JP2001271820A - Locking nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a locking nut excellent in productivity in a simple structure, superior in workability for fastening, capable of preventing threadably attaching force from being reduced, when external force such as vibration and the like is applied on a material to be fastened and a bolt, capable of maintaining high fastening force for a long time, and capable of enhancing safety of the fastened part of the material to be fastened. SOLUTION: This locking nut has a structure provided with a nut body 2, a female screw part 3 formed on the nut body 2 toward the bearing surface 2b side from the upper surface 2a side of the nut body 2, a flat surface part 4 formed on the inner peripheral wall of the nut body 2 toward the female screw part 3 side from the bearing surface 2b side, so as to have a prescribed length, and a slit part 5 formed on the flat surface part 4 as a notch toward the axial core side of the nut body 2 from the peripheral wall 2c side of the nut body 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fastening a member to be fastened by screwing with a male screw such as a bolt, and a screwing and fastening force when an external force such as vibration is applied to the member or bolt. The present invention relates to a locking nut capable of preventing a decrease in the diameter.

[0002]

2. Description of the Related Art Conventionally, bolts and nuts are frequently used to fasten various parts in transportation equipment such as automobiles, airplanes and trains, various industrial machines and equipment, transfer pipelines and power transmission devices such as electric power. In addition, bolts and nuts are of great importance as mechanical elements used for fastening various fastening parts. However, conventionally, nuts screwed to the male screw of the bolt are loosened due to external force such as vibration applied to the member to be fastened with the bolt and nut, the bolt, etc., and the screwing force and the fastening force are reduced, so that the bolt is fastened. Trouble that the fastening part of the member is loosened, the nut screwed to the bolt comes off and the fastening part of the member to be fastened comes off, and in order to improve the safety of the fastening part of the member to be fastened,
There has been a demand for a bolt or nut that prevents the nut from being loosened from the bolt due to external force such as vibration applied to the member to be fastened or the bolt.

For this reason, in recent years, various bolts and nuts have been developed in order to prevent the nut from loosening from the bolt. In particular, the following are disclosed as locking nuts for preventing the nut from loosening. Have been. JP-A-8-
No. 14241 (hereinafter referred to as “A”) discloses an upper nut and a lower tightening nut, in which an annular portion is integrally formed below the upper nut portion, and the outer circumference of the annular portion is reduced in diameter downward. In addition to forming a male taper, a continuous internal screw is engraved inside the cylindrical portion of the upper nut portion and the annular portion, and one or more horizontal split grooves are inserted in the upper portion of the annular portion, and this By providing a vertical split groove communicating with one end of the horizontal split groove, a resilient projecting element is formed, while the male taper is compressed on the outer periphery of the concave portion formed on the upper inner peripheral portion of the lower tightening nut. A lock nut having such a female taper is disclosed.

Japanese Patent Application Laid-Open No. 11-2227 (hereinafter referred to as “B”) discloses that a lower surface of a nut provided with a screw hole penetrating a shaft core is formed into a gentle inclined surface which is inclined in one direction. Is set within an angle range in which the inclined surface can press against the upper surface of the member to be tightened when the nut is screwed into the bolt and tightened to the member to be tightened with a predetermined torque. A nut is disclosed.

[0005] Japanese Patent Application Laid-Open No. 2000-27838 (hereinafter, referred to as
Japanese Unexamined Patent Publication (Kokai) Publication No. H11-27139) discloses a loosening nut which engages with a screw of a bolt, and has an eccentric screw block which engages with the screw of the bolt but is eccentric with respect to the axis of the nut body. A locking nut is disclosed.

[0006]

However, the conventional locking nut has the following problems.

[0007] In Japanese Patent Application Laid-Open Publication No. Hei 11-260, an upper nut having a male tapered annular portion formed at the lower portion having horizontal and vertical split grooves at an upper portion, and a female tapered recess formed at an upper inner peripheral portion. The upper nut and the lower tightening nut have a complicated structure, and the workability of forming the upper nut and the lower tightening nut is poor. It is easy to cause high cost of the lock nut. In addition, since the upper nut and the lower tightening nut consist of an upper nut and a lower tightening nut, the lower nut is fastened to the bolt, and then the upper nut is screwed into the upper nut to fasten the bolt and the nut. It requires two members of the nut and two tightening operations, and lacks fastening workability. Furthermore, if a large vibration load is applied to the member after the member is fastened with the locking nut, the bolt itself expands or the thread of the bolt bends, so that the lower tightening nut is momentarily separated from the member. As a result, a force is applied momentarily in a direction in which the lower tightening nut or the upper nut is loosened, and the screwing force between the bolt and the lower tightening nut or the upper nut is reduced.

According to Japanese Patent Application Laid-Open Publication No. H08-27139, if a large vibration load is applied to the member to be tightened after the member to be tightened is fastened with the locking nut, the bolt itself expands or the screw thread of the bolt bends. Due to the repetitive phenomenon in which the locking nut instantaneously separates from or adheres to the tightened member, a force is applied in the direction in which the locking nut is loosened, the screwing force between the bolt and the locking nut is reduced, and the locking effect for a long time is reduced. When the member to be tightened is subjected to a lot of vibrations, the locking nut is more likely to be loosened and the reliability of the locking is lacking. Also, since the member to be tightened is fastened by bringing the inclined surface formed on the lower surface of the lock nut into contact with the upper surface of the member to be tightened, the lock nut instantly separates from or adheres to the member to be tightened. When a repetitive phenomenon occurs, the locking nut is likely to rotate in the loosening direction,
It is difficult to maintain a long-term locking effect.

In Japanese Patent Application Laid-Open Publication No. H08-27139, after the eccentric screw block is inserted into the concave portion of the nut main body, the locking portion of the nut main body is tilted to lock the eccentric screw block in the concave portion of the nut main body. The structure of the nut is complicated and lacks productivity, and the cost of the slack nut tends to increase. In addition, since the concave portion is formed in the nut main body and the eccentric screw block is inserted into the concave portion, the nut main body becomes large, and it is difficult to reduce the size of the loosening nut. Further, since the screw of the nut body and the screw of the eccentric screw block are eccentric, the force required for tightening the slack nut is increased, and the workability for tightening is lacking. The thread of the bolt is easily damaged, and the bolt is apt to be fatigued.

