TW201305452A - Fastener and fastening structure - Google Patents

Abstract

The present invention provides a fastening structure with a high anti-loosing effect. The present invention is a fastening structure in that a thread 10 of fastening structure 1 comprising at least a portion that is constituted by an upper part 11 that is the top of the thread and a lower part 12 that is the bottom of the tread. Wherein the load bearing tooth flank 13 and the non-load bearing tooth flank 14 are formed in the upper part 11 and the load bearing side face 15 and the non-load bearing side face 16 are formed in the lower part 12. The load bearing side face 15 is formed by continuously extending from the lower end of the load bearing tooth flank 13 and in a cross-section containing the axis of the fastening structure 1, the load bearing side face 15 is formed by continuously extending from the lower end of load bearing tooth flank 13 in such a way that the contour of the load bearing side face 15 comprises a curved shape that is inwardly curved with respect to an extension line of the load bearing tooth flank 13 or a combined configuration of a linear shape that is arranged inside the extension line of the load bearing tooth flank 13 and a curved shape that is inwardly curved with respect o the extension line.

Description

Fastening member and fastening structure

The present invention relates to a fastening member and a fastening structure.

Conventionally, a fastening member having a screw structure such as a bolt or a nut has been widely used. In fact, in order for the bolt or nut to be locked, it is necessary to design dimensional tolerances for the outer diameter and effective diameter of the bolt, as well as the inner diameter and effective inner diameter of the nut. On the other hand, there is a possibility of slack due to the tolerance. In the past, various efforts have been made to prevent the occurrence of this slack.

In Patent Document 1, a fastening thread is disclosed which is in a flank on both sides of a thread of a male thread or a female thread, and is directed to a crimping side flank which is a crimping side in a fastening state, The front end side of the thread forms a flat abdomen and is extended by the flat abdomen to form a crimping side abdomen, and the inclination of the crimping side abdomen is more inclined than the inclination of the female thread or the male thread opposite thereto The big way to form.

Patent Document 2 discloses a male thread which is formed such that the outer diameter of the thread is larger than a standard value, and is formed such that the half angle of the head side of the thread is an angle smaller than 30 degrees.

Further, there is a method of preventing slack by forming a resin coating layer on a part of the thread.

Further, as another prior art document disclosed as a technique related to the present invention, please refer to Patent Document 3 to Patent Document 7.

[Previous Technical Literature] (Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. 2006-57801

Patent Document 2: Japanese Laid-Open Patent Publication No. 9-100825

Patent Document 3: Japanese Laid-Open Patent Publication No. 6-87713

Patent Document 4: Japanese Laid-Open Patent Publication No. 2005-61602

Patent Document 5: Japanese Patent Publication No. 48-13902

Patent Document 6: Japanese Unexamined Patent Publication No. 3-6115

Patent Document 7: Japanese Utility New Case Registration No. 3031085

In the technique of Patent Document 1, since the flat abdomen and the abutting side abdomen are planar, when a large fastening force is applied to the thread, stress is easily concentrated on the flat abdomen and the aforementioned pressure. The connecting portion of the side of the tooth is abutted, and the connecting portion is liable to cause plastic deformation or cracking.

Further, in the technique of Patent Document 1, the mating side fastening member is fastened to a fastening member provided with the flat abdomen and the pressure contact side abdomen. Here, the flank angle of the pressure-contact side flank (pressure side flank surface) of the mating-side fastening member is different from the flank angle of the flat tooth abdomen of the fastening member, so the crimping of the mating-side fastening member The contact area between the side abdomen and the flat abdomen is small, and a large frictional force cannot be obtained, so that there is a problem that a sufficient anti-loosening effect cannot be produced.

In the technique of Patent Document 2, it is described that if the tightening torque is gradually increased and the pressing force is increased, the thread of the male screw is elastically deformed and brought into contact with the bottom of the female thread to gradually enlarge the contact portion (refer to [ Paragraph of 0009].

However, in the technique of Patent Document 2, the flank angle of the pressure side flank surface of the male screw is different from the flank angle of the ventral surface of the pressure side of the female screw, so that the contact is made even as the pressing force becomes larger. As the part gradually becomes larger, a large frictional force cannot be obtained in the contact portion due to plastic deformation, and thus there is a problem that a sufficient anti-loosening effect cannot be produced.

Further, a method of preventing loosening by forming a resin coating layer on a part of the screw has a problem that it is necessary to form a resin coating layer again when the thread is used again, which is laborious.

Further, in the conventional configuration including Patent Documents 1 and 2, there is a so-called "initial relaxation" in which the elastic force of the seat surface is weakened. If the initial slack is left untreated, the axial force is reduced, the bolts are excessively stressed, and the bolts are broken. It is quite difficult to prevent such initial slack, and the countermeasure is only to increase the tightening force.

Also, when galvanizing is applied to the male thread or the female thread, in order to prevent the male thread from being inserted into the female thread due to the thickness of the plating, it is necessary to make the female thread larger than usual (that is, "over-tapping" tooth").

When such excessive tapping is applied to the conventional configuration including Patent Documents 1 and 2, the gap between the ventral surface of the male screw and the ventral surface of the female screw becomes large, and the ventral surface of the male thread and the female thread are enlarged. The friction between the ventral surfaces is greatly reduced, and friction is not obtained. Therefore, in the conventional configuration, it is extremely difficult to maintain the anti-loosening effect and perform plating with a large thickness such as galvanization.

The present invention has been made to solve the above problems, and has at least one of the following objectives.

