JP3212694U - Loosening prevention bolt - Google Patents

Abstract

The present invention provides a loosening prevention structural bolt that can be unfastened when the use is sufficient. A main body bolt 2 and an enlarged bolt 9 are used. The main body bolt 2 includes a head portion 2A and a shaft portion 2B. A screw hole 3 for an enlarged bolt is screwed into the shaft core portion, and a screw hole for the enlarged bolt is provided at a tip portion 2B 'of the shaft portion. 3 is provided with a cylindrical space portion 4 extending along the axial direction, and a tapered portion 5 whose diameter increases toward the outer end at the front end opening of the cylindrical space portion 4. The front end 2B 'is provided with four slots 6 along the axial direction at equal intervals in the circumferential direction, and further, the head 2A is provided with a recess 7 communicating with the screwing hole 3 of the expanded bolt. Drill. The diameter-expanded bolt 9 is screwed into a threaded hole 3 of the diameter-expanded bolt that is screwed to the main body bolt 2 so as to freely advance and retract, and a hexagonal wrench fitting hole 10 is formed on the end face of the main body bolt 2 on the head 2A side. At the same time, a tapered diameter-expanded portion 11 that is in sliding contact with the tapered portion 5 of the main body bolt 2 and that expands on the front end side is integrally coupled to a portion of the main body bolt 2 on the front end portion 2B ′ side. [Selection] Figure 3

Description

  The present invention relates to a loosening prevention bolt, and more specifically, a bolt inserted into a bolt insertion hole provided in a member to be fastened, a through bolt for fastening two members by tightening with a nut, and a bolt insertion hole penetrating both members. It can be used in two ways with the holding bolt used when it cannot be used, and when tightening with a nut, the nut can be reliably prevented from loosening due to vibration after tightening and used as a holding bolt. Occasionally, screwing with one of the members screwed into a bag-like bolt screwing hole is not loosened, and in any case, it is possible to release the tightening when there is enough use. Related to structural bolts.

  Vibration after tightening in a through bolt that is inserted into a bolt insertion hole provided in a member to be fastened and tightened with a nut to fasten two members, or a holding bolt that is used when the bolt insertion hole cannot be penetrated into both members. As one means for preventing loosening due to the like, a means using an anaerobic adhesive called a lock nut (registered trademark) is employed. The anaerobic adhesive is hardened when air is shut off by screwing a nut into a through bolt or screwing a holding bolt into a bag-like bolt screw hole screwed into one member, It eliminates the looseness of both screw threads.

  However, when such an anaerobic adhesive is used, the tightening cannot be released by the cured adhesive once used. Therefore, both members cannot be disassembled and reused, or the bolts cannot be reused.

  The present invention has been made in view of the above points, and is inserted through a bolt insertion hole provided in a member to be fastened, tightened with a nut to fasten two members, and penetrates the bolt insertion hole into both members. It can be used in two ways with the holding bolt used when it cannot be used, and when tightening with a nut, it can reliably prevent loosening of the nut due to vibration after tightening and use as a holding bolt To prevent loosening of the screw with the bag-like bolt screw hole screwed on one of the members, and further, in either case, when the use is sufficient, the loosening can be released. It is intended to provide a prevention structure bolt.

  Thus, the gist of the present invention consists of a head portion and a shaft portion, and a screwing hole for a diameter expansion bolt is screwed into the shaft core portion, and the diameter expansion bolt is provided at the tip portion of the shaft portion. A cylindrical space portion extending in the axial direction and having a diameter equal to or larger than the screw hole of the diameter-expanded bolt communicating with the screw-threading hole is provided, and a distal end opening of the cylindrical space portion is provided. The taper portion whose diameter increases toward the outer end, and four slits along the axial direction at equal intervals in the circumferential direction at the position of the cylindrical space portion at the tip end portion of the shaft portion. Further, a head bolt having a concave portion communicating with a screw hole of the enlarged bolt and a screw hole of the enlarged bolt screwed to the main body bolt are reciprocally screwed to the head. A hexagonal wrench fitting hole is drilled in an end surface of the main body bolt on the head side, and the main body bolt is formed on a tip side of the main body bolt. To sliding contact with the tapered portion of the bets, in loosening prevention structure bolt, characterized in that it consists of a integrally continuous form enlarged diameter bolts tapered enlarged diameter portion which tip side expands.

