JP2002235723A - Structure for preventing corotation of screw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for preventing a corotation of a screw following the process of fastening capable of preventing the corotation and loosening of the screw, preventing a corotation preventing projection from being broken and damaged, and allowing the corotation preventing projection from being satisfactorily bitten into a mating material by forming integrally a plurality of generally triangular corotation preventing projections on the lower surface of the flange of a flanged bolt or a flanged nut so that a bottom side is positioned on the lower surface and an apex angle is formed in an obtuse angle. SOLUTION: The plurality of corotation preventing projections 21 are formed integrally on the flange lower surface 16a of the flanged 16 bolt 11 or the flanged nut. The projections 21 are formed in such a generally triangular shape that the bottom side is positioned on the lower surface 16a of the flange, and the apex angle is formed in the obtuse angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing co-rotation of screws or bolts when tightening or fixing a mating member using bolts and nuts.

[0002]

2. Description of the Related Art Conventionally, for example, when two members as mating members are tightened and fixed using bolts and nuts, bolts and nuts are used.
A so-called co-rotation occurs in which one rotation of the nut moves with the other. Various inventions have conventionally been made as a structure for preventing such co-rotation, and one example is shown in FIG. 9 (see Japanese Patent Application Laid-Open No. 9-170616).

The conventional structure shown in FIG. 9 is a screw 81 such as a washer interposed between a flange seating surface of a flanged bolt and a mating member.
The lower surface (shown in the drawing) is provided with a plurality of recesses 82 and a biting projection 83 projecting from the recess 82 toward the mating member.

According to this conventional structure, there is an advantage that the above-mentioned biting projections 83 can bite into the mating material and prevent the co-rotation of the flanged bolt at the time of tightening the nut. Since the mating member 83 is formed so as to protrude at an acute angle, when the mating member is a metal member such as iron, the surface of the mating member is not only greatly damaged by the sharp-angled sticking protrusion 83, but also the mating member 83 is formed. However, there is a problem that the nut is broken or damaged when tightened with a nut.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a plurality of substantially triangular co-rotating bolts or nuts having a flange on a lower surface of a flange, the bottom surface of which is formed at the lower surface, and the apex angle of which is formed at an obtuse angle. By integrally forming the anti-rotation projection, not only can the co-rotation prevention projection be prevented from being broken or broken, but also the screws that can be satisfactorily bite into the mating material by the co-rotation prevention projection can be prevented. The purpose is to provide a co-rotation prevention structure.

[0006]

According to the present invention, there is provided a structure for preventing co-rotation of screws, wherein a plurality of co-rotation prevention protrusions are integrally formed on a lower surface of a flange of a bolt with a flange or a nut with a flange. It has a substantially triangular shape in which the bottom is located on the lower surface and the apex angle is formed at an obtuse angle.

[0007] The flanged bolt or the flanged nut having the above structure is made of a metal which is stronger than iron, that is, a strong steel.
(Ni-Cr steel, Ni-Cr-Mo steel, Cr steel, Cr-
(Mo steel, Mn steel, Mn-Cr steel) or stainless steel.

According to the above construction, when the mating member is tightened using the flanged bolt and the nut or the flanged nut and the bolt, the screws on the side having the co-rotation preventing protrusion are not rotated, and are not provided. The screws are tightened into the screw portion of the bolt or the screw hole of the nut. In this case, the co-rotation prevention protrusion cuts into the mating material, thereby preventing co-rotation and loosening. In addition, since the above-mentioned co-rotation prevention protrusion has an apex angle formed into a substantially triangular shape with an obtuse angle,
It is possible to prevent breakage and breakage of the co-rotation prevention projection while ensuring the biting property of the counterpart material.

In one embodiment of the present invention, the substantially triangular vertices of the co-rotation prevention projection are formed in a round shape. According to the above configuration, the apex of the co-rotation prevention projection is formed in a round shape, so that the mating member to be fastened is not damaged except at a portion where the projection bites.

