JP2017219062A - Bolt fastening structure and outdoor installation housing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure waterproofness of a box nut in an environment below a freezing point.SOLUTION: A box nut 4 has: a nut part 4a into which a bolt 3 is screwed; a bag part 4b covering a tip of the bolt 3 screwed into the nut part 4a; and a viscous resin material 4c loaded into the bag part 4b and filling a gap between the bag part 4b and the tip of the bolt 3. The box nut 4 prevents entry of water into the bag part 4b.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bolt fastening structure that ensures waterproofness and an outdoor installation housing to which the bolt fastening structure is applied.

  Conventionally, for example, bolts and nuts are used as a fastening structure for fixing components constituting the casing. In an outdoor installation case installed outdoors, a cap is attached to the tip of a bolt or nut exposed outside the case to prevent rainwater and the like from entering the inside of the case, and a sealing material is filled inside the cap. (For example, refer to Patent Document 1). In the case of this structure, the sealing material filled in the cap is prevented from being deteriorated by being protected from direct sunlight and wind and rain. On the other hand, there are many components such as a cap, a mounting bolt for fixing the cap, and a rubber packing for preventing rainwater and the like from entering the cap, and the assembly workability is poor. In addition, it is difficult to form a structure for installing rubber packing in the thin plate portion of the cap. When the outer periphery of the fastening portion between the cap and the mounting bolt is welded instead of the rubber packing, water can be prevented from entering from the fastening portion, but it is difficult to remove the parts once assembled.

  Patent Document 2 describes a structure in which a recess is formed between a screw tip surface of a bolt and a tip surface of a nut, and the recess is filled with a filler, and then a bolt and a nut are subjected to rust-proof coating. Has been. Even if the screw of the bolt has a sharp part such as the sharp part of the pin tail fracture surface or the tip of the screw thread, these do not protrude from the nut tip surface, and the rust preventive paint and filler in the recess Since the film is buried, the film thickness of the rust preventive paint can be secured even at a pointed portion, and rusting due to the insufficient film thickness can be prevented. On the other hand, after filling the filler and applying the anticorrosive paint, it becomes difficult to remove the parts, and therefore it cannot be repeatedly fastened. Further, it is not possible to prevent water from entering from the gap between the bolt or nut and the member to be fastened. Even when a rust-proof paint is applied for the purpose of waterproofing, the film thickness varies greatly and it is difficult to ensure a certain waterproof property.

  In the case of a case that is used in an environment where water falls or a case that circulates water inside, a bag with a bag part welded to the end of the nut as a structure that prevents water from entering or leaking from the fastening part Some use nuts (see, for example, Patent Document 3). If the airtightness of the bag portion is maintained, water does not enter the casing through the screw or leak to the outside of the casing. Further, since the fastening structure is waterproofed by the cap nut, it is not necessary to weld the outer periphery of the fastening portion between the cap and the mounting bolt as in Patent Document 1, and rubber packing or the like is unnecessary.

Japanese Utility Model Publication No. 6-14530 JP 2009-52602 A JP 2007-32769 A

  In the conventional cap nut, the water that has entered the bag portion is not discharged and remains. Therefore, when the outdoor installation housing is installed in a sub-freezing environment, the water remaining in the bag nut's bag part freezes and the welded part between the bag part and the nut breaks due to the expansion of the water at the time of freezing. There was a problem that would be damaged.

  The present invention has been made to solve the above-described problems, and an object thereof is to ensure the waterproofness of the cap nut even in a sub-freezing environment.

  The bolt fastening structure according to the present invention includes a bolt and a cap nut for fastening members to be fastened, and the cap nut covers a nut portion into which the bolt is screwed and a tip portion of the bolt screwed into the nut portion. And a viscous resin material filled in the bag portion and filling the gap between the bag portion and the tip of the bolt.

  According to the present invention, since the bag portion of the cap nut is filled with the viscous resin material that fills the gap between the cap portion and the tip of the bolt, water intrusion into the cap portion of the cap nut is prevented. can do. Therefore, the waterproofness of the cap nut can be ensured even in a sub-freezing environment.