An object of the present invention is to solve the above-mentioned conventional problems, to provide a simple structure which is excellent in productivity and to prevent a decrease in screwing force when an external force such as vibration is applied to a member to be fastened or a bolt. It is an object of the present invention to provide a locking nut which can maintain a high fastening force for a long period of time, greatly improve the safety of a fastening portion of a member to be fastened, and have excellent fastening workability.

[0011]

In order to solve the above-mentioned conventional problems, a locking nut according to the present invention has the following configuration.

According to a first aspect of the present invention, there is provided a locking nut, comprising: a nut main body; and a female screw portion formed on an inner peripheral wall of the nut main body with a predetermined length from an upper surface side to a seating surface side of the nut main body. A predetermined length is formed on the inner peripheral wall of the nut main body from the seating surface side of the nut main body to the female screw side with a diameter equal to or larger than the root diameter of the female screw part. And a slit portion formed by notching a predetermined depth from the outer peripheral wall of the nut main body toward the axis of the nut main body.

Accordingly, the following functions are provided. (1) Since the slit portion is provided in the flat portion formed on the seat surface side of the nut main body, the locking nut is screwed into a male screw such as a bolt when fastening the member to be fastened, and the seat surface is tightened. After being brought into contact with the member to be fastened, by further tightening the locking nut, the nut body above the slit portion can be bent and tilted toward the slit portion side. The gap (backlash) formed at the threaded portion between the female screw portion and the male screw on the upper surface side and the seating surface side of the locking nut can be eliminated, so that the female screw portion and the male screw can be brought into close contact with each other. A strong frictional force can be obtained with the screw, and it is possible to reliably prevent the locking nut from loosening from the male screw such as a bolt due to vibration or the like, and to reduce the screwing force. (2) The locking nut is screwed onto a male screw such as a bolt,
Since the nut body above the slit part is bent toward the slit part side, the female screw part of the nut body can be firmly adhered to the male screw by the reaction force due to the bending, and the locking nut and the bolt Can be further improved, and the locking nut can be more reliably prevented from loosening from the male screw such as a bolt due to external force such as vibration. (3) Since the nut body has a flat portion on the seating surface side and a slit portion is formed in the flat portion, the locking nut and the bolt are prevented from being cut in the middle of the female screw portion by the slit portion. The engagement length of the female screw portion necessary for screwing with the like can be reliably maintained, and the tensile strength and shearing force of the female screw portion when the locking nut is screwed to a male screw such as a bolt. Can be maintained. (4) Since the flat portion of the nut main body is formed to have the same diameter as the root diameter of the female screw portion or a diameter larger than the root diameter of the female screw portion, when the locking nut is screwed onto a male screw such as a bolt. In addition, the locking nut can be smoothly screwed on without the flat portion coming into contact with the outer diameter of the male screw.

Here, as the nut body, nuts of various shapes such as a polygonal nut such as a square or hexagon, a nut with a flange, and a cap nut are used. As the female screw portion, depending on the male screw to which the locking nut is screwed, a triangular screw shape such as a metric screw or an inch screw, or a trapezoidal screw shape,
And it is formed at a pitch corresponding to the male screw. Further, as the length of the female screw portion, an engagement length necessary for screwing with the male screw is obtained according to the material of the locking nut and the material of the male screw to which the locking nut is screwed. It is formed with the length which is set. The slit portion is formed at right angles to the axis of the nut main body, or is formed to be inclined with respect to the axis of the nut main body. When the slit portion is formed to be inclined with respect to the axis of the nut main body, the nut main body above the slit portion is easily bent toward the slit portion side, so that the tightening workability of the locking nut can be improved. Also, thin the seat side,
When the slit portion is formed by thickening the axial side, a reaction force is easily obtained, and a strong reaction force can be obtained with a weak fastening force.
Furthermore, the slit is opened at the open end (on the outer peripheral wall side of the nut body).
It may be formed parallel to the seating surface of the nut main body from the bottom to the bottom, or may be formed such that the open end side is expanded from the bottom side.
When the opening end side of the slit portion is formed so as to expand from the bottom side, the nut body above the slit portion is easily bent to the slit portion side, so that the tightening workability of the locking nut can be improved and a strong reaction force is obtained. And the fastening force of the locking nut can be improved.

According to a second aspect of the present invention, there is provided the locking nut according to the first aspect, wherein an inner peripheral wall of the nut main body has the same root diameter as the female screw portion or a root diameter of the female screw portion. An upper flat portion formed with a larger diameter and having a predetermined length from the upper surface side of the nut main body; and a notch having a predetermined depth formed in the upper flat surface portion from the outer peripheral wall side of the nut main body toward the axis of the nut main body. And an upper slit portion formed.

Thus, the following operation is obtained in addition to the operation of the first aspect. (5) Conventionally, a male screw such as a bolt is screwed into a male screw such as a bolt so that the seat surface side of the locking nut comes into contact with a member to be fastened, and a screw such as a bolt contacts the upper surface of the locking nut. When the nut is screwed and the fastened member is fastened (the fastened member is fastened with a double nut with the locking nut as the power nut and the conventional nut as the lock nut),
By the nut on the upper surface side of the locking nut, the nut body above the upper slit portion of the locking nut can be bent and inclined toward the upper slit portion side. As a result, the slit portion and the upper slit portion can be tilted. In both cases, the gap (backlash) formed at the threaded portion between the female screw portion and the male screw of the locking nut can be absorbed, and the female screw portion and the male screw can be brought into close contact with each other. A strong frictional force can be obtained, and it is possible to reliably prevent the locking nut from loosening from a male screw such as a bolt due to vibration or the like and to reduce the screwing force, thereby improving the fastening force.