  In the above configuration, the main body bolt may have a circular head or a hexagonal head when viewed from above, and in the former case, a recess formed in the head. In the case of the latter, a concave portion having a circular shape in plan view is used as the concave portion.

  The present invention is configured as described above. Two methods of use: a through bolt that is inserted into a bolt insertion hole provided in a member to be fastened and fastened with a nut to fasten two members, and a holding bolt that is used when the bolt insertion hole cannot be penetrated into both members. Is possible.

  Then, when the diameter-expanded bolt screwed into the threaded hole of the diameter-expanded bolt screwed to the main body bolt is screwed back, that is, moved to the head side of the main body bolt, it is integrally coupled to the tip. The tapered diameter-expanded portion is in sliding contact with the tapered portion at the tip of the cylindrical space portion of the main body bolt, and gradually applies an outward force from the inside. As a result, the tip end portion of the shaft portion of the main body bolt located in the cylindrical space portion divided into four portions by slitting is expanded. Therefore, when it is used as a through-bolt, it causes strong interference between the thread of the screw and the thread of the tightened nut, and the frictional resistance becomes so strong that it does not slide, so that loosening due to vibration etc. is ensured. In addition, when used as a holding bolt, a strong interference is caused between the screw thread in the bolt and the thread of the bag-like bolt screw hole formed in one member, and the frictional resistance is reduced. It becomes strong and does not slip, and thus loosening of the screwing is surely prevented.

  Moreover, when the diameter-expanded bolt is advanced by screwing in the opposite direction to the above, the interference of the screw thread can be solved by the action opposite to the above, and in any of the above methods of use, The tightening can be released when it is sufficient. Therefore, both members can be disassembled and reused, or the bolt can be reused.

  In addition, the present invention is composed only of the main body bolt and the diameter-expanded bolt, and has a simple configuration with a small number of parts, so that it can be manufactured at a low cost.

  In addition, since the cylindrical space portion having a diameter equal to or larger than the screwing hole of the enlarged bolt is provided at the distal end portion of the shaft portion of the main body bolt, the thickness of the distal end portion of the shaft portion of the main body bolt is increased. (T in FIG. 7) is uniformly thin. Therefore, the rigidity is weakened, and the front end of the body bolt located in the cylindrical space divided into four parts by slitting is easily bent in the inner and outer directions (radial direction). In addition, since the tip end portion of the shaft portion of the main body bolt is thin by providing the cylindrical space portion in this way, the length of the tapered portion (L in FIG. 7) is also shortened. Therefore, there is a small range in which the tapered enlarged diameter portion integrally connected to the tip end portion of the enlarged bolt and the tapered portion of the main body bolt are in sliding contact, and accordingly, the frictional resistance is also reduced accordingly. As described above, the tip of the shaft portion of the main body bolt is easily bent due to the reduced thickness, and when the tapered enlarged portion of the enlarged bolt and the tapered portion of the main body bolt are in sliding contact with each other. Since the frictional resistance is reduced, it is possible to reduce the force required for screwing the diameter-expanded bolt required to expand the diameter of the tip of the shaft portion of the main body bolt.

It is a front view of the loosening prevention structure bolt concerning the embodiment of the present invention. It is the same top view. It is the sectional view on the AA line in FIG. It is a center longitudinal section front view in the state where the tip part of the main part bolt was expanded. It is a front view of a main part bolt. It is a top view of a main part bolt. FIG. 7 is a sectional view taken along line B-B in FIG. 6. It is a bottom view of a body bolt. It is a front view of a diameter expansion bolt. It is a top view of an expansion bolt. It is CC sectional view taken on the line in FIG. It is a bottom view of an expansion bolt. It is a use condition figure of the slack prevention structure bolt concerning the embodiment of the present invention, and shows the example used as a through bolt. It is a use condition figure of the loosening prevention structure bolt concerning the embodiment of the present invention, and shows the example used as a holding bolt.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  In the figure, reference numeral 1 denotes a metal loosening prevention bolt. The loosening prevention structural bolt 1 is used as a through bolt or a holding bolt.