It is an external view which shows the bolt fastening structure of the outdoor installation housing | casing which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the bolt fastening structure of the outdoor installation housing | casing which concerns on Embodiment 1. FIG. It is an external view which shows the bolt fastening structure of the outdoor installation housing | casing which concerns on Embodiment 2 of this invention. It is sectional drawing which shows the bolt fastening structure of the outdoor installation housing | casing which concerns on Embodiment 2. FIG. FIG. 10 is an external view showing a modification of the bolt fastening structure of the outdoor installation housing according to the second embodiment. It is a top view of the washer shown as a modification of the bolt fastening structure of the outdoor installation case concerning Embodiment 2. It is an external view which shows the bolt fastening structure of the outdoor installation housing | casing which concerns on Embodiment 3 of this invention. It is an external view which shows the bolt fastening structure of the outdoor installation housing | casing which concerns on Embodiment 4 of this invention.

Embodiment 1 FIG.
FIG. 1 is an external view showing a bolt fastening structure for an outdoor installation housing according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view. However, only the bolt 3 is shown in FIG. The outdoor installation housing is installed in an outdoor environment where water may fall. The outdoor installation housing includes fastened members 1 and 2 that are housing base materials. The fastened members 1 and 2 are fastened by a bolt fastening structure using the bolt 3 and the cap nut 4.

  The bolt 3 includes a head portion 3a and a male screw-shaped screw portion 3b. A washer 5 is installed between the fastened member 1 and the bolt 3. The washer 5 is not an essential part and can be omitted. In the fastened members 1 and 2, a hole through which the screw portion 3 b of the bolt 3 passes is formed.

  The cap nut 4 includes a nut portion 4a into which the bolt 3 is screwed, a bag portion 4b that covers the tip portion of the screw portion 3b of the bolt 3, and a tip portion of the bag portion 4b and the screw portion 3b of the bolt 3 that is filled in the bag portion 4b. And a viscous resin material 4c that fills the gap with the portion. The nut portion 4a has a penetrating nut shape, and a female screw that meshes with the screw portion 3b is formed inside. Moreover, the to-be-fastened member 2 is welded to one end part of the nut part 4a, and the bag part 4b is welded to the other end part. The inside of the nut portion 4a communicates with the inside of the bag portion 4b through the hole 4d. In the illustrated example, the bag portion 4b is hemispherical, but the shape is free. The resin material 4c is a viscous resin such as a sealing material filled in the internal space of the bag portion 4b. The resin material 4c is a material that does not expand due to freezing or is difficult to expand, and has a higher viscosity than water and poor fluidity. The resin material 4c is, for example, silicone.

Next, the fastening procedure of the bolt 3 will be described.
The operator first welds the nut portion 4a of the cap nut 4 to the edge portion of the hole formed in the fastened member 2, and fills the bag portion 4b with the resin material 4c. The operator manages the filling amount of the resin material 4c so that there is no gap between the tip of the screw portion 3b and the bag portion 4b when the bolt 3 is fastened to the cap nut 4. In the illustrated example, an amount of the resin material 4c equal to the volume of the bag portion 4b is filled. Subsequently, the operator fastens the bolt 3 to the cap nut 4 with the positions of the holes of the fastened members 1 and 2 being aligned. At this time, the screw 3b of the bolt 3 is screwed into the nut 4a of the cap nut 4, and the tip of the screw 3b reaches the cap 4b. Since the bag portion 4b is filled with a viscous resin material 4c, the gap between the bag portion 4b and the tip of the screw portion 3b is filled with the resin material 4c.

Next, the waterproofness of the bolt fastening structure will be described.
Assume that the head 3a side of the bolt 3 is outside the casing, and the cap nut 4 side is inside the casing. As indicated by an arrow A, rainwater or the like passes from the gap between the head 3a and the washer 5 or the gap between the washer 5 and the fastened member 1 through the gap between the screw portion 3b and the nut portion 4a to the bag portion 4b. And infiltrate. Since airtightness is maintained by welding between the member to be fastened 2 and the nut portion 4a and between the nut portion 4a and the bag portion 4b, even if water enters as shown by the arrow A, the bag Water does not leak from the nut 4. Therefore, the waterproofness inside the housing is maintained.