Here, it is preferable that the upper slit is formed at a point symmetrical position with respect to the slit. As a result, both the slit portion and the upper slit portion can absorb the backlash formed in the female screw portion located symmetrically with respect to the axis of the nut main body as a center, and more firmly bolt the locking nut. And so on. Also,
The upper slit portion is formed at right angles to the axis of the nut main body, or is formed to be inclined with respect to the axis of the nut main body. Further, the upper slit portion may be formed in parallel from the opening end (the outer peripheral wall side of the nut main body) to the bottom, or the opening end may be formed so as to expand from the bottom.
Depending on the material of the locking nut, the material of the male screw to which the locking nut is screwed, etc., the engagement length required for screwing with the male screw from the lower end side of the upper flat portion is used as the female screw portion. Is formed in a length that can obtain the following.

According to a third aspect of the present invention, in the lock nut according to the first or second aspect, the length of the flat portion and the upper flat portion is 1/1 / the pitch of the female screw portion. It has a configuration that is twice or more.

Thus, the following operation is obtained in addition to the operation of the first or second aspect. (6) Since the lengths of the flat portion and the upper flat portion are formed at least half the pitch of the female screw portion, a slit portion or an upper slit portion can be formed in the flat portion or the upper flat portion, and the flat portion or the upper flat portion can be formed. The backlash formed in the threaded portion of the female screw and the male screw can be absorbed by the slit and the upper slit formed in the portion and the upper flat portion, and the female screw of the locking nut is replaced with a bolt or the like. It can be securely screwed in close contact with the male screw.

Here, depending on the material and size of the locking nut, the pitch of the female screw portion, etc., the length of the flat portion and the upper flat portion is shorter than 1/2 times the pitch of the female screw portion. As it becomes difficult to form a slit portion or an upper slit portion in a flat portion or an upper flat portion, the width of the slit portion or the upper slit portion becomes too narrow, and the female screw of the locking nut is formed in the slit portion or the upper slit portion. The backlash formed in the threaded portion between the threaded part and the male screw such as a bolt tends to be unable to be absorbed. Therefore, the length of the flat part and the upper flat part should be 1/2 or more times the pitch of the female screw part, and Any length may be used as long as the slit and the upper slit can be formed in a size large enough to absorb the backlash between the screw and the male screw. The length of the flat portion and the upper flat portion is preferably 1/2 to 100 times the pitch of the female screw portion, although it depends on the size of the pitch of the female screw portion. As the length of the flat portion and the upper flat portion becomes larger than 100 times the pitch of the female screw portion, the flat portion,
The length of the upper flat portion is unnecessarily long, and the locking nut tends to be large.

According to a fourth aspect of the present invention, there is provided the locking nut according to any one of the first to third aspects, wherein the nut has a top surface on a slit portion of an inner wall of the slit portion from a seating surface of the nut body. The length from the upper surface of the nut body to the lower surface of the slit portion of the inner wall of the upper slit portion is not more than one time the length of the upper flat portion. It has the structure formed by.

Thus, in addition to the functions of the first to third aspects, the following functions are provided. (7) The locking nut is screwed onto a male screw such as a bolt,
When the seat surface is brought into contact with the member to be fastened and the locking nut is further tightened, or the nut is screwed into a male screw such as a bolt so that the nut comes into contact with the upper surface side of the locking nut, When the seat surface of the nut is brought into contact with the upper surface side of the locking nut and tightened, the nut body above the slit portion or the upper slit portion can be sufficiently bent and inclined toward the slit portion or the upper slit portion side. It is possible to eliminate the gap (backlash) formed at the threaded portion between the female screw portion and the male screw of the nut body and to make the female screw portion and the male screw adhere to each other to obtain a strong frictional force between the female screw portion and the male screw. Can be. (8) Since the nut main body above the slit portion and the upper slit portion can be sufficiently bent toward the slit portion and the upper slit portion, a reaction force due to the bending can be sufficiently obtained. The female screw portion can be firmly adhered to the male screw, and the locking nut can be more reliably prevented from loosening from the male screw such as a bolt due to external force such as vibration.

Here, depending on the material and size of the locking nut, the width and depth of the slit portion and the upper slit portion, the formation positions of the slit portion and the upper slit portion (from the seating surface of the nut body to the slit). When the length from the upper surface of the nut portion to the lower surface of the slit portion is greater than one time the length of the flat portion, the slit portion and the upper slit portion are formed in the female screw portion. The engagement length required for screwing the locking nut is not obtained, and the screwing force tends to decrease. The slit portion and the upper slit portion are preferably formed at positions 1/10 to 1 times the length of the flat portion from the seat surface side and the upper surface side of the nut body, depending on the length of the flat portion. Is done. As the length of the flat portion becomes shorter than 1/10, the thickness from the seat surface of the nut body to the lower surface of the slit portion and from the upper surface of the nut body to the upper surface of the slit portion becomes thinner. When the nut is tightened, the seat surface side and the upper surface side of the nut main body tend to buckle easily at the slit portion and the bottom side of the upper slit portion.

According to a fifth aspect of the present invention, there is provided the locking nut according to any one of the first to fourth aspects, wherein the length from the opening end to the bottom of the slit is the opening. The length from the end to the flat portion is not less than 99/100 times the maximum outer diameter of the nut body, and the length from the opening end to the bottom of the upper slit is from the opening end to the top. It is formed and formed to have a length not less than the length to the flat portion and not more than 99/100 times the maximum outer diameter of the nut body.

Thus, in addition to the functions of claims 1 to 4, the following functions are provided. (9) The length from the opening end of the slit to the bottom (the depth of the slit) is the length from the opening end of the slit (the outer peripheral wall of the nut body) to the plane (the thickness of the plane). that's all,
The length from the opening end of the upper slit to the bottom (depth of the upper slit) is 99/100 times or less of the maximum outer diameter of the nut main body, and the opening end of the upper slit (the outer peripheral wall of the nut main body) The length of the nut from the upper part to the upper flat part (thickness of the upper flat part) is not less than 99/100 times the maximum outer diameter of the nut body, so the locking nut is tightened to a male screw such as a bolt, When bending the nut body above the slit portion and the upper slit portion toward the slit portion and the upper slit portion, the work can be easily tightened without requiring a large tightening torque. It can be bent sufficiently to the side.

