Nut

Abstract

To provide a nut capable of preventing loosening by only being fastened to a bolt.SOLUTION: A nut is composed of a nut body 4, a plurality of nut segments 2, each having a female thread part, which screws into a male thread part of a bolt, formed on an inner side thereof, and a connecting member 8 that connects upper end part regions of the plurality of nut segments. An inner peripheral surface of a nut segment housing part 3 is at least partially formed in an inclined surface shape, an outer peripheral surface of each nut segment is formed in an inclined surface shape having substantially the same angle as that of the nut segment housing part, and an outer peripheral part of the nut segment abuts against and is supported by the inclined-shaped inner peripheral surface of the nut segment housing part. The connecting member is formed of a material having elasticity, and due to repulsive force, the outer peripheral surface region of the upper end part of the nut segment comes into close contact with the nut segment housing part. With the bolt tightened, the nut segment moves downward, and the inner peripheral surface of the nut segment housing part and the outer peripheral surface of the nut segment fit together.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a nut having a plurality of nut segments. [Background technology]

[0002] Conventionally, a nut using nut segments has been known, which is "a nut comprising: a nut body having an outer wall formed in a polygonal shape and having inclined holes in the inner wall with successively smaller diameters; a stopper piece having a bolt insertion hole formed at the end of the large-diameter side of the nut body; at least three or more guide pieces formed in the axial direction of the inner wall surface of the nut body; at least three or more nut segments having threads formed on the inner wall surface to be threadedly engaged with a bolt and attached so as to be slidable in the axial direction between the guide pieces; a flange-shaped attachment piece fixed to the end of the small-diameter side of the nut body to prevent the at least three or more nut segments from coming off and protruding outward from the outer circumferential surface of the nut body; and a biasing spring housed within the nut body so as to constantly bias the at least three or more nut segments toward the small-diameter side of the nut body" (Patent Document 1).

[0003] However, although this nut can be easily tightened, in order to achieve the same anti-loosening effect as a so-called double nut, another nut must be used, and the anti-loosening effect cannot be easily achieved. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-072110 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above-mentioned drawbacks of the conventional art, the present invention has an object to provide a nut that can prevent loosening by simply fastening one nut to a bolt.

[0006] The above and other objects and novel features of the present invention will become more fully apparent from the following description read in conjunction with the accompanying drawings.

[0007] However, the drawings are for illustrative purposes only and do not limit the technical scope of the present invention. [Means for solving the problem]

[0008] In order to achieve the above object, the nut of the present invention described in claim 1 is composed of a nut body having a plurality of nut segment storage portions, a plurality of nut segments each having a female thread portion formed on the inside that screws into the male thread portion of a bolt, and stored in the plurality of nut segment storage portions, and a connecting member that connects the upper end portions of the plurality of nut segments, and at least a portion of the inner circumferential surface of the nut segment storage portion is formed as an inclined surface, and the outer circumferential surface of the nut segment is formed as an inclined surface at approximately the same angle as the nut segment storage portion, and when the nut segment is stored in the nut segment storage portion, the outer circumferential surface of the nut segment is supported by abutting against the inclined inner circumferential surface of the nut segment storage portion, and the connecting member is formed of a material having elasticity, and when the nut segment is stored in the nut segment storage portion, the outer circumferential surface near the upper end of the nut segment is tightly attached to the nut segment storage portion due to a repulsive force, and when the bolt is tightened, the nut segment moves downward, and the inner circumferential surface of the nut segment storage portion and the outer circumferential surface of the nut segment fit together. The nut according to claim 2 is characterized in that, when the male thread portion and the female thread portion are fastened, the upper end portion of the nut segment storage portion is formed to be positioned higher than the vicinity of the upper end portion of the nut segment. The nut according to claim 3 is characterized in that it further comprises a lid above the nut segment storage portion for preventing the nut segments from dropping out of the nut segment storage portion. [Effects of the Invention]