(1) A fastening member or fastening structure having a high anti-loosening effect is provided.

(2) A fastening member or a fastening structure that can be locked in the same manner as a general bolt to easily manage torque and that can be easily reused is provided.

(3) A fastening member or a fastening structure for reducing the load load on the first screw of the fastening member, preventing stress concentration, and thereby improving fatigue strength is provided.

(4) A fastening member or a fastening structure that prevents initial slack from occurring is provided.

(5) A fastening member or a fastening structure is provided which can maintain the anti-loosening effect and can apply plating with a large thickness.

The inventors of the present invention have considered various viewpoints of the present invention as a result of many reviews in order to solve the above problems, as described below.

The first aspect of the present invention is defined as follows.

A fastening member is provided with a fastening member on a top portion of a thread on a top side of a thread and a lower portion on a bottom side of a thread on at least a part of a thread, wherein a pressure side flank surface is formed on the upper portion The gap side flank surface is formed with a side surface on the pressure side and a side surface on the gap side, and the side surface on the pressure side is formed by continuously extending from the lower end of the pressure side flank surface, and includes the fastening member In the cross section of the axis, the shape of the side surface on the pressure side is a curved shape which is curved inward on the extension line of the pressure side flank surface, or is based on an extension of the pressure side flank surface. The shape of the straight line disposed on the inner side and the curved shape curved toward the inner side based on the extension line are combined.

According to the fastening member defined by the first aspect, the side surface on the pressure side of the lower portion of the thread is of a specific shape (in the cross section including the axis of the fastening member, the inner side of the pressure side flank surface is bent and bent inward) a curved shape, or a shape in which a straight line shape disposed on the inner side of the flank surface of the pressure side is combined with a curved shape that is curved inward by the extension line) When the force from the mating side fastening member due to the locking is received, although the whole is deformed toward the gap side, the deformation is concentrated on the side of the pressure side to elastically deform the portion. In other words, the force from the mating side fastening members preferentially induces elastic deformation of the side of the pressure side. As a result, the entire thread is deformed toward the gap side (elastic deformation of the entire thread). On the other hand, if there is no such side on the pressure side, the load applied to the screw will concentrate on the top of the thin screw, causing the top of the screw to deform and possibly causing plastic deformation there.

Although the screw is integrally deformed, the deformation concentrates on the side of the pressure side of the specific shape to cause elastic deformation, so that the screw has to return to the original shape to generate a large reaction force. Thereby, there is a large reaction force between the pressure side flank surface of the fastening member and the pressure side flank surface of the mating side fastening member, thereby generating a frictional force and surely producing a loosening effect.

The side of the pressure side has a specific shape (in the cross section including the axis of the fastening member, the curved shape is curved toward the inner side based on the extension line of the pressure side flank surface, or the extension of the ventral surface of the pressure side The straight line shape disposed on the inner side and the curved shape that is curved on the inner side based on the extension line are combined. Therefore, even if stress is concentrated during deformation, plastic deformation or cracking hardly occurs. problem. This is because the stress acts in a direction in which the curved portion is expanded, and is widely and uniformly dispersed in the curved portion.

Although it is preferable to impart the above configuration to all of the continuously extending threads, it is possible to impart only the portion that is screwed to the mating side fastening members.

If the shape of the side surface is also provided on the gap side of the screw, although the lower portion of the screw is thin, the entire thread is easily elastically deformed, but compared with the case where the elastic deformation is concentrated on the side of the pressure side in the present case, many years later It is also easier to lose the elastic force and cause plastic deformation of the entire thread.

The previous fastening member exerts a maximum load on the first thread when it is screwed with the mating side fastening member.

On the other hand, according to the fastening member defined in the first aspect, the force applied to the first thread is dispersed to the second thread by the elastic deformation of the first thread itself, and the second thread is also elastic. The deformation, so that the force applied to the second screw can be dispersed to the third screw. Thus, the plurality of threads can be used to withstand the force from the mating side fastening members continuously to the third screw, the fourth screw, and the like.

Thereby, the load applied to the first screw is dispersed to prevent stress from being concentrated to the bottom of the first screw. Thus, the fatigue strength can be improved and the breakage of the thread can be prevented. Moreover, it is ensured that the fastening member can be reused.

In the case where excessive tapping is provided, since the pitch is the same, the pressure side flank surface of the fastening member and the pressure side flank surface of the mating side fastening member are sure to come into contact. Therefore, the thread generates a sufficient reaction force between the pressure side flank surface and the pressure side flank surface of the mating side fastening member, thereby exerting a loosening effect.

The second point of view is as follows. In the above-described pressure side flank surface, the lower end of the pressure side flank surface is the farthest from the pressure side flank surface of the reference tooth shape and protrudes toward the pressure side. Here, the pressure side direction is a direction in which a plurality of threads constituting the fastening member are provided on the pressure side flank side.

According to the fastening member of the second aspect as defined above, when the fastening member is screwed into the mating side fastening member, the lower end of the pressure side flank surface is first brought into contact with the pressure side flank surface of the mating side fastening member. Thereby, the force from the mating side fastening member is first applied to the lower end of the thread (that is, the connection portion between the pressure side flank surface and the side surface). Thereby, the force can efficiently induce elastic deformation of the side of the specific shape.

Further, since the mating-side fastening member is slowly abutted against the upper side (the screw top side) by the lower side (bottom side) of the screw, plastic deformation of the screw top side can be more reliably prevented.