Further, since the inside of the bag portion 4b is filled with the resin material 4c having a higher viscosity than water, even if water enters as shown by the arrow A, it cannot enter the bag portion 4b.
When the inside of the bag part 4b is not filled with the resin material 4c and is hollow, water enters the bag part 4b and remains. When the water accumulated in the full bag portion 4b freezes and expands in a sub-freezing environment, a load is applied to the bag portion 4b and the nut portion 4a, the welded portion between the bag portion 4b and the nut portion 4a is damaged, and the waterproof property is impaired. May be. On the other hand, in Embodiment 1, since water cannot enter into the bag portion 4b, damage to the welded portion due to freezing and expansion of water can be prevented, and the waterproofness is not impaired. Further, since the resin material 4c is selected as a material that does not expand due to freezing, even if the resin material 4c is frozen in a sub-freezing environment, the bag portion 4b and the nut portion 4a are not loaded, and the bag Damage to the welded portion between the portion 4b and the nut portion 4a can be prevented, and the waterproofness is not impaired.

  As described above, the bolt fastening structure according to Embodiment 1 includes the bolt 3 and the cap nut 4 that fasten the fastened members 1 and 2, and the cap nut 4 includes the nut portion 4 a into which the bolt 3 is screwed. And a bag portion 4b covering the tip portion of the bolt 3 screwed into the nut portion 4a, and a viscous resin material 4c filled in the bag portion 4b and filling the gap between the bag portion 4b and the tip portion of the bolt 3. It is a configuration. With this configuration, it is possible to prevent water from entering the bag portion 4 b of the cap nut 4. In addition, since the waterproofness of the cap nut 4 in a sub-freezing environment can be ensured by preventing water from entering the bag portion 4b, when this bolt fastening structure is applied to an outdoor casing device, the cap nut 4 can be used outdoors even in a sub-freezing environment. The waterproofness of the casing device can be secured.

  In addition, the resin material 4c may be accommodated in the capsule. In the case of this configuration, a capsule containing a viscous resin material 4c is placed inside the bag portion 4b, and the tip of the screw portion 3b screwed into the nut portion 4a comes into contact with the capsule. Then, the capsule is broken by the pressure generated when the bolt 3 is fastened to the cap nut 4, and the resin material 4c flows out of the capsule and fills the gap between the bag portion 4b and the tip portion of the screw portion 3b. By accommodating the viscous resin material 4c in the capsule, the operation of filling the bag portion 4b with the resin material 4c becomes unnecessary. Further, since the resin material 4c does not adhere to the thread portion of the cap nut 4 when the resin material 4c is filled in the bag portion 4b, the cap nut 4 is fastened between the cap nut 4 and the bolt 3 when the bolt 3 is fastened. It is possible to prevent the resin material 4 c from being sandwiched and prevent the resin material 4 c from causing insufficient tightening torque of the bolt 3 and loosening of the bolt 3.

Embodiment 2. FIG.
In Embodiment 1, the resin material 4c with viscosity was filled in the internal space of the bag part 4b. In this configuration, if the filling amount of the resin material 4c is too large, the bolt 3 cannot be fully tightened, or the bag portion 4b is loaded by the internal pressure of the cap nut 4 generated when the bolt 3 is tightened. There is a possibility that the welded portion between 4b and the nut portion 4a may be damaged. Therefore, in the bolt fastening structure according to Embodiment 1, it is necessary to manage the filling amount of the resin material 4c. On the other hand, in Embodiment 2, it is set as the bolt fastening structure which does not need to manage the filling amount of the resin material 4c.

  3 is an external view showing a bolt fastening structure for an outdoor installation housing according to Embodiment 2 of the present invention, and FIG. 4 is a cross-sectional view. However, only the bolt 3 is shown in FIG. 3 and FIG. 4, the same or corresponding parts as those in FIG. 1 and FIG.

  In the second embodiment, the bolt 3 has a discharge path 3c for discharging the resin material 4c filled in the bag portion 4b from the bag portion 4b. The discharge path 3c is, for example, a groove extending from the distal end portion of the screw portion 3b to the edge of the head portion 3a.

  When the screw portion 3b of the bolt 3 is screwed into the nut portion 4a of the cap nut 4, the excess resin material 4c filled beyond the volume of the cap portion 4b passes through the discharge passage 3c as indicated by an arrow B. It passes through and is discharged to the outside of the bag portion 4b. In the illustrated example, since the discharge passage 3c extends from the tip of the screw portion 3b to the edge of the head portion 3a, the resin material 4c discharged from the bag portion 4b to the discharge passage 3c when the bolt 3 and the cap nut 4 are fastened is As it is, it is discharged out of the casing through the discharge path 3c. Since the excess resin material 4c is discharged, the bolt 3 is not completely tightened, and pressure is not generated inside the bag portion 4b and the nut portion 4a, so that the welded portions of both are not damaged. Sex can be secured. Moreover, since it is not necessary to manage the filling amount of the resin material 4c, the workability when filling the bag portion 4b with the resin material 4c is improved.