[0010] In one embodiment of the present invention, the co-rotation prevention projection is formed in a tapered shape in which the bottom side is wide and the top side is narrow. According to the above configuration, the co-rotation prevention projection can be more easily bite into the counterpart material by the above-described tapered structure, and the tightening torque when screwing the nut can be reduced.

In one embodiment of the present invention, the co-rotation preventing projection is formed integrally with the outer peripheral portion within the lower surface of the flange. According to the above configuration, since the co-rotation prevention protrusion is located on the outer peripheral portion, the torque for preventing co-rotation increases, and the co-rotation prevention effect can be improved.

In one embodiment of the present invention, three to six co-rotation prevention protrusions are formed at equal intervals. According to the above configuration, there is no inclination of the bolt at the time of tightening, and no extra tightening force is required. In other words, if the number of co-rotation prevention protrusions is too small, the bolt tilts during tightening. Conversely, if the number of co-rotation prevention protrusions is too large, extra tightening force is required. Since the number of preventive projections is appropriately set, there is no inclination of the bolt at the time of tightening, and no extra tightening force is required. Moreover,
Since the plurality of co-rotation prevention protrusions are formed at equal intervals,
The plurality of co-rotation prevention protrusions bite into the mating material evenly.

In one embodiment of the present invention, the bolt neck portion in which the flange lower surface and the screw portion are integrated has a tapered portion having a large diameter on the flange lower surface side. According to the above configuration, by forming the above-described tapered portion, the bolt can be aligned with the bolt insertion hole (so-called bolt hole) formed in the counterpart material.
That is, the center of the bolt hole and the axis of the bolt can be matched.

In one embodiment of the present invention, a nut in which a disc spring washer is rotatably integrated with the nut body is screwed into the threaded portion of the flanged bolt.

According to the above configuration, when the mating member is tightened with the bolt and the nut, the co-rotation prevention protrusion of the bolt is pulled toward the mating member by the spring force of the disc spring washer.
It is possible to achieve both more reliable prevention of co-rotation and firm tightening.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. The drawing shows a structure for preventing co-rotation of screws, and a flanged bolt 11 and a nut 12 are provided in FIG.
These two members 11 and 12 are used to fasten and fix a plurality of members such as an iron plate, for example, two members 13 and 14 as mating members.

The above-mentioned flanged bolt 11 has a hexagonal column-shaped head 15, a flange portion 16, and a screw portion 17, and each of these elements 15, 16, 17 is made of a metal, such as boron steel, which is stronger than a general steel plate. (B steel), but the constituent material of the bolt 11 is not limited to this, and steel whose hardness is improved by heat treatment or other tough steel, that is, Ni-Cr steel, Ni-Cr- Mo steel, Cr-M
o steel, Mn steel, Mn-Cr steel or stainless steel or other metals. The head 15 does not necessarily have to be hexagonal.

The nut 12 described above has a disc spring washer 20 rotatably integrated with a nut body 18 via a caulking portion 19, so that both the nut body 18 and the disc spring washer 20 are made of metal. A plurality of co-rotation preventing protrusions 21 are integrally formed on the lower surface (flange bearing surface) of the flange portion 16 of the above-mentioned flanged bolt 11 as shown in FIGS.

As shown in FIG. 2, each of the co-rotation preventing projections 21 is integrally formed on the outer peripheral portion within the lower surface 16a (in the seating surface) of the flange portion 16. In the embodiment shown in FIG. Are formed at equal intervals.

Further, as shown in FIG. 3, each of the co-rotation preventing protrusions 21 has its base 21a (base) located on the lower surface 16a of the flange portion 16 and has an apex angle formed at an obtuse angle (see the angle θ). It has a substantially triangular shape.

Here, the above-mentioned substantially triangular shape is formed such that the bottom side 21a coincides with the radially inner and outer directions of the flange portion 16 as shown in FIG. Further, as shown in FIG. 3, a rounded portion 21b is formed at the substantially triangular vertex of each of the co-rotation preventing protrusions 21 described above.

Further, as shown in FIG. 4, each of the co-rotation preventing projections 21 has a wide bottom side (base side) when viewed from the radially outward or inward direction of the flange portion 16 and has a rounded portion as a vertex. 21b side (that is, the protruding end side) is configured in a tapered shape with a narrow width.