Here, depending on the material of the locking nut and the width of the slit portion, if the depth of the slit portion and the upper slit portion is smaller than the thickness of the flat portion and the upper flat portion of the nut body, the depth of the nut is reduced. When tightening the lock nut, a large torque is required to bend the nut body above the slit and upper slit to the slit and upper slit, and the nut cannot be sufficiently bent. There is a tendency that the backlash formed in the screw portion of the female screw portion and the male screw cannot be absorbed by the slit portion and the upper slit portion. As the nut becomes deeper than 99/100 times the maximum outer diameter of the nut body, the slit portion becomes larger. And the wall thickness from the bottom of the upper slit to the outer peripheral wall of the nut body is reduced, and the nut body below the slit and above the upper slit is Easily buckled bottom side of the isolation portion,
The locking nut tends to lack durability. Note that, depending on the material of the lock nut and the size of the lock nut, etc., the slit portion and the upper slit portion are separated from the outer peripheral wall of the nut body by a flat portion around the axis of the nut body and an upper flat surface. It is preferable to form it up to a position of ± １ ／ times the inner diameter of the part. As a result, the nut body above the slit portion or the upper slit portion can be sufficiently bent without requiring a large tightening torque to the slit portion or the upper slit portion side, and the locking nut is excellent in usability. The backlash formed at the threaded portion between the female screw portion and the male screw of the lock nut can be absorbed to reliably prevent the lock nut from loosening. Further, a reduction in stress resistance due to buckling can be prevented, and durability can be improved.

[0027]

(Embodiment 1) A locking nut according to Embodiment 1 of the present invention will be described below with reference to the drawings.

FIG. 1A is an overall perspective view of the locking nut according to the first embodiment, and FIG. 1B is a perspective view of FIG.
FIG. 4 is a sectional view taken along line AA of FIG. In FIG. 1, reference numeral 1 denotes a hexagon nut-shaped locking nut according to the first embodiment, 2 denotes a nut body of the locking nut 1, 2a denotes an upper surface of the nut body 2, 2b denotes a bearing surface of the nut body 2, and 2c denotes a nut body. 2 is an internal thread portion formed on the inner peripheral wall of the nut main body 2 by a predetermined length from the upper surface 2a side of the nut main body 2 toward the seating surface 2b side; The bearing surface 2b has a diameter substantially equal to or slightly larger than the valley diameter of the portion 3.
A flat portion 5 formed toward the female screw portion 3 from the outer peripheral wall 2c of the nut main body 2 toward the axial center side of the nut main body 2; 5
a is the opening end of the slit 5; 5b is the bottom of the slit 5; 5c is the upper surface of the slit on the inner wall of the slit 5;
Is the lower surface of the slit portion on the inner wall of the slit portion 5. In the drawing, p is the pitch of the female screw portion 3, L is the length of the flat portion 4 (the length from the seating surface 2b to the female screw portion 3), and h is the slit portion 5.
, W is the depth of the slit portion 5 (the length from the opening end portion 5a to the bottom portion 5b of the slit portion 5), t is the length from the seating surface 2b to the slit portion upper surface 5c of the slit portion 5, and c is The maximum outer diameter of the nut body 2 is shown.

Here, in the first embodiment, the length L of the flat portion 4 is formed to be at least half the pitch p of the female screw portion 3. Further, the length t from the seating surface 2b to the slit portion upper surface 5c of the slit portion 5 is formed to be not more than one time the length L of the flat portion 4. Further, the depth w of the slit portion 5 is formed not less than the thickness of the flat portion 4 (thickness from the outer peripheral wall 2c to the flat portion 4) and not more than 99/100 times the maximum outer diameter c of the nut main body 2.

The use state of the locking nut according to the first embodiment configured as described above will be described below with reference to the drawings. FIG. 2 is a sectional view of an essential part showing a state in which the locking nut according to the first embodiment is screwed into a bolt via a member to be fastened, and FIG. 3 fastens the member to be fastened with the locking nut according to the first embodiment. It is principal part sectional drawing which shows the state which carried out. In the figure, 6 is a bolt, 7 is a male screw of the bolt 6, 8
Reference numerals a and 8b denote members to be fastened to the bolt 6 with the locking nut 1, and reference numeral 9 denotes a bolt hole formed in the members to be fastened 8a and 8b and through which the bolt 6 is inserted. In the drawing, B indicates a gap (backlash) formed in the threaded portion between the female screw portion 3 and the male screw 7 when the locking nut 1 is screwed into the bolt 6. Here, as the bolt 6, the male screw 7 has the female screw 3 at the same pitch p as the pitch p of the female screw 3 of the locking nut 1.
Is used.

When the members to be fastened 8a and 8b are fastened to the bolts 6 with the locking nuts 1, the bolts 6 are inserted into the bolt holes 9 of the members to be fastened 8a and 8b, and as shown in FIG. Is screwed into the male screw 7 of the bolt 6 to bring the seat surface 2b of the locking nut 1 into contact with the surface of the member 8a to be fastened. Next, when the locking nut 1 is further tightened, as shown in FIG. 3, the female screw portion 3 is screwed to the male screw 7 and the nut main body 2 above the slit portion 5 is bent toward the slit portion 5 side. The nut body 2 above the slit portion 5 is inclined toward the opening end 5a of the slit portion 5. When the nut body 2 above the slit portion 5 is inclined toward the opening end 5a of the slit portion 5, as shown in FIG.
Female screw 3 and male screw 7 on the opening end 5a side of the slit 5
(The X part in the figure), the backlash B of the threaded portion of the female screw part 3 on the upper surface 2a side and the male screw 7 (the Y part in the figure) symmetrically with the opening end part 5a are respectively in close contact, and the members 8a 8b is fastened.