  In the second embodiment, when the screw portion 3b of the bolt 3 is screwed into the nut portion 4a of the cap nut 4, the tip portion of the screw portion 3b communicates the nut portion 4a and the bag portion 4b. It is configured to enter the hole 4d and reach the inside of the bag portion 4b. The diameter of the hole 4d is assumed to be larger than the outer diameter of the screw portion 3b. With this configuration, excess resin material 4c is discharged to the outside of the bag portion 4b through the gap between the hole 4d and the screw portion 3b. The resin material 4c discharged to the outside of the bag portion 4b is discharged to the outside of the housing through the discharge path 3c of the screw portion 3b.

  In addition to providing the discharge path 3 c in the bolt 3, a through hole communicating with the discharge path 3 c may be provided in at least one of the cap nut 4 or the washer 5.

With reference to FIG. 5, the example in the case of providing the hole 7 in the cap nut 4 is demonstrated. FIG. 5 is an external view of the bolt fastening structure.
In Embodiment 1, the outer peripheral part of the to-be-fastened member 2 and the nut part 4a of the cap nut 4 is welded without gap. On the other hand, in Embodiment 2, the outer peripheral part of the to-be-fastened member 2 and the nut part 4a is welded by dividing | segmenting into a fixed area in a jump. By welding the outer peripheral portion of the fastened member 2 and the nut portion 4a by so-called stepping stone welding, a gap between the welded portions 6 becomes a through hole 7 of the resin material 4c. With this configuration, excess resin material 4 c that has flowed out toward the head 3 a through the discharge path 3 c of the bolt 3 protrudes from the through hole 7 and escapes to the outside of the cap nut 4. Therefore, tightening of the bolt 3 is incomplete, and pressure is not generated inside the bag portion 4b and the nut portion 4a, so that the welded portion is not damaged, and waterproofness can be secured. Moreover, since it is not necessary to manage the filling amount of the resin material 4c, the workability when filling the bag portion 4b with the resin material 4c is improved.

With reference to FIG. 6, the example in the case of providing the through hole 5a in the washer 5 is demonstrated. FIG. 6 is a plan view of the washer 5.
The washer 5 has a through hole 5a for discharging the resin material 4c in the discharge path 3c of the bolt 3 to the outside. The through hole 5a is, for example, a groove extending from the inner peripheral edge to the outer peripheral edge of the washer 5. With this configuration, the excess resin material 4 c that has flowed out toward the head 3 a through the discharge path 3 c of the bolt 3 protrudes from the through hole 5 a and escapes to the outside of the cap nut 4. Therefore, tightening of the bolt 3 is incomplete, and pressure is not generated inside the bag portion 4b and the nut portion 4a, so that the welded portion is not damaged, and waterproofness can be secured. Moreover, since it is not necessary to manage the filling amount of the resin material 4c, the workability when filling the bag portion 4b with the resin material 4c is improved.

  As described above, in the bolt fastening structure according to the second embodiment, the bag portion 4b of the cap nut 4 is formed with the hole 4d communicating with the nut portion 4a, and the tip portion of the screw portion 3b of the bolt 3 is a hole. It is the structure which enters 4d. With this configuration, excess resin material 4c in the bag portion 4b can be discharged from the gap between the tip portion of the screw portion 3b and the hole 4d. Therefore, tightening of the bolt 3 is incomplete, and pressure is not generated inside the bag portion 4b and the nut portion 4a, so that the welded portion is not damaged, and waterproofness can be secured. Moreover, since it is not necessary to manage the filling amount of the resin material 4c, the workability when filling the bag portion 4b with the resin material 4c is improved.

  According to the second embodiment, the bolt 3 has a head 3a, a male screw-shaped screw 3b, and a groove extending from the tip of the screw 3b to the edge of the head 3a. In this structure, the resin material 4c is discharged from the bag portion 4b. With this configuration, when the bolt 3 and the cap nut 4 are fastened, the excess resin material 4c in the bag portion 4b can be discharged. Therefore, tightening of the bolt 3 is incomplete, and pressure is not generated inside the bag portion 4b and the nut portion 4a, so that the welded portion is not damaged, and waterproofness can be secured. Moreover, since it is not necessary to manage the filling amount of the resin material 4c, the workability when filling the bag portion 4b with the resin material 4c is improved.