That is, the thickness of the round portion 21b is L1,
When the thickness of the bottom side 21a is L2, the relational expression of L2> L1 is established. In this embodiment, the above-mentioned taper is set at an angle α of about 30 degrees as shown in FIG. 4, but is not limited to this value.

The protrusion height H of the co-rotation preventing protrusion 21 is adjusted so that the protrusion 21 does not buckle or be damaged.
The thickness is set substantially equal to the thickness L1 of 1b. Further, the above-described co-rotation prevention projection 21 is provided with a recess for forming the projection 21 in advance on the mold side when the flanged bolt 11 is forged, and is integrally formed simultaneously with the forging, and the taper indicated by the angle α in FIG. Represents the draft angle of the forged product.

The bolt with flange 1 constructed as described above
For example, two members 1
To tighten and fix the bolts 3 and 14, as shown in FIG. 1, the threaded portion 17 of the flanged bolt 11 is inserted into the bolt insertion holes of the two members 13 and 14 from one side, and the bolt side is not rotated. When the nut 12 is screwed into the screw portion 17 from the other side of the two members 13 and 14 and tightened, a plurality of co-rotation prevention protrusions 2 are formed.
1 penetrates into the mating material 13 and its co-rotation and loosening are prevented.

As described above, the screw co-rotation prevention structure of the embodiment shown in FIGS. 1 to 4 is formed by integrally forming a plurality of co-rotation prevention protrusions 21 on the flange lower surface 16a of the flanged bolt 11. The prevention projection 21 has a substantially triangular shape in which the bottom side 21a is located on the flange lower surface 16a and the apex angle is formed at an obtuse angle (see the angle θ in FIG. 3).

According to this configuration, the flanged bolt 1
When tightening the mating member (refer to the two members 13 and 14) using the nut 1 and the nut 12, the bolt side 11 as the screw having the co-rotation prevention protrusion 21 is not rotated, and the nut 12 is fixed to the bolt 11 In this case, the co-rotation prevention projection 21 cuts into a mating material, and
Corotation and loosening can be prevented.

In addition, since the above-described co-rotation preventing projection 21 is formed in a substantially triangular shape having an obtuse obtuse angle (see the angle θ in FIG. 3), the co-rotation preventing projection 21 can secure the biting property with respect to the mating material. Can be prevented from being broken or damaged.

The substantially triangular apex of the co-rotation preventing projection 21 is formed in a round shape (see a round portion 21b). According to this configuration, the co-rotation prevention protrusion 21
Is formed in a rounded shape, so that the mating member to be tightened is not damaged except at a portion where the projection 21 bites.

Further, as shown in FIG. 4, the co-rotation preventing projection 21 is formed in a tapered shape in which the bottom 21a is wide (see the thickness L2) and the apex is narrow (see the thickness L1). . According to this configuration, the co-rotation prevention protrusion 21 can be more easily bite into the counterpart material by the above-described tapered structure, and the tightening torque when the nut 12 is screwed can be reduced.

In addition, as shown in FIG. 2, the co-rotation preventing projection 21 is formed integrally with the outer periphery of the flange lower surface 16a. According to this configuration, since the co-rotation prevention protrusion 21 is located at the outer peripheral portion, the torque for preventing co-rotation increases, and the co-rotation prevention effect can be improved.

The above-mentioned co-rotation preventing protrusions 21 are formed at equal intervals by three to six (four in this embodiment). According to this configuration, there is no inclination of the bolt 11 at the time of tightening, and no extra tightening force is required. In other words, if the number of co-rotation prevention protrusions is too small, the bolt tilts during tightening. Conversely, if the number of co-rotation prevention protrusions is too large, extra tightening force is required. Since the number of the prevention protrusions 21 is appropriately set, there is no inclination of the bolt 11 at the time of tightening, and no extra tightening force is required. In addition, since the plurality of co-rotation prevention protrusions 21 are formed at equal intervals, the plurality of co-rotation prevention protrusions 21 bite into the counterpart material evenly.