The third aspect of the invention is defined as follows. In the fastening member according to the second aspect, the pressure side flank surface is integrally provided closer to the pressure side direction than the pressure side flank surface of the reference tooth shape.

According to the fastening member defined in the third aspect, the aforementioned actions and effects of the second aspect can be obtained more surely.

The fourth aspect of the invention is defined as follows. In the fastening member according to any one of the first aspect to the third aspect, the gap side flank surface coincides with the gap side flank surface of the reference tooth shape.

According to the fastening member defined in the fourth aspect, the aforementioned actions and effects of the first to third aspects can be obtained more surely.

The fifth aspect of the invention is defined as follows. The fastening member according to the second aspect or the third aspect, wherein the thread is inclined toward the pressure side direction with a pair of bottom portions of the reference tooth shape as a base point, and the thread top and the pressure side are The ventral surface of the flank and the ventral surface of the flank are located closer to the pressure side than the corresponding portion of the reference profile.

In the fastening member of the fifth aspect thus defined, since the entire screw is inclined toward the pressure side, when the fastening member is screwed into the mating side fastening member, the force received by the mating side fastening member is expressed. A greater resistance. As a result, a greater elastic force can be generated.

The sixth aspect of the invention is defined as follows. The fastening member according to any one of the second aspect to the fifth aspect, wherein the flank angle of the pressure side flank surface is formed more than the flank angle of the pressure side flank surface of the reference tooth shape Large, the angle difference between the two flank angles is below 3°.

If the ventral angle of the ventral surface of the pressure side is more than 3°, it is feared that the lower end of the ventral surface of the pressure side (that is, the connection between the pressure side flank surface and the pressure side side) will be plastically deformed, where the absorption from the mating side is tight. The strength of the solid member does not efficiently induce elastic deformation of the side of the pressure side.

The lower limit of the angular difference between the two flank angles is not particularly limited, but exceeds the general tolerance.

The seventh aspect of the present invention is defined as follows. The fastening member according to any one of the first aspect to the sixth aspect, wherein the lower end of the pressure side flank surface is located at a height of a reference tooth shape 1/3 or more to 2/3 or less.

If the lower end of the pressure side flank of the fastening member exceeds 2/3 of the height of the reference tooth, the ratio in the lower middle portion of the screw is too large. The lower pressure side side is hollowed out (digging), so it may not be possible to ensure sufficient strength of the fastening member.

Further, if the lower end of the pressure side flank surface of the fastening member is less than 1/3 of the height of the reference tooth, the sufficient curved portion cannot be secured on the side surface of the lower portion of the thread, and the elastic deformation of the portion is insufficient. So not good.

The lower end of the pressure side flank surface of the fastening member is preferably located at the pressure side flank surface of the mating side fastening member in the fastening state (the pressure side flank surface of the mating side fastening member is covered tightly) The side of the pressure side of the solid member).

Thereby, the pressure side flank surface and the extending portion (continuous portion) of the side surface extending therefrom are surely contacted to the pressure side flank surface of the mating side fastening member, based on the force from the mating side fastening member The elastic deformation of the side of the pressure side is surely caused.

The eighth aspect of the invention is defined as follows. The fastening member according to any one of the first aspect to the seventh aspect, wherein the pressure side side surface has a pressure side flank surface The linear shape of the inner side is a combination of a straight line shape disposed on the inner side and a curved shape curved toward the inner side based on the extension line, and the linear shape is a straight line perpendicular to the axis of the fastening member.

According to the eighth aspect, the aforementioned effects and effects of the first aspect can be obtained more surely.

The ninth aspect of the invention is defined as follows. The fastening member according to any one of the first aspect to the eighth aspect, wherein the side surface on the gap side is formed on the same plane as the flank surface of the gap side.

In the fastening member described in the ninth aspect, the gap-side flank surface is extended to the continuous shape of the thread bottom portion in maintaining the planar shape. Therefore, when the fastening member is screwed into the mating-side fastening member, The force received by the mating side fastening members exhibits greater resistance. Therefore, a larger reaction force can be generated.

The tenth aspect of the present invention is defined as follows. That is, a fastening structure is a fastening member having the fastening member as described in any of the first to ninth aspects, and a fastening structure of the mating-side fastening member to be fastened to the fastening member Where: when the aforementioned fastening member is fastened to the mating side fastening member, the pressure side flank surface of the fastening member is in contact with the mating side fastening member, and the side of the pressure side of the fastening member is paired with the aforementioned The side fastening members are isolated. According to the tenth point of view, the aforementioned actions and effects of the first to ninth aspects can be obtained more surely.

The eleventh aspect of the present invention is defined as follows. That is, a fastening method is a fastening method of fastening a fastening member as described in the second aspect or the third aspect to a mating side fastening member to be fastened to the fastening member When the fastening member is screwed into the mating side fastening member, the lower end of the pressure side flank surface of the fastening member is first brought into contact with the pressure side flank surface of the mating side fastening member.

According to the eleventh aspect, the aforementioned effects and effects of the second or third viewpoint can be obtained more surely.

Hereinafter, each embodiment in which the present invention is embodied will be described in detail with reference to the drawings. In the respective embodiments, the same components and components are denoted by the same reference numerals, and the description of the same components will be omitted.

<First Embodiment>

Fig. 1 is a front view of the bolt 1 in a non-fastened state, and the bolt 1 has the threads 10, 20, 30, 40, 100, 200, and 300 of the respective embodiments.

