JP6260843B1 - Lock nut not to loosen - Google Patents

Abstract

Provided is a lock nut structure in which a screw thread of a bolt and a screw hole of a nut are forcibly brought into close contact with each other to provide a high locking effect. A plurality of vertical slits 7 are formed radially from the central axis of a screw hole 8 from the upper end to the lower end of a flanged nut, and the bottom surface 2c of the nut is screwed with a screw shaft of a bolt. A gap portion is provided around the central axis of the bottom surface of the nut so that the outer surface 2b of the bottom surface of the nut receives a pressing force from the fastening member 6 and the bottom surface 2c of the nut is deformed. When the nut having the above shape is fastened to the bolt, the screw hole 8 at the upper end of the nut is deformed to reduce the diameter toward the central axis of the screw hole, and a strong frictional resistance force is generated on the surface of the bolt and the screw hole. Further, by forming the cylindrical protrusion 4 with the center of the screw hole as an axis at the upper end of the nut and inserting the lock ring 3, the screw hole at the upper part of the nut fitted to the bolt does not expand to the original shape. Thus, it has a long-term loosening prevention effect. [Selection] Figure 1

Description

The present invention is a fastening nut for fixing various members by using bolts or implanted bolts in various mechanical devices, buildings, automobiles, vehicles, and other devices with vibrations, and prevents loosening. The present invention relates to a lock nut having a function.

2. Description of the Related Art Conventionally, fastening bolts and nuts used in many mechanical devices, vehicles, and the like may gradually loosen due to vibration generated from the mechanical device itself, or external force or vibration. Various means have been proposed as means for preventing such loosening of the nut as follows. For example, there are means using a spring washer or a toothed washer (not shown). The spring washer is a part of a flat washer that has elastic force, and the cut part is slightly bent in the opposite direction, causing a repulsive force that is always stretched between the nut and the fastened member, This prevents the nut from loosening.

Moreover, the following patent documents can be mentioned as a well-known technique relevant to this invention.

Japanese Patent Laid-Open No. 11-315820

The spring washer described above can be expected to have a locking effect immediately after being fastened. However, if the spring washer is used for a long period of time, the elastic force of the spring becomes weak and the locking effect may be reduced. A toothed washer can be expected to have a locking effect if it is a small machine or a material whose fastening is softer than metal. I can't expect much effect.

In addition, for double nuts that have a locking effect, it is necessary to tighten two nuts, a fastening nut and a locking nut, at one tightening location, which takes twice as much work time and tightens each nut. Torque management is also difficult.

The present invention is a lock nut that has been devised in view of the above problems. When the lock nut is fastened to a bolt or a stud bolt, the periphery of the screw hole at the upper end of the nut is proportional to the tightening torque of the nut. The threaded part is forcibly tightened, and the anti-loosening effect between the bolt and the nut is generated by the frictional resistance, and the lock ring is then fitted to maintain the anti-loosening effect for a long time.

The lock nut according to the present invention has a plurality of vertical slits radially from the central axis of the screw hole from the upper end portion to the lower end portion of the lock nut, and the seat surface of the lock nut has an outer peripheral dimension like a nut with a flange. Expand. In addition, the bottom surface of the lock nut is screwed with the screw shaft of the bolt so that the bearing surface of the lock nut is deformed by receiving a pressing force from the fastened member to the outer periphery of the bottom surface of the lock nut. The shape of an inverted mortar having a gap in the peripheral part of the shaft is formed. In order to prevent loosening after tightening the lock nut, a cylindrical protrusion and a lock ring support are provided at the upper end of the lock nut, and the lock ring is fitted therein. Further, a flange-like protrusion is provided on the flange around the lock ring support portion of the cylindrical protrusion so that the lock ring is not easily detached from the cylindrical protrusion of the lock nut.

With the above configuration, the lock nut of the present invention is fastened to the bolt, so that the bolt and the lock nut are closely fitted to each other by receiving a pressing force from the fastened member, and a nut that is strong against loosening is provided. Furthermore, it has a long-term locking prevention effect by fitting a lock ring into the upper end of the lock nut. Since the lock ring cannot be fitted unless the lock nut is completely tightened, it also serves as a function to prevent forgetting to tighten the lock nut.

Further, the lock nut of the present invention is easy to install, has good workability, has a small number of parts, and can be manufactured at a relatively low material cost.