Further, a nut 12 having a disc spring washer 20 rotatably integrated with a nut body 18 is screwed into the screw portion 17 of the flanged bolt 11.

According to this configuration, when the mating member (see the two members 13 and 14) is tightened by the above-mentioned bolt 11 and nut 12, the bolt 1 is displaced by the spring force of the disc spring washer 20.
The first co-rotation prevention protrusion 21 is pulled toward the mating member, thereby achieving both more reliable prevention of co-rotation and firm tightening.

FIG. 5 shows another embodiment of the structure for preventing co-rotation of screws. In this embodiment, a total of three screws are provided at equal intervals of 120 degrees around the outer periphery of the flanged lower surface 16a of the flanged bolt 11. Are integrally formed.

Even with this configuration, the other configurations, operations, and effects are the same as those of the previous embodiment.
In the figure, the same parts as those in the previous figure are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 6 shows still another embodiment of the structure for preventing co-rotation of screws. In this embodiment, a flanged bolt 1 is shown.
A total of six co-rotation preventing protrusions 21 are integrally formed on the outer peripheral portion of the lower surface 16a of the first flange portion at equal intervals of 60 degrees.

Even with this configuration, the other configurations, operations, and effects are the same as in the previous embodiment.
In the figure, the same parts as those in the previous figure are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 7 shows still another embodiment of the structure for preventing the co-rotation of the screws.
In the above-described flanged bolt 11 in which the a and the screw portion 17 are integrated, the flange portion lower surface 16a side has a large diameter at the bolt neck portion, and the screw portion 17 side has the screw portion 1
7 is provided with a tapered portion 22 having a smaller diameter than the flange portion lower surface 16a side under the same conditions as the outer diameter.

As described above, the tapered portion 22 having the large diameter on the lower surface 16a side of the flange portion 16 is provided on the above-mentioned bolt neck portion.
Is provided, a bolt insertion hole formed in the mating member (see the two members 13 and 14) due to the formation of the tapered portion 22 described above.
(So-called bolt holes) and the bolt 11 can be aligned.

In this embodiment shown in FIG.
Other configurations, operations, and effects are almost the same as those of the previous embodiment. Therefore, in FIG. 7, the same portions as those in the previous drawings are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 8 shows still another embodiment of the structure for preventing the co-rotation of the screws.
Although the co-rotation prevention protrusions 21 are integrally formed on the bolt 11 side having the nut 6, the plurality of co-rotation prevention protrusions 21 are integrally formed on the lower surface 23a (seat surface) of the flange portion 23 on the nut 12 side in this embodiment shown in FIG. It is formed.

Here, the above-mentioned nut 12 is the nut body 1
8, a flanged portion 23 and a screw hole 24 made of a metal, desirably a tougher steel such as a boron steel which is stronger than a general steel plate, a steel whose hardness is improved by heat treatment, a chromium molybdenum steel, a stainless steel or the like. Composed of metal.

The detailed structure of the above-described co-rotation preventing projection 21 with respect to the lower surface 23a of the flange portion 23 is similar to that of the bolt 11
The configuration is the same as the configuration of the co-rotation prevention protrusion 21 provided on the side (see FIGS. 2 to 4).

As described above, the co-rotating structure of the screw of the embodiment shown in FIG. 8 is formed by integrally forming a plurality of co-rotation preventing projections 21 on the lower surface 23a of the flange portion of the flanged nut 12. Is the bottom side of the flange portion lower surface 23a
(Base) is located, and the apex angle is formed in an approximately triangular shape with an obtuse angle formed.

According to this configuration, the flanged nut 1
When tightening the mating member (see the two members 13 and 14) using the bolt 2 and the bolt 11, after the nut 12 is screwed to a certain extent with the screw portion 17, the co-rotation preventing protrusion 2 is formed.
The nuts 12 as the screws on the side having No. 1 are non-rotating, and the bolts 11 as the screws on the side not having the nut 1
In this case, the above-described co-rotation prevention projection 21 bites into the counterpart material (see the member 14), and thus co-rotation and loosening can be prevented.