  Further, according to the second embodiment, the washer 5 installed between the fastened member 1 and the bolt 3 has a through hole 5a for discharging the resin material 4c in the discharge path 3c to the outside. Good. Even in this configuration, when the bolt 3 and the cap nut 4 are fastened, the excess resin material 4c in the bag portion 4b can be discharged.

  Further, according to the second embodiment, the cap nut 4 may be in a state where the to-be-fastened member 2 is stepped stone welded. In the case of this configuration, the gap between the welded portions 6 formed in a jump is defined as a through hole 7 for discharging the resin material 4c in the discharge path 3c to the outside. Therefore, when the bolt 3 and the cap nut 4 are fastened, the excessive resin material 4c in the bag portion 4b can be discharged.

Embodiment 3 FIG.
In the second embodiment, the viscous resin material 4c is filled in the internal space of the bag portion 4b. On the other hand, in the third embodiment, the resin material 4c is not filled in the internal space of the bag portion 4b and is left hollow.

  FIG. 7 is an external view showing a bolt fastening structure for an outdoor installation housing according to Embodiment 3 of the present invention. In FIG. 7, the same or corresponding parts as those in FIGS.

  In the third embodiment, the bolt 3 is formed with a discharge path 3c. The bag portion 4b of the cap nut 4 is hollow inside. The end of the nut portion 4a on the fastened member 2 side is welded to the fastened member 2 without a gap. In the case of this configuration, rainwater or the like enters the bag portion 4b from the gap between the head 3a and the washer 5 or the gap between the washer 5 and the fastened member 1 through the gap between the screw portion 3b and the nut portion 4a. And accumulate. When the water accumulated in the bag portion 4b is frozen, the discharge passage 3c becomes an escape route for the expanded water. Therefore, even if the water in the bag portion 4b freezes in a sub-freezing environment, the bag portion 4b and the nut portion 4a are not loaded, and damage to the welded portion between the bag portion 4b and the nut portion 4a can be prevented. There is no loss of water resistance. Further, since the operation of filling the resin material 4c into the bag portion 4b is not required, the resin material 4c is not sandwiched between the bolt 3 and the cap nut 4, and the resin material 4c is insufficient in the tightening torque of the bolt 3. Further, it is possible to prevent the bolt 3 from becoming loose.

  As described above, the bolt fastening structure according to Embodiment 3 includes the bolt 3 and the cap nut 4 that fasten the fastened members 1 and 2, and the cap nut 4 includes the nut portion 4 a into which the bolt 3 is screwed. And a bag portion 4b covering the tip portion of the bolt 3 screwed into the nut portion 4a. The bolt 3 includes a head portion 3a, a male screw shape screw portion 3b, and a head portion from the tip portion of the screw portion 3b. And a groove extending to the edge of 3a, and this groove serves as a discharge path 3c for discharging water that has entered the bag portion 4b. With this configuration, the waterproofness of the cap nut 4 in a sub-freezing environment can be ensured. Therefore, when this bolt fastening structure is applied to an outdoor installation casing, the waterproofing of the outdoor casing apparatus can be ensured even in a sub-freezing environment.

Embodiment 4 FIG.
In Embodiment 1, the resin material 4c with viscosity was filled in the internal space of the bag part 4b. On the other hand, in Embodiment 4, a damper is installed in the internal space of the bag part 4b.

  FIG. 8 is an external view showing a bolt fastening structure for an outdoor housing according to Embodiment 4 of the present invention. 8 that are the same as or correspond to those in FIG. 1 and FIG.

