Anti-loosening sleeve, fastening structure, and fastening method

Abstract

To exert anti-loosening effect with a simple configuration.SOLUTION: An anti-loosening sleeve 2 includes: an annular washer 3 having a through-hole 3a through which a fastening bolt 10 is inserted and interposed between a member to be fastened 12 and a bolt head 10a of the fastening bolt 10 or a nut 11; and a cylindrical sleeve part (sleeve body 2a) projecting in an axial direction more than the washer 3 and fastened while being interposed between an outer periphery of a male screw part 10b of the fastening bolt 10 and an inner periphery of a bolt insertion hole 12a' of a member to be fastened 12' or a female screw part 11a of the nut 11.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present invention relates to a locking sleeve, a fastening structure, and a fastening method that are sandwiched and tightened between a male screw portion of a fastening bolt and a female screw portion of a nut or a fastened member.

Background Art

[0002] Conventionally, various anti-loosening structures for fastening bolts have been known. For example, as in Patent Document 1, a metal nut having a concave portion on the seating surface and a metal washer having a raised center are used. When the fastening bolt is screwed in, the center portion of the washer is deformed along the inclined surface of the nut concave portion, and a fastening structure for pressing the male screw portion of the fastening bolt is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The anti-loosening structure of the fastening bolt is preferably easy to work with and can use fastening bolts and nuts of general shapes. However, in the anti-loosening structure of Patent Document 1, it is necessary to prepare a dedicated nut having a special shape, and moreover, there is a problem that it cannot be applied when directly screwing into a general female screw portion formed on the fastened member without using a special nut.

[0005] The present invention has been made in view of such points, and an object thereof is to enable an anti-loosening effect to be exhibited with a simple configuration.

Means for Solving the Problems

[0006] To achieve the above objective, this invention provides a mechanism that prevents loosening by screwing the anti-loosening sleeve onto the female threaded portion of the fastening bolt using the male threaded portion of the fastening bolt.

[0007] Specifically, the anti-loosening sleeve of the first invention comprises an annular flange portion having a through hole through which a fastening bolt is inserted, and a cylindrical sleeve portion extending axially from the flange portion and being sandwiched and tightened between the outer circumference of the male threaded portion of the fastening bolt and the inner circumference of the bolt insertion hole of the fastened member or the female threaded portion of the nut.

[0008] With the above-described anti-loosening sleeve, the cylindrical sleeve portion is tightened while sandwiched between the outer circumference of the male threaded portion of the fastening bolt and the female threaded portion of the bolt insertion hole on the inner circumference of the fastened member or the female threaded portion of the nut. As a result, the male and female threaded portions are tightly fitted together, and the fastening bolt does not loosen. Furthermore, since the sleeve portion is tightened by the male and female threaded portions, it can be applied to fastened members that have a typical female threaded portion.

[0009] The second invention is, A locking sleeve having an annular flange portion with a through hole through which a fastening bolt is inserted, and a cylindrical sleeve portion extending axially from the flange portion, The present invention relates to a fastening structure in which the fastened member is fastened by an annular washer having a through hole through which the sleeve portion is inserted, and which is sandwiched between the fastened member and the bolt head or nut of the fastening bolt. In the aforementioned fastening structure, The fastened member is tightened with the sleeve portion sandwiched between the outer circumference of the male threaded portion of the fastening bolt and the inner circumference of the bolt insertion hole of the fastened member or the female threaded portion of the nut.

[0010] According to the fastening structure described above, the cylindrical sleeve portion is tightened while sandwiched between the outer circumference of the male threaded portion of the fastening bolt and the female threaded portion of the bolt insertion hole on the inner circumference of the fastened member or the female threaded portion of the nut. As a result, the male and female threaded portions are tightly fitted together, and the fastening bolt does not loosen. Furthermore, since the sleeve portion is tightened between the male and female threaded portions, it can be applied to fastened members that have a typical female threaded portion.

[0011] In the third invention, in the second invention, The flange portion is thinner than the washer, has a smaller outer diameter than the washer, and is fitted into a circular groove recessed on the inner circumference of the through hole of the washer.

[0012] According to the above configuration, the thin flange portion and the washer can be molded separately, and the material of the exposed washer can be made of a material with high weather resistance, while the material of the anti-loosening sleeve having a flange portion covered by the washer can be selected prioritizing anti-loosening effect over weather resistance.