[0009] As is clear from the above description, the present invention provides the following effects. (1) In each invention described in claim 1, by tightening the bolt, the nut segment moves downward, and the inner surface of the nut segment storage section and the outer surface of the nut segment are fitted together. Therefore, by tightening the bolt and the nut, the threads of the female thread portion and the male thread portion of the bolt can be tightly fitted together (no clearance is generated). This provides a so-called double nut-like effect of preventing loosening. (2) When the nut segment is inserted into the nut segment storage section, the repulsive force of the connecting member causes the outer peripheral surface near the upper end of the nut segment to adhere more closely to the nut segment storage section, thereby preventing the nut segment from falling out of the nut segment storage section. Therefore, the effect of preventing loosening can be more reliably obtained continuously. (3) The invention described in claim 2 also has the same effects as those described in (1) and (2), and when the inner surface of the nut segment storage section and the outer surface of the nut segment are fitted together, the repulsive force of the connecting member can more strongly maintain the fitted state. (4) When the bolt and the nut are tightened, the repulsive force of the connecting member presses the vicinity of the upper end of the nut segment more strongly against the inner peripheral surface of the nut segment storage portion. Therefore, the nut segment can be more reliably prevented from falling off from the nut segment storage section, and when the inner surface of the nut segment storage section and the outer surface of the nut segment are engaged with each other, the repulsive force of the connecting member can more firmly maintain the engaged state. (5) In the invention described in claim 3, the same effects as those of the above (1) to (4) can be obtained, and the nut segments can be more reliably prevented from falling out of the nut segment storage portion. [Brief explanation of the drawings]

[0010] 1 to 7 are explanatory diagrams showing a first embodiment of the present invention. 8 and 9 are explanatory diagrams showing a second embodiment of the present invention. [Figure 1] FIG. 2 is a plan view of the nut according to the first embodiment. [Figure 2] Cross-sectional view of line 2-2 in Figure 1. [Figure 3] FIG. 10 is an explanatory diagram of a nut segment. [Figure 4] Cross-sectional view taken along line 4-4 in Figure 3. [Figure 5] FIG. [Figure 6] Cross-sectional view taken along line 6-6 in Figure 5. [Figure 7] FIG. 10 is an explanatory diagram showing the state in which the bolts are tightened. [Figure 8] FIG. 10 is a plan view of a nut according to a second embodiment. [Figure 9] Cross-sectional view taken along line 9-9 in Figure 8. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below with reference to the embodiments shown in the drawings, in which the vertical direction refers to the vertical direction in FIG.

[0012] In a first embodiment of the present invention shown in FIGS. 1 to 7, reference numeral 1 denotes a nut having a plurality of nut segments 2 that slide in a direction in which the inner diameter increases.

[0013] As shown in Figures 1 and 2, this nut 1 is composed of a nut body 4 having a plurality of nut segment storage sections 3, a plurality of nut segments 2 each having a female thread section 7 formed on the inside to thread onto a male thread section 6 of a bolt 5, each stored in the plurality of nut segment storage sections 3, and a connecting member 8 connecting the upper ends of the plurality of nut segments 2.

[0014] 3 and 4, the nut segment 2 is formed in a substantially semicircular shape in a plan view, and its outer peripheral surface 2a is formed as an inclined surface that slopes in a direction in which the diameter decreases from top to bottom. The outer peripheral surface 2a of the nut segment 2 is formed so as to have substantially the same angle as the inclined surface 9 of the nut segment storage section 3 described later.

[0015] A thin plate-like connecting member 8 is provided at the upper end of the nut segment 2, and both ends of a plurality of nut segments 2, two in this embodiment, are connected by this connecting member 8.

[0016] The connecting member 8 is made of an elastic material, and in this embodiment, it is made of the same material as the nut segments 2, formed into a thin plate shape, and is formed to have elasticity similar to that of a leaf spring material. Note that in this embodiment, it is formed integrally with the nut segments 2, but it may be formed of a different material and fixed to connect the nut segments 2. Also, in this embodiment, it is formed into a thin plate shape, but it may also be formed into a wire-like, spring-like shape, or other shape. Furthermore, not only metals such as iron, but also high-strength plastics and the like having elasticity can be used as the connecting member 8.

[0017] When three or more nut segments 2 are used, it is preferable to connect the upper ends of adjacent nut segments 2 with a connecting member 8.

[0018] In this embodiment, the nut body 4 is made of metal and is formed so that a bolt can pass through it. As shown in Figures 5 and 6, it has a hexagonal shape in plan view, and inside it are formed two nut segment storage sections 3 separated by a total of two partition walls 3a at a predetermined interval in the circumferential direction. Note that the nut body 4 may be formed of a material such as resin, and three or more nut segment storage sections 3 may be formed, and the shape of the nut body 4 may be a substantially polygonal shape, a circle, or the like in plan view. Furthermore, the partition walls 3a of the nut segment storage sections 3 are formed to be sized so as not to come into contact with the connecting member 8.