The fastening member, that is, the bolt 1, has a male screw structure, and includes a head portion 2, a cylindrical portion 3, a threaded portion 4, and an axis 5. A seating surface 6 is formed on the surface of the head portion 2 on the side of the cylindrical portion 3. A thread 10 is formed on the threaded portion 4.

Fig. 2(A) is an enlarged cross-sectional view showing the thread 10 of the thread 10 shown in Fig. 1.

The virtual cylinder 7 is an imaginary cylinder that defines the effective diameter of the reference tooth 8.

In other words, the effective diameter is the diameter of the virtual cylinder 7 when the width of the spiral groove measured in the direction of the axis 5 of the reference tooth 8 is equal to the width of the thread.

The reference tooth shape 8 includes a male screw bottom portion 81a and 81b, a pressure side tooth surface 82, and a gap side tooth surface 83.

The axis of the reference tooth 8 is the same as the axis 5 of the thread 10.

The reference tooth shape 8 is a theoretical thread shape defined by the JIS standard. For example, in this example, the thread angle θ1 of the reference tooth shape 8 is about 60°, and the flank angle θ2 of the pressure side flank surface 82 and the gap side are The flank angle θ3 of the ventral surface 83 is about 30°.

Each of the imaginary lines 84a, 84b passes through the male screw bottoms 81a, 81b of the reference tooth 8, respectively, and is orthogonal to the axis 5.

The pitch (pitch) of the reference teeth 8 is the distance between the bottoms 81a, 81b of the male screw measured parallel to the axis 5.

The thread 10 of the first embodiment includes an upper portion 11 closer to the male screw top portion 10a than the virtual cylinder 7, and a lower portion 12 closer to the male screw bottom portions 10b and 10c than the virtual cylinder 7.

On the upper portion 11 of the thread 10, a pressure side flank surface 13 and a gap side flank surface 14 are formed.

The flank angle θ2 of the pressure side flank 13 of the thread 10 is approximately the same as the flank angle of the pressure side flank 82 of the reference tooth 8, and is about 30°.

The flank angle θ3 of the gap side flank surface 14 of the thread 10 is approximately the same as the flank angle of the gap side flank surface 83 of the reference tooth form 8, and is about 30 degrees.

Therefore, the angle θ1 of the thread 10 is approximately the same as the reference tooth shape 8, and is about 60°.

Furthermore, the pitch of the thread 10 is the same as that of the reference tooth 8.

On the lower portion 12 of the thread 10, the side surface 15 on the pressure side (the seat surface 6 side (see FIG. 1)) and the side surface 16 on the gap side (thread front end side) are formed.

The shape of the side surface 15 on the pressure side is continuous with the extension line of the pressure side flank surface 13 (the line along the pressure side flank surface 82 of the reference tooth shape 8) on the cross section including the axis 5, and is continuously curved while being curved inside. Extending to the R shape of the bottom 10b of the male screw. In other words, it is a shape that is hollowed out (digging) from the extension surface of the ventral surface of the pressure side.

Further, the side surface 15 on the pressure side continuously extends from the male screw bottom portion 10b to the side surface on the gap side, and the side surface on the gap side is a screw thread (not shown) adjacent to the pressure side (the seat surface 6 side). in.

The shape of the side surface 16 on the gap side is on the same plane as the gap side flank surface 14 on the cross section including the axis 5, and the gap side flank surface 14 is extended to the continuous shape of the male screw bottom portion 10c so as to maintain the planar shape.

Further, the side surface 16 on the gap side is continuously extended from the male screw bottom portion 10c to the pressure side side surface, and the pressure side side surface is in the thread adjacent to the gap side (thread front end side).

In the thread 10, the lower end 13a of the pressure side flank 13 (the upper end of the side surface 15 on the pressure side) is formed in the vicinity of the virtual cylinder 7 (the position near the effective diameter of the reference tooth 8).

Fig. 2(B) is a cross-sectional view showing the thread 10 in a state in which the nut 9 of the mating side fastening member is fastened to the bolt 1 of the first embodiment.

The nut 9 has a female screw structure and includes a pressure side flank surface 91, a gap side flank surface 92, a female thread top 9a, and a female thread bottom 9b.

The nut 9 has a shape conforming to the JIS standard, and the angle θ4 of the female nut bottom portion 9b is about 60°, and the flank angle of the pressure side flank surface 91 and the flank angle of the gap side flank surface 92 are both about 30°. .

Further, the method of manufacturing the bolt 1 is not particularly limited, and any manufacturing method may be employed. For example, various types of rolling, cutting, and casting may be employed (flat mode, circular mode, planetary plastic mode, rotary plastic mode, etc.). Known methods such as forging, injection molding, and the like.

Further, the side surface (hollowed portion) of the lower portion 12 is preferably formed in all areas of the screw portion 4 of the bolt 1, but it may be formed only in a portion that is screwed to the nut.

Moreover, the shape of the side surface of the lower portion of each thread can also be different. For example, the amount of hollowed out on the pressure side of the lower portion of the screw becomes larger as it goes away from the seat surface. More specifically, the radius of curvature of the side surface 15 is defined to gradually increase as it moves away from the seating surface.

According to the same opinion, the position of the lower end of the ventral surface of the pressure side of each screw can be arbitrarily changed. For example, the lower end position of the first screw is set to the bottommost side, and the lower end position is displaced toward the top side as the front end of the bolt moves.

As shown in Fig. 2(B), when the thread 10 of the bolt 1 is screwed into the nut 9, the pressure side flank 91 of the nut 9 presses the pressure side flank surface 13 of the thread 10.