[0013] In the fourth invention, in the second invention, The flange portion is thinner than the washer, has the same outer diameter as or smaller than the washer, and is sandwiched between the axial end face of the washer and the bolt head or the nut.

[0014] According to the above configuration, the thin flange portion and the washer can be molded separately. The exposed washer material can be made of a material with high weather resistance, and the material for the anti-loosening sleeve, which has a flange portion whose axial end face is covered by the washer, can be selected prioritizing anti-loosening effect over weather resistance. In addition, since there is no need to provide a circular groove in the washer itself, it is possible to use a washer of a general shape.

[0015] The anti-loosening sleeve of the fifth invention has a through hole through which a fastening bolt is inserted, and an annular washer portion that is sandwiched between the fastened member and the bolt head or nut of the fastening bolt, The device comprises a cylindrical sleeve portion that extends integrally from the washer portion in the axial direction and is sandwiched and tightened between the outer circumference of the male threaded portion of the fastening bolt and the inner circumference of the bolt insertion hole of the fastened member or the female threaded portion of the nut.

[0016] According to the above configuration, the cylindrical sleeve portion is tightened while sandwiched between the outer circumference of the male threaded portion of the fastening bolt and the female threaded portion of the bolt insertion hole on the inner circumference of the fastened member or the female threaded portion of the nut. As a result, the male and female threaded portions are tightly fitted together, and the fastening bolt does not loosen. Furthermore, since the sleeve portion is tightened between the male and female threaded portions, a special nut is not required, and it can be applied to fastened members that have a standard female threaded portion. In addition, since the sleeve portion and the nut portion are molded as one unit, the number of parts is reduced and it is easy to handle.

[0017] In the sixth invention, in the first or fifth invention, The outer diameter of the sleeve portion shall be 0.1 mm or more and 0.5 mm or less larger than the outer diameter of the fastening bolt.

[0018] If the outer diameter of the sleeve portion is more than 0.5 mm larger than the outer diameter of the fastening bolt, it will be difficult to insert it into the gap between the female thread portion and the sleeve portion. On the other hand, if it is less than 0.1 mm smaller, it will be difficult to insert it into the fastening bolt. However, with the above configuration, the sleeve portion can easily fit between the male thread portion and the female thread portion of the fastening bolt, and it can also be molded.

[0019] In the seventh invention, in any one of the first, fifth, and sixth inventions, The thickness of the sleeve portion is 0.1 mm or more and 0.2 mm or less.

[0020] If the sleeve is thicker than 0.2 mm, it is too thick and difficult to fit into the gap between it and the female threaded portion. On the other hand, if it is thinner than 0.1 mm, it is too thin and difficult to mold. However, with the above configuration, it is easy to fit between the male threaded portion of the fastening bolt and the female threaded portion, and it is also possible to mold it.

[0021] In the eighth invention, in any one of the first and fifth to seventh inventions, The height of the sleeve portion is 5 mm or more.

[0022] When the height of the sleeve portion is 5 mm or more, the sleeve portion is sufficiently engaged between the male screw portion and the female screw portion, and the anti-loosening effect is effectively exerted.

[0023] In the fastening method of the ninth anti-loosening sleeve, a fastening bolt, an anti-loosening sleeve having an annular flange portion with a through-hole through which the fastening bolt is inserted and a cylindrical sleeve portion extending axially from the flange portion, a washer having a through-hole through which the anti-loosening sleeve is inserted and sandwiched between the fastened member and the bolt head or nut of the fastening bolt are prepared, After inserting the fastening bolt into the anti-loosening sleeve, with the washer passed through from the tip side of the anti-loosening sleeve, the tip of the fastening bolt is inserted into the bolt insertion hole so that the axial end face of the washer abuts against the periphery of the bolt insertion hole of the fastened member, or The fastening bolt is inserted into the bolt insertion hole of the fastened member, the anti-loosening sleeve is inserted through the tip of the fastening bolt protruding from the periphery of the bolt insertion hole, then the washer is inserted, and the axial end face of the washer is made to abut against the periphery of the bolt insertion hole of the fastened member, Thereafter, with the anti-loosening sleeve sandwiched between the outer periphery of the male screw portion of the fastening bolt and the female screw portion of the inner periphery of the bolt insertion hole of the fastened member or the female screw portion of the nut inserted from the tip of the fastening bolt, the male screw portion is tightened to the female screw portion.