[0019] The inner peripheral surface of this nut segment storage section 3 is formed into an inclined surface 9 that slopes in a direction in which the diameter decreases from top to bottom when viewed in cross section, and a nut segment 2 is stored in each of the two nut segment storage sections 3.

[0020] In this embodiment, the nut segment storage section 3 is formed with an inclined surface from the upper end to the lower end of the nut body, but when the nut segment 2 is stored, the outer surface 2a of the nut segment 2 abuts and is supported against the inclined inner surface (inclined surface 9) of the nut segment storage section 3, and it is only necessary that the shape be such that it is in an engaged state when the bolt 5 is tightened, and only a portion of it may be made into an inclined surface 9.

[0021] The central portion of the nut segment storage portion 3 is a bolt through-hole through which the bolt 5 can pass.

[0022] When the nut segment 2 is inserted and stored in this nut segment storage portion 3, the outer peripheral surface 2a of the nut segment 2 moves downward along the inclined surface 9, and the inner peripheral surface (inclined surface 9) of the nut segment storage portion 3 and the outer peripheral surface 2a of the nut segment 2 come into contact and are supported at a predetermined position by the inclined surface 9. In other words, this nut segment storage portion 3 does not support the bottom of the nut segment 2 at its bottom, but supports the nut segment 2 by the outer peripheral surface of the nut segment 2 coming into contact with the inclined surface 9 of the nut segment storage portion 3. Therefore, even if a straight portion or a bottom portion other than the inclined surface 9 is formed below the nut segment storage portion 3, it is sufficient as long as the outer peripheral surface of the nut segment 2 comes into contact with the inclined surface 9 of the nut segment storage portion 3 to support the nut segment 2.

[0023] When the nut segment 2 is stored in the nut segment storage section 3 in this manner, the repulsive force of the connecting member 8 presses the outer surface near the upper end of the nut segment 2 against the inclined surface 9 of the nut segment storage section 3, thereby providing a tighter fit and acting as a fall-off prevention means that prevents the nut segment 2 from falling off with a light force.

[0024] However, this connecting member 8 can provide a certain degree of prevention of falling off as long as it is connected until the nut segment 2 is stored in the nut segment storage section 3 (when the inner surface (inclined surface 9) of the nut segment storage section 3 and the outer surface 2a of the nut segment 2 are in contact), so once the loosely fitted state is reached, the connecting member 8 breaks and the nut segments 2 become separable, so there is no problem.

[0025] When using the nut 1 of the present invention, the bolt 5 is inserted from below the nut body 4, and with the bolt 5 in contact with the female thread portion 7 of the nut segment 2, the bolt 5 or the nut 1 is rotated in the direction of tightening. The elastic force of the connecting member 8 causes the outer peripheral surface near the upper end of the nut segment 2 to adhere tightly to the nut segment storage portion 3, so the male thread portion 6 of the bolt 5 and the female thread portion 7 of the nut segment 2 thread together without spinning freely or sliding upward.

[0026] When the head of the bolt 5 or the bottom of the nut 1 comes into contact with the object to be fastened, and the nut 1 or bolt 5 does not move up or down even when tightened, further tightening will move the nut segment 2 downward so that it is pressed into the nut segment storage section 3. In this state, as shown in Figure 7, the inclined surface 9 of the nut segment storage section 3 and the outer peripheral surface 2a of the nut segment 2 tightly fit together like a wedge, and the female thread portion 7 of the nut segment 2 and the male thread portion 6 of the bolt 5 also fit together until there is no clearance, resulting in an effect similar to that of a double nut. In other words, by tightening the bolt, the nut segment moves further downward, and the inner surface of the nut segment storage section fits into the outer surface of the nut segment, causing the threads of the female thread portion 7 of the nut segment 2 and the threads of the male thread portion 6 of the bolt 5 to fit tightly together, leaving almost no clearance, preventing the bolt 5 from rotating, and the nut segment 2 and bolt 5 becoming one unit to prevent loosening.

[0027] Furthermore, if the connecting member 8 is connected even when the bolt 5 and nut 1 are tightened, tightening the bolt 5 and nut 1 causes the clearance between the male thread portion 6 and the female thread portion 7 to become approximately 0.25 mm to 0 mm, causing them to come into close contact. This causes the stress of the inclination angle of the threads to act on the connecting member 8, which then repels this force, forcing the outer peripheral surface near the upper end of the nut segment 2 firmly against the inner peripheral surface of the nut segment storage portion 3 of the nut body 4.