As described above, since the locking nut according to the first embodiment is configured, it has the following operation. (1) Since the slit portion is provided in the flat portion formed on the seat surface side of the nut body, the locking nut is screwed into the male screw of the bolt, and the seat surface is brought into contact with the member to be fastened. Thereby, the female screw part of the locking nut and the male screw of the bolt can be screwed, and the nut body above the slit part can be bent by bending toward the slit part side, and can be inclined.
As a result, the backlash formed at the threaded portion between the female screw portion and the male screw on the upper surface side and the seat surface side of the locking nut can be eliminated, and the female screw portion and the male screw can be brought into close contact with each other. It is possible to reliably prevent the locking nut from loosening from the male screw due to external force such as vibration applied to a bolt or the like. (2) When the locking nut is tightened, the nut body above the slit bends toward the slit side, and the female screw of the nut body is firmly adhered to the male screw by the reaction force due to the bending. This enhances the adhesion and friction between the female screw and the male screw. As a result, even when the bolt is bent due to the external force of vibration applied to the member to be fastened or the bolt, the female screw and the male screw can be in close contact with each other. The screwing force between the locking nut and the bolt can be further improved without reducing the force. (3) Since the nut body has a flat surface portion on the seat surface side and a slit portion is formed in the flat surface portion, the screw thread of the female screw portion is not cut by the slit portion, and the locking nut and the bolt are not cut. The required engagement length of the female screw portion required for screwing with the screw can be secured, and the tensile strength and shearing force when the locking nut and the bolt are screwed together can be maintained. (4) Since the flat portion of the nut main body is formed with a diameter substantially equal to or slightly larger than the root diameter of the female screw portion, the screw is smoothly screwed into the bolt when the female screw portion is screwed. be able to. (5) Since the length of the flat portion is formed at least half the pitch of the female screw portion, a slit portion can be formed in the flat portion, and the female screw portion and the male screw are formed by the slit portion. The backlash of the threaded portion can be absorbed. (6) Since the length from the seating surface to the upper surface of the slit portion is less than one time the length of the flat portion and is formed in the flat portion, the nut body above the slit portion is sufficiently bent toward the slit portion side. Further, the reaction force due to the deflection can be sufficiently obtained, the female screw portion can be more firmly brought into close contact with the male screw, and the locking nut is prevented by external force such as vibration applied to a member to be fastened or a bolt. Can be reliably prevented from loosening from the bolt. (7) The depth of the slit portion is not less than the length from the outer peripheral wall of the nut main body to the flat portion, and is 99/1 of the maximum outer diameter of the nut main body.
Since it is formed at a magnification of 00 or less, when tightening the locking nut to the bolt to bend the nut body above the slit portion toward the slit portion, a large tightening torque is not required, and the tightening operation can be easily performed. .

(Embodiment 2) In Embodiment 2 in which the locking nut according to Embodiment 1 of the present invention is used as a lock nut, a loosening test thereof will be described with reference to the drawings. FIG. 4A is a side sectional view of a main part showing a loosening test state when the locking nut according to the first embodiment is used as a lock nut, and FIG. 4B is a sectional view illustrating the locking nut according to the first embodiment. It is a front view which shows the looseness test state at the time of using as a lock nut. In the figure, 1
0 is a NASA-type high-speed screw looseness tester, 11 is a vibrating table vibrated in the vertical direction, 12 is a mounting jig installed on the vibrating table 11, 12a is a long hole formed in the mounting jig 12, 1
Reference numeral 3 denotes a cylindrical vibrating barrel which is vertically movably inserted into the long hole portion 12a of the mounting jig 12, 14 denotes a bolt inserted through the vibrating barrel 13, and 15 denotes a screw which is screwed to the bolt 14 via the vibrating barrel 13. A conventional nut 16 used as a power nut is a washer which is fitted on the bolt 14 and is located between the nut 15 and the vibrating barrel 13. In the figure, S is the distance (impact stroke) between the upper end of the outer peripheral surface of the vibrating barrel 13 and the upper end of the elongated hole 12a, and is 1 in the NASA-type high-speed screw looseness tester 10 of the second embodiment.
9 mm is used.

Here, the nut 1 is a nut having a M16 size, a maximum outer diameter c of the nut body 2 of 27.7 mm, and a pitch p of the female screw portion 3 of 1 m.
m, the length of the flat portion 4 (the length from the bearing surface 2b to the female screw portion 3) L is 5 mm, the width h of the slit portion 5 is 1 mm, and the bearing surface 2
The length t from b to the slit upper surface 5c of the slit 5
Is 4 mm. Further, the depth w of the slit portion 5 (the length from the opening end 5a to the bottom portion 5b of the slit portion 5) w is formed to be the depth from the outer peripheral wall 2c of the nut main body 2 to the axis of the nut main body 2. (Hereinafter referred to as a specimen 1), formed 5 mm deeper than the axis of the nut body 2 from the outer peripheral wall 2c (hereinafter referred to as test specimen 2), and formed 5 mm shallower than the axis of the nut body 2 from the outer peripheral wall 2c. (Hereinafter referred to as "test body 3"), a looseness test was performed. As shown in FIG. 4, the locking nut 1 screwed to the bolt 14 and tightened is the same as that of the first embodiment.
As shown in FIG. 3, the backlash of the threaded portion between the male screw of the bolt 14 and the female screw portion 3 of the locking nut 1 is absorbed by the slit portion 5 and is in close contact.

Using the NASA-type high-speed screw looseness tester 10 configured as described above, a test method of a looseness test when each of the lock nuts 1 of the test pieces 1 to 3 is used as a lock nut will be described. This will be described below. FIG.
As shown in the figure, the nut 15 is a power nut, and each of the locking nuts 1 of the test pieces 1 to 3 is a lock nut.
It is screwed to a bolt 14 attached to a NASA-type high-speed screw looseness tester 10. Next, the vibration table 11 was set at a vibration acceleration of 19.5 G, a vibration stroke of 11 mm, and a vibration frequency of 178.
0c. p. vibrating up and down at m for 17 minutes, and measuring the loosening torque of the locking nut 1 after vibration of each of the test pieces 1 to 3. Here, the reason for applying the vibration by the vibrating table 11 for 17 minutes is to meet the passing criteria of the NASA looseness test. Note that the locking nuts 1 of the test pieces 1 to 3 each have a fastening torque of 7 kg · m
It is screwed in.