[0024] According to the above configuration, the cylindrical sleeve portion is tightened while sandwiched between the outer circumference of the male threaded portion of the fastening bolt and the female threaded portion of the inner circumference of the bolt insertion hole of the fastened member or the female threaded portion of the nut, so that the male and female threaded portions are in close contact and the fastening bolt does not loosen. Furthermore, it is only necessary to tighten the sleeve portion with the male and female threaded portions, eliminating the need for a special nut, and it can also be applied to fastened members that have a general-purpose female threaded portion. The axial end faces of the nut or washer may contact the periphery of the bolt insertion hole of the fastened member via another general-purpose washer, or they may contact it directly.

[0025] In the tenth method of fastening the anti-loosening sleeve, Fastening bolts and Prepare an annular washer portion having a through hole through which the fastening bolt is inserted, and a loosening prevention sleeve comprising a sleeve portion that extends integrally in the axial direction from the washer portion. Insert the fastening bolt into the sleeve portion, and insert the tip of the fastening bolt into the bolt insertion hole so that the axial end face of the washer portion abuts against the periphery of the bolt insertion hole of the member to be fastened, or Insert the fastening bolt through the bolt insertion hole of the member to be fastened, insert the anti-loosening sleeve so that the sleeve portion protrudes axially from the tip of the fastening bolt protruding from the periphery of the bolt insertion hole, and bring the axial end face of the washer portion into contact with the periphery of the bolt insertion hole of the member to be fastened. Subsequently, the sleeve portion is sandwiched between the outer circumference of the male threaded portion of the fastening bolt and the female threaded portion of the inner circumference of the bolt insertion hole of the fastened member, or the female threaded portion of the nut inserted from the tip of the fastening bolt, and the male threaded portion is tightened to the female threaded portion.

[0026] According to the above configuration, the cylindrical sleeve portion is tightened while sandwiched between the outer circumference of the male thread portion of the fastening bolt and the female thread portion of the inner circumference of the bolt insertion hole of the fastened member or the female thread portion of the nut, so that the male and female thread portions are in close contact and the fastening bolt does not loosen. Furthermore, it is only necessary to tighten the sleeve portion with the male and female thread portions, eliminating the need for a special nut, and it can also be applied to fastened members that have a general-purpose female thread portion. Since the sleeve portion and the nut portion are molded as one piece, the number of parts is reduced and it is easy to handle. The axial end faces of the nut and washer portions may contact the periphery of the bolt insertion hole of the fastened member via another general-purpose washer, or they may contact directly. [Effects of the Invention]

[0027] As described above, the present invention makes it possible to achieve a loosening prevention effect with a simple configuration. [Brief explanation of the drawing]

[0028] [Figure 1A] This is a cross-sectional view showing a fastening structure to which a loosening prevention sleeve according to Embodiment 1 of the present invention is fastened. [Figure 1B] This is an exploded view of a fastening structure to which a loosening prevention sleeve according to Embodiment 1 of the present invention is fastened. [Figure 2] The image shows an anti-loosening sleeve according to Embodiment 1 of the present invention, where (a) is a plan view and (b) is a front view. [Figure 3] The image shows a washer according to Embodiment 1 of the present invention, where (a) is a cross-sectional view and (b) is a bottom view. [Figure 4A] This is a cross-sectional view showing a fastening structure to which a loosening prevention sleeve according to a modified embodiment of the present invention is fastened. [Figure 4B] This is an exploded view of a fastening structure to which a loosening prevention sleeve according to a modified embodiment 1 of the present invention is fastened. [Figure 5] This is a cross-sectional view showing a fastening structure to which a loosening prevention sleeve according to Embodiment 2 of the present invention is fastened. [Figure 6]The image shows a loosening prevention sleeve according to Embodiment 2 of the present invention, where (a) is a plan view and (b) is a front view. [Figure 7] The image shows a washer related to an anti-loosening sleeve according to Embodiment 2 of the present invention, where (a) is a cross-sectional view and (b) is a plan view. [Figure 8] This is a cross-sectional view showing a fastening structure to which a loosening prevention sleeve according to Embodiment 3 of the present invention is fastened. [Modes for carrying out the invention]

[0029] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0030] (Embodiment 1) -Configuration of the anti-loosening sleeve- Figures 1A and 1B show a fastening structure in which a loosening prevention sleeve 2 and an annular washer 3 are fastened together according to Embodiment 1 of the present invention. For example, the loosening prevention sleeve 2 and the annular washer 3 are made of molded resin.