It is an external appearance perspective view of the lock nut and lock ring which concern on the 1st Embodiment of this invention. It is the top view of the lock nut of FIG. 1, and a lock ring, and the sectional view on the AA line of the center part. (A) shows embodiment of the lock nut of FIG. 1, a lock ring, and a volt | bolt, BB sectional drawing of the center part of FIG. 2 just before a lock nut clamp | tightens and fixes to a bolt on both sides of a to-be-fastened material. It is. FIG. 3B is a cross-sectional view taken along the line B-B of FIG. 2 when the lock ring is fitted into the lock nut after the lock nut is further tightened with the specified torque from the state of FIG. It is the external appearance perspective view which showed the form of the basic specification without the lock ring of the lock nut of FIG. It is the external appearance perspective view which showed the state which gave the lock nut of FIG. It is the front view which showed the form for strengthening the frictional resistance which the screw hole of the lock nut of FIG. 1 exerts on the thread of a bolt. FIG. 3 is a cross-sectional view taken along the line B-B of the center portion based on the plan view of FIG. 2, showing measures for strengthening the locking nut of FIG. 1 and for strengthening the lock nut or the lock ring against external rocking force. It is the external appearance perspective view of the lock ring which showed the form of the specification with a cover which had the appearance improvement of the external appearance of the lock nut of FIG. 1, and the artificial tampering prevention function. It is the external appearance perspective view which showed the form which the lock ring of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

As shown in FIGS. 1 and 2, the lock nut 1 extends from the central axis of the screw hole 8 to a depth of about 60 to 80% of the height of the lock nut from the upper end portion of the lock nut toward the bottom surface of the lower end portion. A plurality of vertical slits 7 are provided radially. The location of the outer peripheral side surface where the vertical slit 7 enters is optimally at the approximate center of the nut tightening tool mounting surface 1a where the wrench (or spanner) contacts the lock nut, and the number of vertical slits is preferably two or more. Moreover, the seat surface of the lock nut 1 has a flange 2 larger than the outer diameter of the nut portion (the outer diameter of the nut tightening tool mounting portion 1a). The shape of the bottom surface 2c of the flange 2 is the inverse of the center point of the screw hole 8 slightly raised from the center of the bottom surface, with the virtual vertex being the outer peripheral portion 2b of the bottom surface of the lock nut 1 corresponding to the outer peripheral side of the conical shape. It has a mortar shape.

The angle 2d formed by the inverted mortar-shaped bottom surface 2c of the lock nut 1 and the surface of the member 6 to be fastened in FIG. 3 is such that when the lock nut 1 is completely tightened with a specified torque, the vicinity of the screw hole in the center of the bottom surface 2c is It is set so as to slightly contact the fastened member 6.

The depth and width of the vertical slit 7 to be inserted into the side surface of the lock nut 1 is such that when the lock nut 1 is tightened to the bolt 5 with a specified torque, the upper end of the lock nut is reduced in diameter toward the central axis of the screw hole 8 and locked. The screw hole of the top end of the nut and the screw thread of the bolt are in close contact with each other, and the lock nut is not broken or plastically deformed. ing.
Also, the bottom shape 2a of the vertical slit 7 of the lock nut 1 is slightly inclined from the horizontal toward the lower end of the central axis of the screw hole 8, and the lock nut 1 is tightened when the lock nut 1 is tightened. The cylindrical protrusion 4 and the nut tightening tool mounting portion 1a divided by a plurality of radial vertical slits 7 at the upper end portion are easily reduced in diameter toward the central axis of the screw hole 8, and the outer slit is formed. Forming it as shallow as possible is an element that increases the strength of the lock nut 1.

Furthermore, a cylindrical protrusion 4 for fitting and supporting the lock ring 3 is provided at the upper end of the lock nut 1 so that the lock ring 3 is not detached from the lock ring support 4 a and the lock nut 1. It is comprised by the collar-shaped protrusion 4b on the collar of the outer periphery of the part 4a. The height of the protrusion 4b is set to a minimum size so that the lock ring 3 is not hindered and cannot be easily detached when the lock ring 3 is fitted into the lock ring support 4a using a wrench and a hammer. The inner diameter S of the lock ring 3 is smaller than the outer diameter P of the lock ring support portion 4a, and when the bolt 5 shown in FIG. In addition, there is no gap between the inner surface 3a of the lock ring 3 and the outer surface of the lock ring support portion 4a, and the lock ring 3 is set so as to be in close contact (preferably in a state where it is pressed to some extent). Further, the thickness of the lock ring 3 is formed in accordance with the height of the lock ring support portion 4a, and the outer diameter of the lock ring 3 is set to be slightly larger than the outer diameter of the nut portion 1a. When removing from the lock nut 1, the spanner can be removed by inserting it into the nut portion 1 a of the lock nut 1 and pulling it up.