  In the fourth embodiment, a damper 8 is installed in the internal space of the bag portion 4b. The damper 8 absorbs volume deformation due to freezing and expansion of water accumulated in the bag portion 4b. Examples of the material of the damper 8 include a closed cell sponge or a balloon. In the case of this configuration, rainwater or the like enters the bag portion 4b from the gap between the head 3a and the washer 5 or the gap between the washer 5 and the fastened member 1 through the gap between the screw portion 3b and the nut portion 4a. And accumulate. When the water accumulated in the bag portion 4b is frozen, the damper 8 is deformed to absorb volumetric deformation due to freezing and expansion of water. Therefore, even if the water in the bag portion 4b freezes in a sub-freezing environment, the bag portion 4b and the nut portion 4a are not loaded, and damage to the welded portion between the bag portion 4b and the nut portion 4a can be prevented. There is no loss of water resistance. Further, since the operation of filling the resin material 4c into the bag portion 4b is not required, the resin material 4c is not sandwiched between the bolt 3 and the cap nut 4, and the resin material 4c is insufficient in the tightening torque of the bolt 3. Further, it is possible to prevent the bolt 3 from becoming loose. Further, when filling the bag 4b with the resin material 4c, it is necessary to refill the resin material 4c every time the bolt 3 is removed. However, if the damper 8 is used, the bolt 3 is repeatedly attached and detached without any special work. be able to.

  As described above, the bolt fastening structure according to Embodiment 4 includes the bolt 3 and the cap nut 4 that fasten the fastened members 1 and 2, and the cap nut 4 includes the nut portion 4 a into which the bolt 3 is screwed. The bag portion 4b covers the tip of the bolt 3 screwed into the nut portion 4a, and the damper 8 is installed in the bag portion 4b. With this configuration, the volume deformation when the water that has entered the bag portion 4b freezes and expands is absorbed by the damper 8, and the waterproof property of the cap nut 4 in a sub-freezing environment is ensured. Therefore, when this bolt fastening structure is applied to an outdoor installation housing, the waterproofness of the outdoor housing device can be ensured even in a freezing environment.

  In the present invention, within the scope of the invention, any combination of each embodiment, any component of each embodiment can be modified, or any component of each embodiment can be omitted.

  In addition, the bolt fastening structure described in each embodiment of the present invention is not limited to application to an outdoor installation casing, and may be applied to a casing such as a valve device that circulates water inside. Also good. When the bolt fastening structure is applied to a housing such as a valve device that circulates water inside, it is possible to prevent water from leaking to the outside.

  1, 2 Fastened member, 3 bolt, 3a head, 3b screw part, 3c discharge path, 4 cap nut, 4a nut part, 4b bag part, 4c resin material, 4d hole, 5 washer, 5a, 7 through hole, 6 Welded part, 8 damper.

Claims (9)

It is equipped with a bolt and a cap nut for fastening members to be fastened together,
The cap nut includes a nut portion into which the bolt is screwed, a bag portion covering a tip portion of the bolt screwed into the nut portion, a bag portion filled with the bag portion, and a tip portion of the bolt. A bolt fastening structure comprising: a viscous resin material filling the gap.   The bolt fastening structure according to claim 1, wherein the resin material is accommodated in a capsule that is broken by contact of a tip portion of the bolt.   The bolt fastening structure according to claim 1, wherein a hole communicating with the nut portion is formed in the bag portion, and a tip portion of the bolt enters the hole.   The bolt has a head portion, a male screw-shaped screw portion, and a groove extending from a tip portion of the screw portion to an edge of the head portion, and the groove discharges the resin material from the bag portion. The bolt fastening structure according to claim 1, wherein the bolt fastening structure is a road. A washer installed between the fastened member and the bolt;
5. The bolt fastening structure according to claim 4, wherein the washer has a through hole for discharging the resin material in the discharge path to the outside.   The cap nut is in a state where a stepping stone is welded to the fastened member, and a gap between the welded portions formed in a jump is a through hole for discharging the resin material in the discharge path to the outside. The bolt fastening structure according to claim 4. It is equipped with a bolt and a cap nut for fastening members to be fastened together,
The cap nut has a nut portion into which the bolt is screwed, and a bag portion covering a tip portion of the bolt screwed into the nut portion,
The bolt has a head portion, a male screw-shaped screw portion, and a groove extending from a tip portion of the screw portion to an edge of the head portion, and the groove discharges water that has entered the bag portion. Bolt fastening structure characterized by being a road. It is equipped with a bolt and a cap nut for fastening members to be fastened together,
The cap nut has a nut portion into which the bolt is screwed, a bag portion covering a tip portion of the bolt screwed into the nut portion, and a damper installed in the bag portion. Fastening structure.   The outdoor installation housing | casing provided with the bolt fastening structure of any one of Claims 1-8, and the to-be-fastened members which are housing | casing base materials are fastened by the said bolt fastening structure.

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