  Reference numeral 2 denotes a main body bolt in the loosening prevention structure bolt 1. The main body bolt 2 includes a head portion 2A and a shaft portion 2B that are circular in a plan view. The main body bolt 2 is provided with a screwing hole 3 for a diameter-expanded bolt in the shaft core portion, and at the tip portion 2B ′ of the shaft portion. A cylindrical space portion 4 extending in the axial direction and having a diameter equal to or larger than that of the screw hole 3 of the enlarged bolt and communicating with the screw hole 3 of the enlarged bolt is provided. The tapered opening 5 has a tapered portion 5 whose diameter increases toward the outer end, and is equidistant in the circumferential direction at the position of the cylindrical space 4 at the distal end 2B ′ of the shaft portion. In addition, four slits 6 along the axial direction are provided, and a hexagonal recess 7 in plan view, which is a fitting hole of a hexagon wrench, communicated with the screwing hole 3 of the diameter-expanding bolt in the head 2A. Has been drilled. A slip stopper 8 is provided on the peripheral surface of the head 2A.

  Further, as the main body bolt 2, in the present embodiment, the head 2A is circular in plan view and the recess 7 is hexagonal in plan view. Although not shown, the head 2A is hexagonal in plan view. The concave portion 7 may be circular when viewed from above.

  Reference numeral 9 denotes an enlarged bolt in the loosening prevention structural bolt 1. The diameter-expanded bolt 9 is screwed into a threaded hole 3 of the diameter-expanded bolt that is screwed to the main body bolt 2 so as to freely advance and retract, and a hexagon wrench is fitted to the end face of the main body bolt 2 on the head 2A side. A hole 10 is formed, and a tapered diameter-expanding portion 11 that is in sliding contact with the tapered portion 5 of the main body bolt 2 and that expands at the front end side is integrated with a portion of the main body bolt 2 on the front end portion 2B ′ side. It is a combination of the two.

Next, the operation of the above embodiment will be described.
First, the case where it uses as a through bolt shown in FIG. 13 is demonstrated.

  The loosening prevention structural bolt 1 is inserted into the bolt insertion holes H1 and H2 provided in the members W1 and W2 to be fastened, and the two members W1 and W2 are fastened by tightening with the nut N screwed to the loosening prevention structural bolt 1. Is.

  Then, in a state where the nut N is tightened, the enlarged bolt 9 is screwed using a hexagon wrench (not shown), and the enlarged bolt 9 is moved to the head 2A side of the body bolt 2 as shown in FIG. As shown in FIG. 4, the tapered diameter-enlarged portion 11 integrally coupled to the tip end portion is in sliding contact with the taper portion 5 at the tip end of the cylindrical space portion 4 in the main body bolt 2 and gradually gradually moves from the inside to the outside. Apply the power of. And the front-end | tip part 2B 'of the axial part in the main body bolt 2 located in the cylindrical space part 4 divided | segmented into four parts by the slit 6 by this is expanded. Therefore, strong interference is caused between the screw thread of the shaft portion 2B in the loosening prevention structural bolt 1 and the screw thread of the nut N screwed to the screw bolt, and the frictional resistance becomes strong, so that it does not slide, and thus is caused by vibration or the like. Looseness is surely prevented. Further, when unfastening the nut N, the diameter-expanded bolt 9 is screwed in the direction opposite to the above using a hexagon wrench to return the tip end portion 2B 'of the shaft portion of the main body bolt 2 to the original diameter. . As a result, the interference of the screw threads is released and the nut N can be turned. Then, tightening can be released by removing the nut N from the shaft portion 2B of the body bolt 2 thereafter.

  Next, the case where it uses as a holding bolt shown in FIG. 14 is demonstrated.