Here, the side surface 15 on the pressure side of the lower portion 12 of the thread 10 is bent toward the inside as a function of the extension surface of the pressure side flank surface 82, and continuously extends to the cross-sectional curve shape of the thread bottom portion 10b, so When the force from the nut 9 causes the screw to deform toward the front end side of the bolt (the right side of the drawing), the deformation is mostly concentrated on the side surface 15 on the pressure side to be elastically deformed. By this elastic deformation, a large reaction force is obtained, so that a large frictional force is generated between the two flank surfaces 13, 91.

Fig. 3 and Fig. 4 show a modification of the first embodiment. The same elements in the third and fourth aspects are denoted by the same reference numerals, and their description will be omitted.

In the first variation (screw 20) shown in Fig. 3, the lower end 13a of the pressure side flank 13 (the upper end of the side surface 15 on the pressure side) is formed closer to the top of the male screw than the imaginary cylinder 7. The position on the side of 10a (the position outside the effective diameter of the reference tooth 8).

Further, in the second modification (thread 30) shown in Fig. 4, the lower end 13a of the pressure side flank 13 (the upper end of the side surface 15 on the pressure side) is formed closer to the male snail than the imaginary cylinder 7. The position on the side of the tooth bottom 10b, 10c (the position within the effective diameter of the reference tooth shape 8).

The fastening members of these variations have the same effects as the fastening members of Fig. 2.

Fig. 5 is an enlarged cross-sectional view showing the side surface 15 on the pressure side of the screw 40 of the third modification. In the fifth embodiment, the same elements as those in the second embodiment are denoted by the same reference numerals, and their description will be omitted.

In the thread 40 of the third modification, the shape of the side surface 15 on the pressure side is an extension line of the pressure side flank surface 13 in the cross section including the axis 5 (the pressure side flank surface along the reference tooth shape 8) A line 41 disposed on the inner side of the line 82 is combined with a curved line 42 curved inward on the extension line.

The straight line 41 is perpendicular to the axial direction of the bolt 1 (see FIG. 2) (parallel to the imaginary line 84a), and the upper end of the straight line 41 is connected to the lower end 13a of the pressure side flank surface 13.

Curve 42, the upper end 42a is connected to the lower end of the straight line 41, and the lower end thereof is an R shape that extends to the bottom 10b of the male screw.

According to the thread 40 of such a configuration, in addition to the same anti-loosening effect as the screw of the example of Fig. 2, the anti-loosening effect can be improved.

Here, the upper end of the straight line 41 (the lower end 13a of the pressure side flank surface 13) is the same as the first modification (see Fig. 3), and is preferably closer to the side of the male screw top 10a than the imaginary cylinder 7. (The position outside the effective diameter of the reference tooth 8).

Further, the upper end of the straight line 41 moves toward the position on the side of the male screw top 10a as compared with the virtual cylinder 7, and the screw 40 is more easily deformed.

Further, the straight line 41 can be inclined in the pressure side direction or the gap side direction without being parallel to the axial direction of the bolt 1 (see FIG. 2).

Here, the pressure side direction is a direction in which each of the screws 40 constituting the bolt 1 is provided on the pressure side flank surface 13 side.

In addition, the direction of the gap side is the direction in which each of the screws 40 constituting the bolt 1 is provided with the gap side flank surface 14 (not shown in FIG. 5, see FIG. 2).

Further, in the thread 10 of the second embodiment, in the cross section including the axis 5, the shape of the side surface 15 on the pressure side is set to a curved shape which is curved inward by the extension line of the pressure side flank surface 13 In the case, the shape of the curve is not limited to the R shape having a fixed radius of curvature, and may be a composite R shape in which a plurality of curved surfaces having different curvature radii are combined.

Further, in the thread 40 of Fig. 5, the curve 42 is not limited to the R shape, and may be a composite R shape.

<Second embodiment>

Fig. 6(A) is an enlarged cross-sectional view showing the thread 100 of the second embodiment of the thread 100.

Fig. 6(B) is a cross-sectional view showing the thread 100 in a state in which the nut 9 is fastened to the bolt 1 of the second embodiment.

The same elements as those in FIG. 2 in FIG. 6 are given the same reference numerals and their description will be omitted.

In the thread 100 shown in Fig. 6, the angle θ5 of the thread 100 is larger than the angle θ1 of the thread of the reference tooth 8. On the other hand, the flank angle θ3 of the gap side flank surface 14 is approximately the same as the flank angle of the gap side flank surface 83 of the reference tooth form 8, and is about 30 degrees.

The pressure side flank surface 101 of the thread 100 is formed along an imaginary line 86 which is on the flank angle θ2 (about 30°) of the pressure side flank surface 82 of the reference tooth shape 8 plus The angle θ6 (=3° or less) is formed, and the flank angle θ7 (= θ 2 + θ 6 ) of the pressure side flank surface 101 is about 30° to 33°.

Furthermore, the angle θ5 (= θ1 + θ6) of the thread 100 is approximately 60° to 63°.

According to the thread 100 of the second embodiment of the above-described configuration, in the pressure side flank surface 101, the lower end 101a of the pressure side flank surface 101 protrudes farther from the pressure side flank surface 82 of the reference tooth 8 toward the pressure side.

Further, the pressure side flank surface 101 of the thread 100 is entirely provided closer to the pressure side direction than the pressure side flank surface 82 of the reference tooth 8.

Here, the pressure side direction is a direction in which each of the screws 100 constituting the bolt 1 is provided on the pressure side flank surface 101 side.

