 having a required depth dimension in the axial direction is provided in the intermediate portion in the radial direction (circumferential wall thickness direction) on one axial end surface of the cylindrical portion 10, The circumferential wall at one end in the axial direction of the bolt temporary fixing nut 9c is hollowed out by the groove 17 to reduce the thickness thereof, so that the one end in the axial direction of the cylindrical portion 10 is A low-rigidity portion 11 having a lower rigidity in the axial direction than the portion on the other end side of the groove 17 is formed.

  Further, the bolt temporary fixing nut 9d shown in FIG. 4 (c) has a groove 15 on the outer peripheral surface of one end in the axial direction of the cylindrical portion 10 in the same configuration as the bolt temporary fixing nut 9a shown in FIG. Instead of the provided configuration, a stepped portion 18 is provided on the outer peripheral surface of one end portion in the axial center direction of the cylindrical portion 10 so that the thickness of the peripheral wall is reduced. A low-rigidity portion 11 having a lower axial rigidity than that of the stepped portion 18 in the cylindrical portion 10 is formed at one axial end portion.

  Furthermore, the bolt temporary fixing nut 9e shown in FIG. 4 (d) has a groove 15 on the outer peripheral surface of one end in the axial direction of the cylindrical portion 10 in the same configuration as the bolt temporary fixing nut 9a shown in FIG. Is provided on the inner peripheral surface of one end in the axial direction of the cylindrical portion 10, and a step portion 19 in which the thickness of the peripheral wall is reduced is provided. A low-rigidity portion 11 having a lower axial rigidity than the stepped portion 19 in the cylindrical portion 10 is formed at one axial-direction end portion.

  In addition, in FIG. 4 (A) (B) (C) (D), the same components as those shown in FIG.

  In any of the bolt temporary fixing nuts 9b, 9c, 9d, and 9e shown in FIGS. 4 (a), (b), (c), and (d), the low rigidity portion 11 is provided at one end in the axial direction of the cylindrical portion 10. Since it is provided, the bolt 5 used for joining the bottom steel plate 1 and the splicing plate 2 is used as the bolt temporary fixing nut 9a shown in FIG. In addition, it can be temporarily fixed in a state where rotation is constrained, and the degree of adhesion between the bolt temporary fixing nuts 9b, 9c, 9d, and 9e and the upper surface of the bottom steel plate 1 can be increased, so that the bolt temporary fixing shown in FIG. The same effect as the nut 9a can be obtained.

  The present invention is not limited to the above embodiment, and the low rigidity portion provided in the temporary bolt fixing nut may have a lower axial rigidity than the cylindrical portion 10. For example, shapes other than those shown in FIGS. 2 and 3 (a), (b), (c), and (d) may be used.

  The bolt temporary fixing nuts 9, 9 a, 9 b, 9 c, 9 d, and 9 e may be used for temporarily fixing bolts other than hexagon bolts and torcia-type high-strength bolts 5.

  The bolt temporary fixing nuts 9, 9 a, 9 b, 9 c, 9 d, and 9 e are bolts 5 used for joining the bottom steel plate 1 and the attachment plate 2 when the bottom surface of the bottom steel plate 1 does not require painting. May be used when temporarily fixing to the bolt hole 3 of the bottom steel plate 1.

  Further, when joining a plurality of steel plates using bolts, if the bolt holes provided in a predetermined steel plate located on the bolt insertion side are desired to be attached in advance so as not to drop the bolts, the bottom You may apply to temporary fixation of the bolt used for joining of any steel plates other than the steel plate 1 and the splicing plate 2. Further, the present invention can be applied to a place where the high-strength bolt 5 is arranged at an angular posture other than the posture with the head 5b down.

  The temporary bolt fixing nuts 9b and 9e are attached to either the end of the axial center direction or the outer peripheral surface of the temporary bolt fixing nut 9b in FIG. 4 (a) and the temporary bolt fixing nut 9e in FIG. 4 (d). You may make it provide the mark by the notch etc. for enabling easy identification of the one end part side and other end part side of an axial direction from an external appearance.

  Of course, various modifications can be made without departing from the scope of the present invention.

1 shows an embodiment of a bolt temporary fixing nut according to the present invention, in which (a) is a state of being screwed into a high-strength bolt inserted into a bolt hole of a bottom steel plate, and (b) is tightened to a high-strength bolt. (C) is a cut-out schematic side view showing a state in which a splicing plate is joined to a bottom steel plate. It is a partially cut schematic side view which shows the volt | bolt temporary fixing nut of FIG. It is a partially cut schematic side view which shows the other form of implementation of this invention. (A), (B), (C), and (D) are all partially cut schematic side views showing still another embodiment of the present invention. It is a cut side view which shows the general connection structure through the joining board of the butt | matching edge parts of the bottom steel plate of an adjacent synthetic floor slab. An outline of an example of a conventionally proposed method for holding the bolt in the bolt hole of the bottom steel plate is shown. (A) shows a state in which the bolt is held in the bolt hole of the bottom steel plate. (C) is a cut side view showing a state in which an attachment plate is placed on the upper side of an adjacent bottom steel plate, and (c) is a cut side view showing a state in which the adjacent bottom steel plates are connected via an attachment plate.

Explanation of symbols

1 Bottom steel plate (specified steel plate)
2 Connecting plate (steel plate)
3 Bolt hole 5 High strength bolt (bolt)
5a Screw part 5b Head part 9, 9a, 9b, 9c, 9d, 9e Bolt temporary fixing nut 10 Cylindrical part 11 Low-rigidity part 12 Female thread part 13 Ring-shaped protrusion 15 Groove 16 Groove 17 Groove 18 Step part 19 Step part

Claims (4)

  In a bolt temporary fixing nut that allows the bolt to be temporarily fixed to a bolt hole of a predetermined steel plate by being screwed into a bolt for joining the plurality of steel plates by being inserted into an overlapping portion of the plurality of steel plates, A low-rigidity portion is provided on one end side in the axial direction of the cylindrical portion that has a larger diameter than the bolt hole of the predetermined steel plate and contacts the predetermined steel plate, and the rigidity in the axial direction of the low-rigidity portion is The bolt temporary fixing nut characterized by having a structure which becomes smaller than the rigidity of the other part of the axial direction of the said cylindrical part.   2. The bolt temporary fixing nut according to claim 1, wherein the low-rigidity portion is formed by a thin ring-shaped protrusion provided so as to protrude in the axial direction from one end surface in the axial direction of the cylindrical portion.   2. The bolt temporary fixing according to claim 1, wherein the low-rigidity portion is formed by providing a groove extending in the circumferential direction on the outer peripheral surface or inner peripheral surface or one axial end surface of the cylindrical portion. nut.   The bolt temporary fixing nut according to claim 1, wherein the low-rigidity portion is formed by providing a step portion having a reduced thickness of the peripheral wall on an outer peripheral surface or an inner peripheral surface of one axial end portion of the cylindrical portion. .

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