Specimens 1 to 3 in the above loosening test
The results of the loosening test of the locking nut 1 will be described below. In the specimen 1 in which the slit portion 5 is formed at a depth from the outer peripheral wall 2c of the nut main body 2 to the axis of the nut main body 2, the loosening torque after the loosening test is 8 kg · m, and the slit portion 5 In the test body 2 formed 5 mm deeper than the axis of the nut body 2 from the outer peripheral wall 2c, the loosening torque after the loosening test is 7 kg · m,
In the test piece 3 formed from the outer peripheral wall 2c of the nut main body 2 to be 5 mm shallower than the axis of the nut main body 2, the loosening torque after the looseness test is 7 kg · m, and all of the test pieces 1 to 3 No looseness or displacement was found.
The looseness test in the NASA-type high-speed screw looseness tester 10 is the same as the NASA looseness test method. Based on the results of this looseness test, all of the locking nuts 1 of the test specimens 1 to 3 pass the NASA acceptance criteria ( Vibration acceleration19.
5G, vibration stroke 11mm, frequency 1780c.
p. m (fastening force that can withstand vertical vibration for 17 minutes at m).

As described above, the second embodiment in which the locking nut in the first embodiment is used as a lock nut.
Then, in addition to the operation described in the first embodiment, even when used as a lock nut, it is possible to eliminate the backlash of the screwing portion between the female screw portion of the locking nut and the male screw of the bolt, and to make the nut tightly adhered. As a result, it is possible to obtain a high fastening force exceeding the NASA acceptance criteria, and even if an external force such as vibration is applied to the bolt or the locking nut, the fastening force does not decrease, and the high fastening force is maintained for a long time. Can be maintained.

Embodiment 3 A locking nut according to Embodiment 3 of the present invention will be described below with reference to the drawings.

FIG. 5 is an overall perspective view of a locking nut according to the third embodiment. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In FIG. 5, reference numeral 20 denotes a locking nut according to the second embodiment, reference numeral 21 denotes a slit portion formed by notching a predetermined depth from the outer peripheral wall 2 c of the nut main body 2 toward the axis of the nut main body 2, 2
1a is an opening end of the slit 21 and 21b is a bottom of the slit 21. In addition, w 'indicates the depth of the slit portion 21 (the length from the opening end 21a to the bottom portion 21b of the slit portion 21), and the thickness of the flat portion 4 of the nut body 2 (from the outer peripheral wall 2c to the flat portion 4). The thickness is not less than 99/100 times the maximum outer diameter c of the nut body 2.

The use state of the locking nut according to the third embodiment configured as described above will be described below with reference to the drawings. FIG. 6 is a cross-sectional view of a main part showing a state where a member to be fastened is fastened using a locking nut as a power nut and a conventional nut as a lock nut in the third embodiment.
In FIG. 6, reference numeral 22 denotes a conventional nut screwed onto the male screw 7 of the bolt 6 and located above the locking nut 20. Here, in the third embodiment, the upper surface 2a of the locking nut 20 is brought into contact with the member to be fastened 8a, and the locking nut 20 is screwed so that the seating surface of the nut 22 comes into contact with the seating surface 2b. However, the locking nut 20 may be screwed so that the seating surface 2b of the locking nut 20 abuts on the member 8a to be fastened and the seating surface of the nut 22 abuts on the upper surface 2a.

The locking nut 20 according to the third embodiment is different from the locking nut 1 according to the first embodiment in the cutout position of the slit portion 21. The locking nut 20 according to the third embodiment is different from the locking nut 20 according to the third embodiment. It can be used in the same manner as the lock nut 1 of the first embodiment, and the same action can be obtained. Also, as described in Embodiment 3,
The locking nut of the present invention can be used as a power nut, has a strong screwing force, and has the effect of improving the usability of the locking nut.

(Embodiment 4) A locking nut according to Embodiment 4 of the present invention will be described below with reference to the drawings.

FIG. 7 (a) is an overall perspective view of a locking nut according to Embodiment 4, and FIG. 7 (b) is FIG. 7 (a).
It is CC sectional view taken on the line of FIG. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In FIG. 7, reference numeral 30 denotes a hexagon nut-shaped locking nut according to the fourth embodiment, 3 ′ denotes a female screw portion having a predetermined length formed on the inner peripheral wall of the nut main body 2, and 4 ′ denotes a female screw on the inner peripheral wall of the nut main body 2. An upper flat portion formed from the upper surface 2a side of the nut main body 2 to the upper end portion of the female screw portion 3 'with substantially the same diameter as the root diameter of the screw portion 3';
Reference numeral 5 'denotes an upper slit portion 5' formed by notching a predetermined depth from the outer peripheral wall 2c of the nut main body 2 toward the axis of the nut main body 2 at a position symmetrical to the slit portion 5 in the upper flat portion 4 '.
a is the opening end of the upper slit 5 ', 5'b is the bottom of the upper slit 5', 5'c is the upper surface of the slit on the inner wall of the upper slit 5 ', and 5'd is the upper end of the upper slit 5'. It is a slit part lower surface of an inner wall.

In the drawing, L 'is the length of the upper flat portion 4' (the length from the upper surface 2a to the female screw portion 3), h 'is the width of the upper slit portion 5', and w 'is the upper slit portion. 5 'depth (from the opening end 5'a of the upper slit 5' to the bottom 5'b
), T 'is from the upper surface 2a to the upper slit portion 5'.
Shows the length up to the slit portion lower surface 5'd. Here, in the fourth embodiment, the upper slit portion 5 ′ is formed at a point-symmetric position with respect to the slit portion 5 about the axis of the nut main body 2, and the length L of the flat portion 4 and the upper flat portion 4 'Length L',
The width h of the slit 5 and the width h 'of the upper slit 5', the depth w of the slit 5 and the depth w 'of the upper slit 5',
The length t from the seating surface 2b to the slit portion upper surface 5c of the slit portion 5 and the length t 'from the upper surface 2a to the slit portion lower surface 5'd of the upper slit portion 5' are formed to have the same size. Further, in the fourth embodiment, the length L of the flat portion 4 and the length L 'of the upper flat portion 4' are formed at a half or more of the pitch p of the female screw portion 3 '. The length t of the slit portion 5 from the upper surface 5c to the slit portion upper surface 5c and the length t 'from the upper surface 2a to the slit portion lower surface 5'd of the upper slit portion 5' are the length L of the flat portion 4 and the length of the upper flat portion 4 '. The depth w of the slit portion 5 and the depth w 'of the upper slit portion 5' are equal to or less than the length L ', and the thickness of the flat portion 4 and the thickness of the upper flat portion 4' (from the outer peripheral wall 2c to the flat portion 4, the thickness up to the upper flat portion 4 ') and not more than 99/100 times the maximum outer diameter c of the nut body 2.