According to the thread 100 of the sixth embodiment having such a configuration, when the bolt 1 is screwed into the nut 9, the lower end 101a of the pressure side flank surface 101 of the thread 100 is firstly abutted against the pressure side of the nut 9. Ventral surface 91.

As a result, the force from the nut 9 causes the elastic deformation of the side surface 15 through the lower end 101a. Moreover, this can be prevented from being concentrated toward the top side of the upper portion 11 with respect to the reaction force from the nut 9.

In order to surely obtain such an effect and effect, it is preferable to set the angle θ6 to a range of 3 or less.

If the angle θ6 exceeds 3°, when the lower end of the pressure side flank face first contacts the nut 9, the force from the nut 9 may cause plastic deformation of the lower end. If the lower end is plastically deformed, it will be offset from the elastic deformation caused by the force from the nut 9, which is not preferable.

<Third embodiment>

Fig. 7(A) is an enlarged cross-sectional view showing the threaded shaft 200 of the third embodiment including the axis 5.

Fig. 7(B) is a cross-sectional view showing the thread 200 in a state in which the nut 9 is fastened to the bolt 1 of the third embodiment.

The same elements as those in FIG. 2 in FIG. 7 are given the same reference numerals and their description will be omitted. The shape of the side surface 201 on the gap side of the thread 200 of Fig. 7 is an extension line of the gap side flank surface 14 in the cross section including the axis line 5 (the line along the gap side flank surface 83 of the reference tooth shape 8) The R shape continuously extending to the inner screw bottom portion 10c while being bent inwardly, and the side surface 201 on the gap side continuously extends from the male screw bottom portion 10c to the pressure side side surface, the pressure side side surface, It is in the thread adjacent to the gap side (thread front end side).

As shown in Fig. 7, the threaded teeth 200 are thinner than the lower portion 12 of Fig. 2. As a result, the former (the screw of Fig. 7) is more elastically deformed than the latter (the screw of Fig. 2). That is, it is preferable to review the bolt use or the bolt material, and appropriately adopt the configuration as shown in Fig. 7 in accordance with the required tightening torque.

Further, the position of the lower end 14a (the upper end of the side surface 201 of the gap side) of the gap side flank surface 14 of the thread 200 is preferably provided at the lower end 13a (the upper end of the side surface 15 on the pressure side) of the pressure side flank surface 13 Close to the lower side (bottom side).

When the R shape on the side surface of the gap side is increased (the position of the lower end 14a of the gap side flank surface 14 is increased), the R shape on the side surface of the pressure side is combined with each other to make the lower portion of the screw thin, which may cause plasticity of the entire thread. Deformation.

<Fourth embodiment>

Fig. 8 is an enlarged cross-sectional view showing the thread 400 of the screw 400 according to the fourth embodiment.

Fig. 9 is a cross-sectional view showing the thread 400 in a state in which the nut 9 is fastened to the bolt 1 of the fourth embodiment.

The same elements as those in FIG. 2 in FIGS. 8 and 9 are denoted by the same reference numerals and their description will be omitted.

In Fig. 8, the imaginary line 401 passes through the male screw bottom 81a of the reference tooth shape 8, and the imaginary line 84a which passes through the male screw bottom 81a and is orthogonal to the axis 5 is about the angle θ8 which is sandwiched by the imaginary line 401. It is 26°.

The imaginary line 402 passes through the male screw bottom 81b of the reference tooth shape 8, and the imaginary line 84b which passes through the male screw bottom 81b and is orthogonal to the axis 5, and the angle θ9 between the imaginary line 402 and the imaginary line 402 is about 33°.

The pressure side flank surface 403 of the thread 400 is formed along an imaginary line 404 which is formed by adding an angle θ10 (=3.5° to 6°) at an angle θ8 of the imaginary line 401, and the pressure side The ventral angle θ11 (= θ8 + θ10) of the ventral surface 403 is about 30.5° to 33°.

The gap side flank surface 405 of the thread 400 is formed along the imaginary line 402, and the flank angle θ9 of the gap side flank surface 405 is the same as the angle θ9 of the imaginary line 402.

Therefore, the thread angle θ12 (= θ9 + θ11) of the upper portion 11 of the screw 400 is approximately 63.5° to 66°.

The shape of the side surface 406 on the pressure side of the screw 400 is a straight line 407 and an imaginary line which are disposed on the inner side in the cross section including the extension line of the pressure side flank surface 403, that is, the imaginary line 404. The shape of the curve 408 which is bent toward the inside is combined with 404.

In other words, the shape of the side surface 406 on the pressure side is the same as the side surface 15 (see FIG. 5) on the pressure side of the screw 40 of the third modification of the first embodiment.

The shape of the side surface 16 on the gap side of the screw 400 is the same plane on the gap side flank surface 405 in the cross section including the axis 5, and the gap side flank surface 405 is extended to maintain the planar shape and continuously extends to the male snail. The shape of the bottom 10c of the tooth.

According to the screw 400 of the fourth embodiment of the above configuration, the lower end 403a of the pressure side flank surface 403 is protruded farther from the pressure side flank surface 82 of the reference tooth 8 in the pressure side flank surface 403, and is directed toward the pressure side. Therefore, the same effects as those of the second embodiment shown in Fig. 6 can be obtained.

That is, when the bolt 1 is screwed into the nut 9, the lower end 403a of the pressure side flank surface 403 of the screw 400 is firstly abutted against the pressure side flank 91 of the nut 9.