[0031] As shown in Figure 2, the cylindrical portion of the anti-loosening sleeve 2 in the assembled state is inserted through the washer 3 and protrudes in the axial direction. In this embodiment, the anti-loosening sleeve 2 is sandwiched between the outer circumference of the male threaded portion 10b of the fastening bolt 10 and the female threaded portion 11a of the nut 11 and tightened.

[0032] As shown in Figure 3, the annular washer 3 has a through hole 3a through which the anti-loosening sleeve 2 and the fastening bolt 10 are inserted, and in this embodiment, it is sandwiched between the bottom surface of the nut 11 and the periphery 12b of the bolt insertion hole of the fastened member 12.

[0033] As shown in Figure 2, the anti-loosening sleeve 2 has a cylindrical sleeve body 2a and a flange portion 2b that is thinner and has a smaller outer diameter than the washer 3. The material of the anti-loosening sleeve 2 is not particularly limited and can be resin, metal, paper, rubber, elastomer resin, etc. If it is made of resin, polypropylene, nylon 66, ABS resin, etc. can be considered, but in this embodiment, it is made of polypropylene resin due to its moldability and ability to engage with the female screw portion 11a.

[0034] The sleeve body 2a is thin-walled cylindrical in shape, its inner diameter is the same as or slightly larger than the maximum diameter of the male threaded portion 10b of the corresponding fastening bolt 10, and its outer diameter is 0.1 mm to 0.5 mm larger than the outer diameter of the fastening bolt 10. In this embodiment, the outer diameter is 0.1 mm larger than the outer diameter of the fastening bolt 10. The thickness of the sleeve body 2a is 0.1 mm to 0.2 mm, and 0.1 mm to 0.15 mm is more desirable. The height of the sleeve body 2a is preferably 5 mm or more, but in that case, it is sufficient that the lowest part at the tip of the sleeve body 2a is 5 mm or more, and the tip of the sleeve body 2a does not need to be formed at the same height on a plane perpendicular to the axial direction, and may be inclined or have some irregularities.

[0035] The flange portion 2b is configured to be sandwiched between the washer 3 and the nut 11. In this embodiment, the flange portion 2b is fitted into a circular groove portion 3b recessed in the inner circumference of the washer 3. The inner diameter of the circular groove portion 3b is slightly larger than the outer diameter of the flange portion 2b, and its depth is slightly greater than the thickness of the flange portion 2b. The thickness of the flange portion 2b is preferably 1.0 mm or more from the standpoint of moldability. The outer diameter of the flange portion 2b is preferably 5 mm or more larger than the inner diameter from the standpoint of rigidity and other factors. However, the thickness of the circular groove portion 3b may be shallower than the thickness of the flange portion 2b, and the flange portion 2b may be partially housed in the circular groove portion 3b and protrude from the washer 3.

[0036] The outer and inner diameters of washer 3 may be similar to those of general-purpose washers. Since a rounded edge (R) is generally formed at the corner 2c between the sleeve body 2a and the flange portion 2b during molding, it is desirable that the washer 3 has an inner diameter large enough to avoid interference with this rounded edge. The material of washer 3 is not particularly limited, but in the case of synthetic resin, it is preferable that it be fiber-reinforced plastic (FRP). The type, length, and thickness of the added fibers are not particularly limited and general glass fibers may be used.

[0037] -Method for fastening the anti-loosening sleeve 2- Next, a method for tightening the anti-loosening sleeve 2 according to this embodiment will be described.

[0038] First, prepare the fastening bolt 10, nut 11, and the aforementioned anti-loosening sleeve 2 and washer 3. In this embodiment, a general-purpose washer 13 made of FRP is also prepared to match the material of the fastened member 12, but the general-purpose washer 13 is optional.