The use state of the locking nut according to the fourth embodiment configured as described above will be described below with reference to the drawings. FIG. 8 is a cross-sectional view of a main part showing a state where a member to be fastened is bolted with a locking nut as a power nut in the fourth embodiment. Embodiments 1 and 3
The same components as those described above are denoted by the same reference numerals, and description thereof is omitted.

When the members to be fastened 8a and 8b are fastened with a double nut having the locking nut 30 as a power nut and the conventional nut 22 as a lock nut, the members 8a and 8b are fastened.
8, the bolt 6 is inserted into the bolt hole 9, and as shown in FIG. 8, the locking nut 30 is screwed into the male screw 7 of the bolt 6 so that the seating surface 2 b of the locking nut 30 is the surface of the member 8 a. Then, the nut 22 is screwed into the bolt 6, and the seat surface of the nut 22 is brought into contact with the upper surface 2 a of the nut 30. Next, the locking nut 30 is further tightened and the nut 22 is further tightened. As shown in FIG. 8, the nut body 2 above the slit portion 5 of the locking nut 30 is bent toward the slit portion 5 side, and The nut body 2 above the portion 5 'is bent toward the upper slit portion 5'. Here, when the nut body 2 above the slit portion 5 and the nut body 2 above the upper slit portion 5 'are inclined toward the opening ends 5a and 5'a of the slit portion 5 and the upper slit portion 5', respectively, FIG. As shown in FIG. 8, the backlash of the threaded portion of the female screw 3 ′ of the locking nut 30 and the male screw 7 of the bolt 6 comes into close contact, and the members to be fastened 8 a, 8
b is firmly fastened.

As described above, since the locking nut according to the fourth embodiment is configured, it has the following operation in addition to the operation of the first to third embodiments. (1) Since the nut body has an upper flat portion and an upper slit portion on the upper surface side, when the member to be fastened is fastened with a double nut using the locking nut as a power nut and the conventional nut as a lock nut. The nut body above the upper slit portion can be bent by the nut toward the upper slit portion. As a result, the female screw portion of the locking nut and the male screw of the bolt can be bent at both the slit portion and the upper slit portion. The backlash formed in the threaded portion can be absorbed, and the female screw portion and the male screw can be closely contacted and screwed together, and the locking nut is loosened from the male screw such as a bolt due to vibration or the like. This can be reliably prevented from lowering, and the fastening force can be significantly improved. (2) Since the upper surface side of the nut main body has an upper flat portion and an upper slit portion, the locking nut can be used as a power nut of a double nut, so that versatility can be improved and fastening with the double nut can be performed. The force can be improved, and the reliability of the fastening force can be improved.

[0048]

As described above, according to the lock nut of the present invention, the following excellent effects can be realized.

According to the first aspect of the present invention, (1) since the flat portion formed on the seat surface side of the nut main body is provided with the slit portion, when the member to be fastened is fastened, the loosening is prevented. The nut is screwed into a male screw such as a bolt to bring the seat surface into contact with the member to be fastened, and further tightening the locking nut causes the nut body above the slit to be bent and tilted toward the slit. As a result, particularly, the backlash formed at the threaded portion between the female screw portion and the male screw on the upper surface side and the seat surface side of the locking nut is eliminated, and the female screw portion and the male screw are brought into close contact with each other. The frictional force between the female screw portion and the male screw can be remarkably improved, and the locking nut is loosened from the bolt or the like by external force such as vibration applied to the member to be fastened or the bolt, and the screwing force is reduced. Can be reliably prevented and tightened The fastening force of the fastening portion of the binding member can be improved, and the safety and reliability are excellent. (2) Since the nut for locking is tightened to a male screw such as a bolt and the nut body above the slit is bent toward the slit, the female screw of the nut main body is formed with a male screw due to the reaction force due to the bending. Can firmly adhere to each other, further improve the frictional force between the female screw portion and the male screw, and when an external force such as vibration is applied to the member to be fastened or the bolt, the bolt or the like expands or the male screw is bent. Also, the screwing force between the locking nut and the male screw can be further improved without loosening the locking nut from the male screw, and the screwing force and the fastening force of the locking nut can be maintained for a long period of time. Excellent reliability. (3) Since the nut body has a flat portion on the seating surface side and a slit portion is formed in the flat portion, the locking nut and the bolt are prevented from being cut in the middle of the female screw portion by the slit portion. The engagement length of the female screw portion necessary for screwing with the like can be secured, and even if the slit portion is formed, the female screw portion when the locking nut is screwed to the male screw such as a bolt. The tensile strength and the shearing force can be maintained. (4) The locking nut can be formed simply by forming a female screw portion on the nut body in the same manner as a conventional nut, and forming a flat portion on the seat surface side and a slit portion on the flat portion, The structure is simple and the productivity is excellent, and just by screwing one of the locking nuts onto a male screw such as a bolt,
The member to be fastened can be fastened without lowering the fastening force due to external force such as vibration, and the usability and convenience are excellent.

According to the second aspect of the present invention, the first aspect is provided.
In addition to the effect of (5), since the upper surface of the nut body has an upper flat portion and an upper slit portion, in particular, a double nut having the locking nut as the power nut and the conventional nut as the lock nut is used. When the member to be fastened is fastened, the nut body above the upper slit portion of the lock nut can be bent and inclined toward the upper slit portion side by the nut on the upper surface side of the lock nut, as a result, Both the slit portion and the upper slit portion can absorb the backlash formed at the threaded portion between the female screw portion and the male screw of the locking nut, and the locking nut can be connected to the male screw such as a bolt by vibration or the like. Can securely prevent the screwing force from lowering,
The fastening force can be further improved, and the reliability of the fastening force and the safety of the fastening portion can be significantly improved.