FIG. 3A shows an initial state in which the lock nut 1, the lock ring 3 and the bolt 5 are fastened to the fastened member 6. When the lock nut 1 is fastened with the fastened member 6 sandwiched between the bolts 5, The outer peripheral portion 2 b of the bottom surface of the lock nut contacts the fastened member 6.

When the lock nut 1 is further tightened, the pressure in the lower end direction applied from the thread 9 of the bolt 5 to the screw hole 8 of the lock nut 1 pushes down the bottom surface 2c near the screw hole, and the lock nut 1 A lateral stress in which the cylindrical protrusion 4 at the upper end of the lock nut 1 is reduced in diameter toward the central axis of the screw hole 8 by the pressing force acting on the outer peripheral portion 2b of the bottom surface. Work. Then, the face of the screw hole valley 8a at the upper end of the lock nut 1 and the face of the screw thread 9a of the bolt 5 are closely fitted to each other, and a large frictional resistance is generated at that portion, whereby the bolt 5 and the lock nut 1 are Together, a nut that is strong against loosening is formed.

Next, as shown in FIG. 3B, when the lock ring 3 is inserted into the lock ring support 4a at the upper end of the lock nut 1, the screw hole 8 at the upper end of the lock nut 1 and the thread 9 of the bolt 5 are pressed. Since the comrades are fixed and mechanically stable, and the cylindrical protrusion 4 does not expand to the original shape even from external vibrations, a nut that does not loosen for a long time can be provided.

FIG. 4 shows a basic type of the lock nut 1 that does not have the lock ring 3 attached thereto. It is ideal for use in places such as buildings where it is not subject to external vibrations, and when painting is applied after the lock nut is installed and tightened. After the lock nut 10 is tightened to the bolt 5, the paint is applied to the surface of the lock nut 10 as shown in FIG. 5, so that the paint enters each slit 7, and the paint 10a serves as a screw lock (adhesive). It can be expected to prevent loosening by bonding between the bolt and bolt.

FIG. 6 shows a method of further strengthening a lateral stress in which the upper end portion of the lock nut 1 of FIG. 1 is reduced in diameter toward the central axis direction of the screw hole 8, and each bottom portion 2 e of the seating surface of the flange 2 of the lock nut 11. Is formed in a mountain shape. It is preferable to set the location that is the apex of each mountain shape to the substantially outer peripheral portion between the adjacent vertical slits 7, and the height of the mountain is completed by tightening the lock nut 11 to the bolt 5 with the specified torque. It is desirable to set so that the bottom 2f of the flange 2 directly below each slit 7 is slightly lifted from the fastened member 6 at the time. The pressing force received by each mountain-shaped apex portion 2e from the fastened member 6 is the maximum stress that acts on the cylindrical protrusion 4 at the upper end of the lock nut 11 in the central axis direction of the screw hole. This method can also be applied to the lock nut 10 of FIG.

FIG. 7 shows a method 1 for strengthening the locking effect of the lock nut 1 and the bolt 5 of FIG. 1 as a concentric groove 2h centering on the central axis of the screw hole 8 on the bottom surface of the lock nut 12 (for example, FIG. In the longitudinal sectional view, a plurality of semicircular grooves) are formed. By forming the groove 2h, it is formed on the bottom surface of the lock nut 12 against the static frictional force generated on the surface of the screw hole 8 at the upper end of the lock nut 12 and the surface of the thread 9 of the bolt 5. The static frictional force generated on the surface of the concentric projection 2i and the surface of the member 6 to be fastened is small, and the static friction generated relatively on the surface of the screw hole 8 of the lock nut 12 and the screw thread 9 of the bolt 5. Since the frictional force increases and the binding force increases, it is possible to enhance the prevention of the lock nut from loosening against external vibration. This method can also be applied to the lock nut 10 of FIG.