[0039] First, as shown in Figure 1B, a general-purpose washer 13 is fitted onto the fastening bolt 10. As mentioned above, the general-purpose washer 13 is not necessary when the rigidity of the fastened member 12 is relatively high.

[0040] Next, the fastening bolt 10 fitted with the general-purpose washer 13 is passed through the bolt insertion hole 12a of the fastened member 12, with the tip protruding beyond the fastened member 12. In this case, the bolt insertion hole 12a is a drilled hole without a female thread portion.

[0041] Next, the anti-loosening sleeve 2 is inserted from the tip of the fastening bolt 10, and then the washer 3 is inserted around the outer circumference of the anti-loosening sleeve 2. At this time, the flange portion 2b is housed in the circular groove portion 3b, and in this state, the axial end face 3c of the washer 3 abuts against the periphery 12b of the bolt insertion hole of the fastened member 12.

[0042] Subsequently, the nut 11 is inserted from the tip of the fastening bolt 10, and when the female threaded portion 11a reaches the sleeve body 2a, it is screwed in while gripping the sleeve body 2a. Then, with the sleeve body 2a sandwiched between the female threaded portion 11a of the nut 11, the male threaded portion 10b is tightened onto the female threaded portion 11a until there is no gap between the nut 11 and the washer 3. At this time, it is advisable to insert the anti-loosening sleeve 2 and washer 3 deep into the bolt insertion hole 12a of the fastened member 12 beforehand until there is no gap.

[0043] Furthermore, weather-resistant paint may be applied to each component after fastening the fastening bolts 10. In this embodiment, since the anti-loosening sleeve 2 is not visible externally, it is not necessary to apply weather-resistant paint to the anti-loosening sleeve 2.

[0044] As described above, in this embodiment, the cylindrical sleeve body 2a is tightened while sandwiched between the outer circumference of the male threaded portion 10b of the fastening bolt 10 and the female threaded portion 11a of the nut 11, so that the male threaded portion 10b and the female threaded portion 11a are in close contact and the fastening bolt 10 does not loosen.

[0045] Furthermore, since the part that the sleeve body 2a engages with only needs to have a standard-shaped male threaded portion 10b and a female threaded portion 11a, a special nut 11 is not required, resulting in a simple anti-loosening structure.

[0046] In this embodiment, since the anti-loosening sleeve 2 and the washer 3 are separate parts, the anti-loosening sleeve 2, which includes the thin flange portion 2b, and the washer 3 can be molded separately, making them easier to manufacture. Furthermore, the material of the exposed washer 3 can be made of a material with high weather resistance, while the material of the anti-loosening sleeve 2, which has the flange portion 2b covered by the washer 3, can be selected prioritizing anti-loosening effect over weather resistance.

[0047] In this embodiment, the anti-loosening sleeve 2 is made of molded resin, which makes it easier to mold even complex shapes and reduces mass compared to the case of metal. Since the fastening structure of this embodiment does not use a spring structure or a restoring force of the members, it is not a problem to use resin such as FRP, which generally has poor elasticity.

[0048] Furthermore, if the outer diameter of the sleeve body 2a is more than 0.5 mm larger than the outer diameter of the fastening bolt 10, it is difficult to insert it into the gap with the female thread portion 11a, and if it is less than 0.1 mm smaller, it is difficult to insert it into the male thread portion. However, in this embodiment, the outer diameter of the sleeve body 2a is configured to be 0.1 mm or more and 0.5 mm or less larger than the outer diameter of the fastening bolt 10, so it is easy to insert it between the male thread portion 10b and the female thread portion 11a of the fastening bolt 10, and it is also possible to mold it.

[0049] Furthermore, if the thickness of the sleeve body 2a is greater than 0.2 mm, it is too thick and difficult to fit into the gap with the female thread portion 11a, and if it is less than 0.1 mm, it is too thin and difficult to mold. However, in this embodiment, the thickness of the sleeve body 2a is set to 0.1 mm or more and 0.2 mm or less, so that it can easily fit between the male thread portion 10b and the female thread portion 11a of the fastening bolt 10 and can be molded.

[0050] Furthermore, in this embodiment, since the height of the sleeve body 2a is set to 5 mm or more, the sleeve body 2a engages sufficiently between the male threaded portion 10b and the female threaded portion 11a, and the anti-loosening effect is effectively exerted.