As a result, the force from the nut 9 is efficiently transmitted through the lower end 403a, and the side surface 406 is elastically deformed in the expanding direction. The elastic deformation of the side 406 on the pressure side generates a large reaction force, and a large frictional force is generated between the pressure side flank faces 403, 91. Further, by preferentially abutting the lower end portion 403a against the pressure side flank surface 91 of the nut 9, it is possible to prevent the force from the nut 9 from being concentrated toward the thin top side of the upper portion 11.

Since the screw 400 of this example is inclined toward the pressure side, the resistance to the force from the nut 9 is strong, and the example of Fig. 7 is used as a comparison object, and the whole is not easily elastically deformed. As a result, the force from the nut 9 is easily converted into elastic deformation of the side surface 406 on the pressure side.

Further, in the example of Fig. 8, the angle θ13 (= θ10 - θ9) obtained by subtracting the angle θ9 from the angle θ10 is preferably set to a range of 3 or less.

Here, the angle θ13 is also an angle (θ13=θ11−θ2) obtained by subtracting the flank angle θ2 of the pressure side flank surface 82 of the reference tooth 8 from the flank angle θ11 of the pressure side flank surface 403.

In other words, the angle θ13 of the fourth embodiment corresponds to the angle θ6 of the second embodiment and the range of the angle θ13, and the description of the range of the angle θ6 in the second embodiment can be directly applied.

In order to determine the locking effect of the bolt of this embodiment, a vibration test was performed.

The vibration test is a standard vibration test of the Kansai Test Center of the Japanese Quality Assurance Agency of Japan.

The sample was mounted to a high speed screw relaxation tester and tested under specific vibration conditions (vibration number: 1780 hz; vibration table stroke: 11 mm; impact stroke: 19 mm; vibration direction: at right angles to the bolt axis). Further, when the sample was attached to the high-speed screw relaxation tester, a vibration barrel and a gasket were sandwiched between the bolt and the nut, and the vibration sleeve was vibrated by the vibration table.

The sample is a M12 x 60 hex bolt and the hex nut is locked to the hex bolt with a torque of 80 N‧ m.

Examples 1-1 and 1-2 are those having the structure of Fig. 8, and Comparative Examples 1-1 and 1-2 are JIS specifications having a screw-shaped equivalent reference tooth shape. These are all made by plating trivalent chrome. The results are shown in Table 1.

The slack is judged to be slack when the alignment marks between the bolts, nuts, and washers of the sample are staggered, and the washer can be rotated by hand.

Further, in Example 1-3, the bolt of the sample of Example 1-2 was again loosened from the nut, and the result of the vibration test was again performed by screwing the nut under the same conditions.

<Other Embodiments>

[A] The above embodiments can be combined and implemented as appropriate. In this case, both the action and the effect of the combined embodiment can be achieved, and the multiplication effect can be obtained.

[B] In the above embodiments, the reference tooth shape 8 defined by the JIS standard and the nut 9 according to the JIS standard are applied. However, any standard that conforms to a known specification (for example, a uniform thread or a whitworth) can be applied.

[C] In the above embodiments, the right-hand threaded bolt is applied. However, the left-threaded bolt can be applied. When the left-threaded bolt is applied, the same action and effect as in the case of applying the right-threaded bolt can be obtained.

[D] In the above embodiments, the fastening member having the male screw structure is applied. However, the present invention is also applicable to the fastening member having the female screw structure, and the case where the male screw structure is applied can also be obtained. The same effect and effect.

[E] In the above embodiments, the bolt 1 having the head portion 2 is applied, and the seat surface 6 is formed in the head portion 2. However, the present invention is also applicable to a screw (for example, a set screw) that does not have a head portion.

The present invention is not limited to the foregoing various aspects and the description of the foregoing embodiments. Various modifications within the scope of the patent application are intended to be included in the invention. The contents of the papers, published patent publications, patent publications and the like disclosed in the present specification are hereby incorporated by reference.

1. . . Bolt (fastening member)

2. . . head

3. . . Cylinder

4. . . Thread part

5. . . Axis

6. . . Seat

7. . . Imaginary cylinder

8. . . Reference tooth shape

9. . . Nut

9a. . . Female nut top of nut 9

9b. . . The bottom of the nut of the nut 9

10. . . Screw

10a. . . Male screw top

10b. . . Male screw bottom

10c. . . Male screw bottom

11. . . Upper

12. . . Lower part

13. . . Pressure side ventral surface

13a. . . Lower end of the pressure side flank 13

14. . . Gap side of the gap

14a. . . The lower end of the ventral surface 14 of the gap side

15. . . Side of the pressure side

16. . . Side of the gap side

20. . . Screw

30. . . Screw

40. . . Screw

41. . . straight line

42a. . . Upper end

42. . . curve

81a. . . Male screw bottom

81b. . . Male screw bottom

82. . . The pressure side of the reference tooth 8

83. . . Gap side of the reference tooth 8

84a. . . Imaginary line

84b. . . Imaginary line

86. . . Imaginary line

91. . . The pressure side of the nut 9

92. . . Gap side of the nut 9

100. . . Screw

100a. . . Male screw top

101. . . Pressure side ventral surface

101a. . . Lower end of the pressure side flank 101

200. . . Screw

201. . . Side of the gap side

301. . . Side of the gap side

400. . . Screw

400a. . . Male screw top

401. . . Imaginary line

402. . . Imaginary line

403. . . Pressure side ventral surface

403a. . . Lower end of the pressure side flank 403a

404. . . Imaginary line

406. . . Side of the pressure side

407. . . straight line

408. . . curve

Fig. 1 is a front view of the bolt 1 in a non-fastened state, and the bolt 1 has a thread 10 according to the first embodiment of the present invention.