However, since the above-described co-rotation prevention protrusion 21 is formed in a substantially triangular shape having an obtuse angle at the apex angle, it is possible to secure the biting property with respect to the counterpart material (see the member 14), to prevent breakage of the co-rotation prevention protrusion 21, Damage can be prevented.

In this embodiment shown in FIG.
Other configurations, operations, and effects are almost the same as those of the previous embodiment. Therefore, in FIG. 8, the same portions as those in the previous figure are denoted by the same reference numerals, and detailed description thereof will be omitted. In the example, the bolt 11 to be screwed to the nut 12 may not necessarily be a bolt with a flange, or a flat washer and / or a spring washer (not shown) may be provided between the head 15 of the bolt 11 and the mating member 13. Of course, it may be interposed.

In the correspondence between the configuration of the present invention and the above-described embodiment, the screws of the present invention are similar to the bolts 1 with flanges.
1 (see FIGS. 1 and 7) or the flanged nut 12 (see FIG. 8). Similarly, the lower surface of the flange is the lower surface 16a of the flange portion 16 on the bolt 11 side or the flange portion 23 on the nut 12 side. The configuration of the apex of the apex corresponding to the lower surface 23a corresponds to the radius 21b, but the present invention is not limited to only the configuration of the above-described embodiment.

[0050]

According to the present invention, a plurality of substantially triangular anti-corotation protrusions having a base located on the lower surface of a flanged bolt or a nut with a flange and having an apex angle formed at an obtuse angle. By integrally forming, it is possible to prevent co-rotation and loosening, of course, there is no breakage or breakage of the co-rotation prevention protrusion, and it is possible to obtain the effect that the co-rotation prevention protrusion satisfactorily bites into the mating material. it can.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a structure for preventing co-rotation of screws according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is an enlarged sectional view taken along the line BB of FIG. 2;

FIG. 4 is an enlarged sectional view taken along line CC of FIG. 2;

FIG. 5 is a sectional view showing another embodiment of the co-rotation prevention structure.

FIG. 6 is a sectional view showing still another embodiment of the co-rotation preventing structure.

FIG. 7 is an explanatory view showing still another embodiment of the structure for preventing co-rotation of screws according to the present invention.

FIG. 8 is a side view showing still another embodiment of the structure for preventing co-rotation of screws according to the present invention.

FIG. 9 is a sectional view showing a conventional co-rotation prevention structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Bolt 12 ... Nut 16 ... Flange part 16a ... Lower surface 17 ... Screw part 18 ... Nut body 20 ... Disc spring washer 21 ... Co-rotation prevention protrusion 21a ... Bottom 21b ... Round part 22 ... Tapered part 23 ... Flange part 23a ... Lower surface

Claims (7)

[Claims] A plurality of co-rotation preventing projections are integrally formed on a lower surface of a flange of a bolt with a flange or a nut with a flange. The co-rotation preventing projection has a base located on a lower surface of the flange and an apex angle formed at an obtuse angle. An anti-co-rotation structure for screws formed in a substantially triangular shape. 2. The screw and co-rotation prevention structure according to claim 1, wherein the substantially triangular apex of the co-rotation prevention projection is formed in a round shape. 3. The screw and co-rotation prevention structure according to claim 1, wherein the co-rotation prevention projection is formed in a tapered shape in which a bottom side is wide and a vertex side is narrow. 4. The co-rotation preventing projection is integrally formed on the outer periphery of the lower surface of the flange.
The described counter-rotating structure for screws. 5. The structure for preventing co-rotation of screws according to claim 1, 2, 3 or 4, wherein three to six co-rotation prevention protrusions are formed at equal intervals. 6. The screw according to claim 1, wherein the bolt neck portion in which the lower surface of the flange and the screw portion are integrated is provided with a tapered portion having a larger diameter on the lower surface side of the flange. A kind of co-rotation prevention structure. 7. The nut according to claim 1, 2, 3, 4, 5, or 6, wherein a nut having a disc spring washer integrally rotatably integrated with the nut body is screwed into the threaded portion of the flanged bolt. Co-rotation prevention structure for screws.