[0051] Therefore, according to the anti-loosening sleeve 2 of this embodiment, it is possible to achieve an anti-loosening effect with a simple configuration without using a special nut 11.

[0052] -Variations- Figures 4A and 4B show modified examples of embodiments of the present invention, differing from the above embodiment in that the female threaded portion into which the anti-loosening sleeve 2 is screwed is provided in the bolt insertion hole 12a' of the fastened member 12', rather than in the nut 11. In the following modified examples and embodiments, the same reference numerals are used for parts that are the same as those in Figures 1A to 3, and their detailed descriptions are omitted.

[0053] In this modified example, as shown in Figure 4A, a female threaded portion is formed in the bolt insertion hole 12a' of the fastened member 12', and the male threaded portion 10b of the fastening bolt 10 is screwed into this female threaded portion. Unlike the above embodiment, the bolt insertion hole 12a' does not have to be a through hole.

[0054] -Method for fastening anti-loosening sleeves- Next, the method for tightening the anti-loosening sleeve 2 according to this modified example will be described.

[0055] First, prepare the fastening bolt 10 and the anti-loosening sleeve 2 described above, similar to the embodiment described above. However, in this embodiment, the nut 11 is not used.

[0056] First, as shown in Figure 4B, the anti-loosening sleeve 2 is inserted from the tip of the fastening bolt 10, and then the washer 3 is inserted around the outer circumference of the anti-loosening sleeve 2. At this time, the flange portion 2b is housed in the circular groove portion 3b, and in this state, the axial end face 3c of the washer 3 abuts against the periphery 12b' of the bolt insertion hole of the fastened member 12'.

[0057] Next, the fastening bolt 10, into which the anti-loosening sleeve 2 is fitted, is tightened into the female thread portion of the bolt insertion hole 12a' of the member to be fastened 12'.

[0058] As a result, the washer 3 is sandwiched between the bolt head 10a of the fastening bolt 10 and the periphery 12b' of the bolt insertion hole of the fastened member 12'.

[0059] In this modified example, the cylindrical anti-loosening sleeve 2 is tightened while sandwiched between the outer circumference of the male threaded portion 10b of the fastening bolt 10 and the female threaded portion 11a on the inner circumference of the bolt insertion hole 12a' of the fastened member 12'. As a result, the male threaded portion 10b and the female threaded portion 11a are in close contact, and the fastening bolt 10 does not loosen.

[0060] Furthermore, since only a male threaded portion 10b and a female threaded portion 11a are required, a special nut 11 is not necessary, and it can also be applied to fastened members 12' that have a general female threaded portion 11a.

[0061] (Embodiment 2) Figures 5 to 7 show an anti-loosening sleeve 102 according to Embodiment 2 of the present invention. The washer 103 has a through hole 103a, similar to Embodiment 1, but differs from Embodiment 1 in that it does not have a circular groove 3b.

[0062] As shown in Figure 6, the anti-loosening sleeve 102 of this embodiment has a sleeve body 102a, similar to Embodiment 1, but has a flange portion 102b that is thinner than the thickness of the washer 103 and has an outer diameter equal to or smaller than the outer diameter of the washer 103, in the portion that covers the axial end face 103c (lower end face in Figure 5) of the washer 103. A larger outer diameter than the washer 103 is undesirable because it would make it more susceptible to direct sunlight and outside air. The corner portion 102c has a radius formed during molding, similar to Embodiment 1.

[0063] Regarding the thickness of the flange portion 102b, a thinner flange portion is preferable as it reduces the area exposed to the outside air and is less susceptible to deterioration from direct sunlight. For example, 0.2 mm is suitable. However, a thickness of 1 mm or more may be used from the standpoint of moldability.

[0064] In this embodiment as well, the thin flange portion 102b and the washer 103 can be molded separately, and the material of the exposed washer 103 can be made of a material with high weather resistance, and the material of the anti-loosening sleeve 102, which has a flange portion 102b whose axial end face is covered by the washer 103, can be selected prioritizing the anti-loosening effect over weather resistance.

[0065] Furthermore, since there is no need to provide a circular groove 3b in the washer 103 itself, it is advantageous that a general-purpose washer 13 such as FRP can be used as the washer 103 having a through hole 103a.