[0028] This action causes the nut segment 2 to be tightly fitted into the nut segment storage section 3, preventing the nut segment 2 from falling off and more reliably preventing the screw from loosening due to vertical movement. To achieve this effect most effectively, it is desirable to form the nut segment storage section 3 so that the upper end of the nut segment 2 is located higher than the vicinity of the upper end of the nut segment 2 (the portion where the diameter is greatest) when the male thread portion 6 of the bolt 5 and the female thread portion 7 of the nut segment 2 are fastened together. The vicinity of the upper end of the nut segment 2 refers to the portion where the diameter of the nut segment 2 is greatest. For example, if the upper end is chamfered, this refers to the portion where the diameter is greatest, slightly below the upper end. Because this portion is pressed most strongly, it is desirable to form the upper end of the nut segment storage section 3 so that it is located higher than this portion.

[0029] Furthermore, even if the upper end of the nut segment storage section 3 is located lower than the upper end of the nut segment 2, the outer surface of the nut segment 2 is pressed against the inner surface of the nut segment storage section 3 due to the repulsive force of the connecting member 8, so a certain effect can be obtained.

[0030] [Different modes for carrying out the invention] Next, a different embodiment of the present invention will be described with reference to Figures 8 and 9. In describing this different embodiment, the same components as those in the first embodiment will be designated by the same reference numerals, and redundant description will be omitted.

[0031] In the second embodiment of the present invention shown in Figures 8 and 9, the main difference from the first embodiment of the present invention is that a cover body 10 is provided above the nut segment storage section 3 to prevent the nut segment 2 from falling off from the nut segment storage section 3. With such a nut 1A, the same effect as in the first embodiment of the present invention can be obtained, and the nut segment 2 can be more reliably prevented from falling off from the nut segment storage section 3.

[0032] In this embodiment, the lid body 10 is formed in a shape that can completely close the upper end of the nut segment storage section 3, i.e., the opening at the top of the nut body 4, and is fixed to the nut body 4 by adhesive or the like. The lid body 10 may be attached in an engaged state to the outer peripheral surface of the nut body 4 or the nut segment storage section 3, or may be fixedly attached by adhesive, welding, or the like.

[0033] In addition, in this embodiment, the lid body is provided with a bolt-through hole 11, but if a bolt 5 of a length that does not penetrate the lid body 10 when tightened is used, the nut body 4 may be formed into a shape that can completely block the opening at the top. Although the nut has been described as not having a washer, a washer having a screw hole or a claw may be provided, or other known washers may be used. [Industrial Applicability]

[0034] The present invention is applicable to the nut manufacturing industry. [Explanation of symbols]

[0035] 1, 1A: nut, 2: nut segment, 3: Nut segment storage section, 4: Nut body, 5: Bolt, 6: Male thread, 7: female thread portion, 8: connecting member, 9: Inclined surface, 10: Lid body, 11: Bolt hole.

[0036]

Claims

1. The nut body has a plurality of nut segment storage sections, and a plurality of nut segments each having a female thread portion formed on the inside thereof to be threaded with a male thread portion of a bolt, the nut segments being stored in the plurality of nut segment storage sections, respectively, and a connecting member connecting the vicinity of the upper end portions of the plurality of nut segments. At least a portion of the inner circumferential surface of the nut segment storage portion is formed as an inclined surface, and the outer circumferential surface of the nut segment is formed as an inclined surface at approximately the same angle as the nut segment storage portion. When the nut segment is stored in the nut segment storage portion, the outer circumferential portion of the nut segment is supported by contacting the inclined inner circumferential surface of the nut segment storage portion. The connecting member is formed of a material having elasticity, and when the nut segment is stored in the nut segment storage section, the outer peripheral surface near the upper end of the nut segment is tightly attached to the nut segment storage section due to a repulsive force, When the bolt is tightened, the nut segment moves further downward, and the inner peripheral surface of the nut segment fits into the outer peripheral surface of the nut segment.

2. The nut according to claim 1, characterized in that, when the male thread portion and the female thread portion are fastened together, the upper end portion of the nut segment storage portion is formed to be positioned higher than the vicinity of the upper end portion of the nut segment.

3. 3. The nut according to claim 1, further comprising a lid above the nut segment storage section for preventing the nut segments from falling out of the nut segment storage section.

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