  In FIG. 14, when the bolt insertion holes cannot be penetrated in both members, that is, one member W3 can be provided with a bolt insertion hole H3, but the other member W4 cannot be provided with a bolt insertion hole. In this case, a bag-like bolt screw hole W4 ′ is screwed into one member W4, and the shaft portion 2B of the main body bolt 2 is screwed into the bolt screw hole W4 ′. . Then, in a state where the shaft portion 2B of the main body bolt 2 is passed through the bolt insertion hole 13 of one member 3, the tip end side is screwed into the bolt screwing hole W4 'of the other member W4, and finally the above-mentioned Similarly, the expansion bolt 9 is screwed to cause strong interference of the thread. Further, the same operation as described above is performed when the strong interference of the screw thread is solved.

  In addition, the embodiment of the present invention is as described above, and is configured only by the main body bolt 2 and the diameter-expanded bolt 9 and has a simple configuration with a small number of parts, and thus can be manufactured at low cost. is there.

  Moreover, since the cylindrical space portion 4 having a diameter equal to or larger than that of the screw hole 3 of the enlarged bolt is provided at the tip portion 2B ′ of the shaft portion of the main body bolt 2, the shaft portion of the main body bolt 2 is provided. The wall thickness (T in FIG. 7) of the tip 2B ′ is uniformly reduced. Therefore, since the rigidity is weakened, the front end portion 2B ′ of the shaft portion of the main body bolt 2 located in the cylindrical space portion 4 divided into four portions by the slit 6 is easily bent in the inner and outer directions (radial direction). It has become. In addition, since the cylindrical space portion 4 is provided in this manner, the tip end portion 2B ′ of the shaft portion of the main body bolt 2 is thinned, so that the length of the tapered portion 5 (L in FIG. 7) is also short. It has become. Therefore, there is a small range in which the tapered enlarged diameter portion 11 integrally coupled to the tip end portion of the enlarged diameter bolt 9 and the tapered portion 5 of the main body bolt 2 are in sliding contact, and accordingly, the frictional resistance is reduced accordingly. As described above, the shaft tip end 2B ′ of the main body bolt 2 is easily bent due to the reduced thickness, and the tapered enlarged diameter portion 11 of the enlarged diameter bolt 9 and the taper of the main body bolt 2 are increased. By reducing the frictional resistance at the time of sliding contact with the portion 5, it is possible to reduce the force required for screwing the diameter-expanded bolt 9 when the diameter of the tip portion 2B 'of the shaft portion of the main body bolt 2 is expanded. It can be done.

DESCRIPTION OF SYMBOLS 1 Loosening prevention structure bolt 2 Main body bolt 2A Main body bolt head 2B Main body bolt shaft portion 2B 'End portion of main body bolt shaft portion 3 Enlarged bolt screwing hole 4 Cylindrical space portion 5 Tapered portion 6 Slot 7 Recessed part 9 Expanded bolt 10 Hexagonal wrench fitting hole 11 Tapered expanded part

Claims (3)

  The expansion bolt includes a head portion and a shaft portion, and a screw hole for a diameter expansion bolt is screwed to the shaft core portion, and the tip portion of the shaft portion communicates with the screw hole of the diameter expansion bolt. A cylindrical space portion extending in the axial direction and having a diameter equal to or larger than the screw hole is provided, and a tapered portion that expands in diameter toward the outer end of the distal end opening of the cylindrical space portion; At the same time, four slits along the axial direction are provided at equal intervals in the circumferential direction at the position of the cylindrical space portion at the tip of the shaft portion, and the head is further provided with A main body bolt having a recess communicating with the screw hole, and a screw hole of an enlarged bolt bolted to the main body bolt are removably screwed, and a hexagon wrench is attached to an end surface of the main body bolt on the head side. A front end side that is in sliding contact with the tapered portion of the main body bolt is formed on the front end side portion of the main body bolt. Loosening prevention structure bolt, characterized in that it consists of a integrally continuous form enlarged diameter bolts tapered enlarged diameter portion to the large.   2. The loosening prevention structural bolt according to claim 1, wherein the head of the main body bolt is a circular head in plan view, and the recess is a hexagonal recess in plan view.   The loosening prevention bolt according to claim 1, wherein the head of the main body bolt is a hexagonal head when viewed from above and the recess is a circular recess when viewed from above.

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