[0066] As described above, in this embodiment as well, it is possible to achieve a loosening prevention effect with a simple configuration without using a special nut 11.

[0067] (Embodiment 3) -Configuration of the anti-loosening sleeve- Figure 8 shows an anti-loosening sleeve 202 according to Embodiment 3 of the present invention, which differs from Embodiment 1 in that the sleeve portion 202a and the washer portion 203 are integrated.

[0068] Although not shown in detail, in this embodiment as well, similar to the modification in Embodiment 1, the male threaded portion 10b may be screwed into the female threaded portion of the bolt insertion hole 12a' of the fastened member 12' without using a nut 11.

[0069] In this embodiment as well, the anti-loosening sleeve 202 has a through hole 203a through which the fastening bolt 10 is inserted, and an annular washer portion 203 that is sandwiched between the bolt head 10a or nut 11 of the fastening bolt 10 and the fastened member 12'.

[0070] -Method for fastening anti-loosening sleeves- Next, a method for tightening the anti-loosening sleeve 202 according to this embodiment will be described.

[0071] First, prepare the nut 11 and the locking sleeve 202.

[0072] Next, the general-purpose washer 13 is fitted onto the fastening bolt 10. However, as in Embodiment 1, the general-purpose washer 13 is not necessary if the rigidity of the fastened member 12 is relatively high.

[0073] Next, the fastening bolt 10 fitted with the general-purpose washer 13 is passed through the bolt insertion hole 12a of the fastened member 12, with its tip protruding beyond the fastened member 12.

[0074] Next, the anti-loosening sleeve 202, which is an integrated washer portion 203 and sleeve portion 202a, is inserted from the tip of the fastening bolt 10, and the axial end face 203c of the washer portion 203 comes into contact with the periphery 12b of the bolt insertion hole of the fastened member 12.

[0075] Next, the nut 11 is inserted from the tip of the fastening bolt 10, and the sleeve portion 202a is sandwiched between the female thread portion 11a of the nut 11. Then, the male thread portion 10b is tightened onto the female thread portion 11a, and when the female thread portion 11a reaches the sleeve portion 202a, the fastening bolt 10 is screwed in while gripping the sleeve portion 202a until there is no gap between the nut 11 and the washer 3.

[0076] Thus, in this embodiment as well, the cylindrical sleeve portion 202a is tightened while sandwiched between the outer circumference of the male threaded portion 10b of the fastening bolt 10 and the female threaded portion 11a of the nut 11, so that the male threaded portion 10b and the female threaded portion 11a are in close contact and the fastening bolt 10 does not loosen.

[0077] Furthermore, since only a male threaded portion 10b and a female threaded portion 11a are required, a special nut 11 is not necessary, and as shown in the modified example of Embodiment 1 above, it can also be applied to fastened members 12' that have a general female threaded portion 11a.

[0078] Furthermore, since the sleeve portion 202a and the nut portion 11 are molded together, the number of parts is reduced and it is easier to handle.

[0079] As described above, in this embodiment as well, it is possible to achieve a loosening prevention effect with a simple configuration without using a special nut 11.

[0080] The embodiments described above are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or uses. [Explanation of symbols]

[0081] 2. Anti-loosening sleeve 2a Sleeve body (sleeve part) 2b Flange section 2c Corner 3 washers 3a Through hole 3b Circular groove 3c Axial end face 10 Fastening bolts 10a Bolt head 10b Male threaded section 11 nuts 11a Female threaded section 12,12' Parts to be fastened 12a, 12a' Bolt insertion holes 12b, 12b' Periphery of bolt insertion hole 13 General-purpose washers 102 Anti-loosening sleeve 102a Sleeve body (sleeve part) 102b Flange section 103 Washer 103a Through hole 103c Axial end face 202 Anti-loosening sleeve 202a Sleeve section 203 Washer section 203a Through hole 203c Axial end face

Claims

1. It comprises an annular flange portion having a through hole through which a fastening bolt is inserted, and a cylindrical sleeve portion extending axially from the flange portion, which is sandwiched and tightened between the outer circumference of the male threaded portion of the fastening bolt and the inner circumference of the bolt insertion hole of the fastened member or the female threaded portion of the nut, The inner diameter of the sleeve portion is greater than or equal to the maximum outer diameter of the male screw portion. A loosening prevention sleeve characterized by the following features.