According to the invention described in claim 3, according to claim 1
(6) Since the lengths of the flat portion and the upper flat portion are formed at least half the pitch of the female screw portion, the slit portion and the upper portion are formed in the flat portion and the upper flat portion. The slit portion can be formed, and the backlash of the threaded portion between the female screw portion and the male screw can be absorbed by the slit portion and the upper slit portion. The locking nut is brought into close contact with the male screw of the bolt to securely screw. It can be attached and has excellent reliability of screwing force.

According to the fourth aspect of the present invention, the first aspect is provided.
In addition to the effects of (1) to (3), (7) the locking nut is screwed into a male screw such as a bolt,
When the seat surface is brought into contact with the member to be fastened and the locking nut is further tightened, or the nut is screwed into a male screw such as a bolt so that the nut comes into contact with the upper surface side of the locking nut, When the seat surface of the nut is brought into contact with the upper surface side of the locking nut and tightened, the nut body above the slit portion or the upper slit portion can be sufficiently bent and inclined toward the slit portion or the upper slit portion side. The backlash formed at the threaded portion between the female screw and the male screw of the nut body can be eliminated, and the female screw and the male screw can be firmly adhered to each other to improve the frictional force between the female screw and the male screw. It is possible to reliably prevent the locking nut from loosening from a male screw such as a bolt due to the external force, and to obtain a high locking effect. (8) Since the nut main body above the slit portion and the upper slit portion can be sufficiently bent toward the slit portion and the upper slit portion, a reaction force due to the bending can be sufficiently obtained. The female screw portion can be firmly adhered to the male screw, the locking nut can be more securely prevented from loosening from the male screw such as a bolt due to external force such as vibration, and the reliability of the locking effect is excellent, and High fastening force can be maintained for a long time, and the safety of the fastening portion is excellent.

According to the invention described in claim 5, claim 1 is provided.
In addition to the effects of (1) to (4), (9) the depth of the slit (the length from the opening end to the bottom of the slit) is equal to or greater than the length from the opening end of the slit to the flat surface, Not more than 99/100 times the outer diameter, the depth of the upper slit (the length from the open end to the bottom of the upper slit) should be greater than the length from the open end of the upper slit to the upper flat portion, and the nut Since the nut is formed to be 99/100 times or less of the maximum outer diameter of the main body, the locking nut is tightened to a male screw such as a bolt, and the nut main body above the slit portion and the upper slit portion is on the slit portion and upper slit side. When bending, the nut can be easily tightened without requiring a large amount of tightening torque, and the locking nut is excellent in usability and handling, and the nut body is sufficiently bent to the slit and upper slit sides. With And a high fastening force can be obtained.

[Brief description of the drawings]

FIG. 1A is an overall perspective view of a locking nut according to a first embodiment. FIG. 1B is a cross-sectional view taken along line AA of FIG. 1A.

FIG. 2 is an essential part cross-sectional view showing a state where the locking nut according to the first embodiment is screwed into a bolt via a member to be fastened;

FIG. 3 is an essential part cross-sectional view showing a state where the member to be fastened is fixed with the locking nut according to the first embodiment;

FIG. 4 (a) is a side sectional view of a main part showing a loosening test state when the locking nut according to the first embodiment is used as a lock nut. (B) The locking nut according to the first embodiment is used as a lock nut. Front view showing the looseness test state in case

FIG. 5 is an overall perspective view of a locking nut according to a third embodiment.

FIG. 6 is a cross-sectional view of a principal part showing a state where a member to be fastened is fastened using a locking nut as a power nut and a conventional nut as a lock nut in the second embodiment.

7A is an overall perspective view of a locking nut according to a fourth embodiment. FIG. 7B is a sectional view taken along line BB of FIG. 7A.

FIG. 8 is a cross-sectional view of a principal part showing a state in which a member to be fastened is bolted with the locking nut in the fourth embodiment as a power nut.

[Explanation of symbols]

 1, 20, 30 Lock nut 2 Nut body 2a Upper surface 2b Seat surface 2c Outer peripheral wall 3, 3 'Female screw part 4, 4' Flat part 5, 5 ', 21 Slit part 5a, 5'a, 21a Open end 5b, 5'b, 21b Bottom 5c, 5'c Slit upper surface 5d, 5'd Slit lower surface 6, 14 Bolt 7 Male screw 8a, 8b Fastened member 9 Bolt hole 10 NASA high-speed high-speed screw looseness tester 11 Shaking table 12 Mounting jig 12a Slot 13 Vibrating barrel 15, 22 Nut 16 Washer

Claims (5)

[Claims] 1. A nut body, a female screw portion formed on an inner peripheral wall of the nut main body with a predetermined length from an upper surface side of the nut main body to a seat surface side, and the female screw portion formed on an inner peripheral wall of the nut main body. A flat portion having the same diameter as the root diameter of the portion or larger than the root diameter of the female screw portion and having a predetermined length formed from the bearing surface side of the nut body toward the female screw portion side; A slit formed by cutting out a predetermined depth from the outer peripheral wall side of the main body toward the axis of the nut main body. 2. An upper flat portion formed on an inner peripheral wall of the nut main body and having a diameter equal to or larger than a root diameter of the female screw portion and having a predetermined length from an upper surface side of the nut main body. 2. An upper slit portion having a notch formed at a predetermined depth from the outer peripheral wall side of the nut main body toward the axis of the nut main body, on the upper flat surface portion. Lock nut. 3. The length of the flat portion and the upper flat portion is:
The locking nut according to claim 1, wherein the nut is formed at a half or more of a pitch of the female screw portion. 4. A length from a seating surface of the nut body to an upper surface of a slit portion of an inner wall of the slit portion is formed to be equal to or less than one time a length of the flat portion. The locking nut according to any one of claims 1 to 3, wherein a length of the inner wall to a lower surface of the slit portion is formed and is not more than one time a length of the upper flat portion. 5. A length of the slit portion from an open end to a bottom portion is equal to or greater than a length from the open end to the flat portion.
It is formed to be 99/100 times or less the maximum outer diameter of the nut body, the length from the open end to the bottom of the upper slit is not less than the length from the open end to the upper flat portion, and Formed at 99/100 times or less of the maximum outer diameter,
The locking nut according to any one of claims 1 to 4, wherein the locking nut is formed.