Fig. 2(A) is an enlarged cross-sectional view of the thread 10 shown in Fig. 1 including the axis 5, and Fig. 2(B) is a view showing the mating side fastening of the bolt 1 of the first embodiment. A cross-sectional view of the thread 10 in the state in which the member is the nut 9.

Fig. 3 is an enlarged cross-sectional view showing the thread 20 of the first modification of the first embodiment including the axis 5.

Fig. 4 is an enlarged cross-sectional view showing the thread 30 of the second embodiment of the first embodiment, including the axis 5.

Fig. 5 is an enlarged cross-sectional view showing a side surface 15 on the pressure side of the thread 40 of the third modification of the first embodiment.

Fig. 6(A) is an enlarged cross-sectional view showing the thread 100 of the screw 100 according to the second embodiment of the present invention, and Fig. 6(B) is a view showing the nut 9 fastened to the bolt 1 of the second embodiment. A cross-sectional view of the thread 100 in the state of the state.

Fig. 7(A) is an enlarged cross-sectional view showing the threaded shaft 200 of the third embodiment of the present invention including the axis 5, and Fig. 7(B) is a view showing the screw 9 fastened to the bolt 1 of the third embodiment. A cross-sectional view of the thread 200 in the state of the state.

Fig. 8 is an enlarged cross-sectional view showing the thread 400 of the screw 400 according to the fourth embodiment of the present invention.

Fig. 9 is a cross-sectional view showing the thread 400 in a state in which the nut 9 is fastened to the bolt 1 of the fourth embodiment.

1. . . bolt

5. . . Axis

7. . . Imaginary cylinder

8. . . Reference tooth shape

9. . . Nut

9a. . . Female thread top

9b. . . Female screw bottom

10. . . Screw

10a. . . Male screw top

10b. . . Male screw bottom

10c. . . Male screw bottom

11. . . Upper

12. . . Lower part

13. . . Pressure side ventral surface

13a. . . Lower end of the pressure side flank 13

14. . . Gap side of the gap

15. . . Side of the pressure side

16. . . Side of the gap side

81a. . . Male screw bottom

81b. . . Male screw bottom

82. . . The pressure side of the reference tooth 8

83. . . Gap side of the reference tooth 8

84a. . . Imaginary line

84b. . . Imaginary line

91. . . Pressure side ventral surface

92. . . Gap side of the gap

Claims (11)

A fastening member is provided with a fastening member on a top portion of a thread on a top side of a thread and a lower portion on a bottom side of a thread on at least a part of a thread, wherein a pressure side flank surface is formed on the upper portion The gap side flank surface is formed with a side surface on the pressure side and a side surface on the gap side, and the side surface on the pressure side is formed by continuously extending from the lower end of the pressure side flank surface, and includes the fastening member In the cross section of the axis, the shape of the side surface on the pressure side is a curved shape which is curved inward on the extension line of the pressure side flank surface, or is based on an extension of the pressure side flank surface. The shape of the straight line disposed on the inner side and the curved shape curved toward the inner side based on the extension line are combined. The fastening member according to claim 1, wherein in the pressure side flank surface, the lower end of the pressure side flank surface is farthest from the pressure side flank surface of the reference tooth shape and protrudes toward the pressure side. The fastening member according to claim 2, wherein the pressure side flank surface is integrally provided closer to the pressure side direction than the pressure side flank surface of the reference tooth shape. The fastening member according to any one of the preceding claims, wherein the gap side flank surface coincides with the gap side flank surface of the reference tooth shape. The fastening member according to claim 2, wherein the thread is inclined toward the pressure side by a pair of bottom portions of the reference tooth shape, and the screw top and the pressure side are The ventral surface of the flank and the ventral surface of the flank are located closer to the pressure side than the corresponding portion of the reference profile. The fastening member according to claim 2, wherein the flank angle of the pressure side flank surface is formed to be larger than the flank angle of the pressure side flank surface of the reference tooth shape, two The angle difference between the flank angles is below 3°. The fastening member according to any one of claims 1 to 3, wherein the lower end of the pressure side flank surface is located at 1/3 or more to 2/3 or less of the height of the reference tooth. s position. The fastening member according to any one of the preceding claims, wherein the shape of the side surface on the pressure side is disposed on the inner side of the extension of the pressure side flank surface. The linear shape is a combination of a curved shape curved inwardly from the extension line, and the linear shape is a straight line perpendicular to the axis of the fastening member. The fastening member according to any one of the preceding claims, wherein the side surface on the gap side is formed on the same plane as the flank surface of the gap side. A fastening structure comprising a fastening member according to any one of claims 1 to 9 and a fastening structure of a mating side fastening member to be fastened to the fastening member Where: when the aforementioned fastening member is fastened to the mating side fastening member, the pressure side flank surface of the fastening member is in contact with the mating side fastening member, and the side of the pressure side of the fastening member is paired with the aforementioned The side fastening members are isolated. A fastening method for fastening a fastening member according to item 2 or 3 of the patent application with a mating side fastening member to be fastened to the fastening member When the fastening member is screwed into the mating side fastening member, the lower end of the pressure side flank surface of the fastening member is first brought into contact with the pressure side flank surface of the mating side fastening member.