2. A locking sleeve having an annular flange portion with a through hole through which a fastening bolt is inserted, and a cylindrical sleeve portion extending axially from the flange portion, A fastening structure in which the fastened member is fastened by an annular washer having a through hole through which the sleeve portion is inserted and sandwiched between the fastened member and the bolt head or nut of the fastening bolt, The fastened member is tightened with the sleeve portion sandwiched between the outer circumference of the male threaded portion of the fastening bolt and the inner circumference of the bolt insertion hole of the fastened member or the female threaded portion of the nut. The flange portion is thinner than the washer, has a smaller outer diameter than the washer, and is fitted into a circular groove recessed on the inner circumference of the through hole of the washer. A fastening structure characterized by the following features.

3. It has a through hole through which a fastening bolt is inserted, and an annular washer portion that is sandwiched between the fastened member and the bolt head or nut of the fastening bolt, It comprises a cylindrical sleeve portion that extends integrally from the washer portion in the axial direction and is sandwiched and tightened between the outer circumference of the male threaded portion of the fastening bolt and the inner circumference of the bolt insertion hole of the fastened member or the female threaded portion of the nut, The inner diameter of the sleeve portion is greater than or equal to the maximum outer diameter of the male screw portion. A loosening prevention sleeve characterized by the following features.

4. The outer diameter of the sleeve portion is 0.1 mm to 0.5 mm larger than the outer diameter of the fastening bolt. A loosening prevention sleeve according to feature 1 or 3.

5. The thickness of the sleeve portion is 0.1 mm or more and 0.2 mm or less. The anti-loosening sleeve according to feature 1 or 3.

6. The height of the sleeve portion is 5 mm or more. The anti-loosening sleeve according to feature 1 or 3.

7. Fastening bolts and A locking sleeve having an annular flange portion with a through hole through which a fastening bolt is inserted, and a cylindrical sleeve portion extending axially from the flange portion, Prepare an annular washer having a through hole through which the anti-loosening sleeve is inserted, and which is sandwiched between the fastened member and the bolt head or nut of the fastening bolt. After inserting the fastening bolt into the anti-loosening sleeve, the washer is passed through the tip of the anti-loosening sleeve, and the tip of the fastening bolt is inserted into the bolt insertion hole so that the axial end face of the washer abuts against the periphery of the bolt insertion hole of the member to be fastened, or Insert the fastening bolt through the bolt insertion hole of the member to be fastened, insert the anti-loosening sleeve onto the tip of the fastening bolt protruding from the periphery of the bolt insertion hole, then insert the washer, and bring the axial end face of the washer into contact with the periphery of the bolt insertion hole of the member to be fastened. Subsequently, with the anti-loosening sleeve sandwiched between the outer circumference of the male threaded portion of the fastening bolt and the female threaded portion of the inner circumference of the bolt insertion hole of the fastened member or the female threaded portion of the nut inserted from the tip of the fastening bolt, the male threaded portion is tightened to the female threaded portion. A method for fastening a loosening prevention sleeve, characterized by the following features.

8. Fastening bolts and Prepare an annular washer portion having a through hole through which the fastening bolt is inserted, and a loosening prevention sleeve comprising a sleeve portion that extends integrally in the axial direction from the washer portion. Insert the fastening bolt into the sleeve portion, and insert the tip of the fastening bolt into the bolt insertion hole so that the axial end face of the washer portion abuts against the periphery of the bolt insertion hole of the member to be fastened, or Insert the fastening bolt through the bolt insertion hole of the member to be fastened, insert the anti-loosening sleeve so that the sleeve portion protrudes axially from the tip of the fastening bolt protruding from the periphery of the bolt insertion hole, and bring the axial end face of the washer portion into contact with the periphery of the bolt insertion hole of the member to be fastened. Subsequently, with the sleeve portion sandwiched between the outer circumference of the male threaded portion of the fastening bolt and the female threaded portion of the inner circumference of the bolt insertion hole of the fastened member or the female threaded portion of the nut inserted from the tip of the fastening bolt, the male threaded portion is tightened into the female threaded portion. A method for fastening a loosening prevention sleeve, characterized by the following features.

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