Further, as a method 2 for enhancing the locking effect of the lock nut 1 and the bolt 5 of FIG. 1, the inner surface 3b of the lock ring 30 of FIG. 7 or the surface of the lock ring support 4c of the lock nut 12 is applied to the surface of FIG. By providing a saw-shaped shape or a shape that increases the friction coefficient such as irregularities as shown in the longitudinal sectional view, it acts as a cushioning material on the opposing contact surface, improving the closeness of the lock nut 12 and the lock ring 30 and external rocking force Anti-loosening effect can be expected.

FIG. 8 shows another specification of the lock ring 3, which is a lock ring 31 with a cover with a side cover 31 a that clearly shows the appearance of the lock nut 1. The height of the side cover 31 a is such that when the lock ring 31 with cover is fitted into the lock ring support 4 a at the upper end of the lock nut 1, the bottom surface 31 b below the side cover 31 a is slightly on the surface of the flange 2 of the lock nut 1. A length and a shape in contact with are preferable. Further, the inner diameter of the side cover 31a is slightly larger than the outer diameter of the nut portion 1a of the lock nut 1, and the thickness of the side cover 31a is appropriately set so as not to be easily deformed by an external force or impact. It also functions to prevent mischief such as removing nuts.

FIG. 9 is a developed version of the lock ring 3, and the outer dimensions and the like are substantially the same as those of the lock ring 3, but the lock ring 32 is of a specification that can be repeatedly inserted and removed any number of times. The material is made of an elastic metal or the like, is rolled in a horizontal direction and wound in a spiral shape, and the inner diameter of the lock ring 32 is the same as that of the lock ring 3. By setting it smaller than the diameter and making it spiral, tension always acts in the direction of the central axis of the lock ring, and when the lock ring 32 is detached from the lock nut 1, the original shape can be obtained even if the diameter of the lock ring slightly increases. By returning to, the initial characteristics and shape can be maintained, and the specification can be repeatedly inserted and removed.

1, 10, 11, 12 Lock nut 1a Nut part or nut tightening tool mounting part 2 Flange 2a Bottom of slit 2b Outer peripheral part of bottom face of lock nut 2c Bottom face of lock nut 2d Inclination angle of bottom face of lock nut 2e Between slits The bottom part of the outer peripheral part of the seating surface which becomes the center position 2f The bottom part of the seating face which becomes the position immediately below the slit 2h The concentric groove part on the bottom surface of the lock nut 2i The concentric protrusions on the bottom surface of the lock nut 3, 30, 31, 32 Lock Rings 3a, 3b Inner surface of the lock ring 31a Side cover portion of the lock ring 31b Bottom surface of the side cover of the lock ring 4 Cylindrical protrusions 4a, 4c Lock ring support portion of the cylindrical protrusion 4b Collar shape of the lock ring support portion 5 Bolt 6 Fastened member 7 Slit 8 Screw hole 8a Screw hole surface (flank)
9 Bolt thread section 9a Bolt thread face (flank)

Claims (5)

A lock nut having a screw hole to be screwed with a screw shaft of a bolt, and having a plurality of vertical slits on the side surface of the lock nut from the upper end to the lower end of the lock nut , and the location of the side where the vertical slit enters Is a central portion of the nut tightening tool mounting surface, the seat surface of the lock nut is provided with a flange larger than the outer diameter of the lock nut, and the center point of the screw hole is virtually on the periphery of the center axis of the bottom surface of the lock nut . It has an inverted mortar-shaped gap that becomes the apex , a cylindrical protrusion is formed at the upper end of the central axis of the screw hole of the lock nut, and a flange-like protrusion is provided on the outer periphery of the cylindrical protrusion. , a lock ring of a cylindrical shape that fits to the outside of the cylindrical projection, the inner diameter of the locking ring is smaller than the outer diameter of the cylindrical projection, the inner diameter of the lock ring, said cylindrical projection When the lock nut is completely tightened to the bolt so that the lock ring can be inserted into the bolt, the cylindrical protrusion is contracted to the center of the screw hole by the pressing force applied to the outer periphery of the flange from the fastening surface. The outer diameter of the cylindrical projecting portion is the smallest dimension, and the lock ring is inserted after the above tightening, and the upper portion of the lock nut divided by the slit is fixed so as not to move. Lock nut characterized by that.     The lock nut according to claim 1, wherein the bottom surface of the lock nut is formed at the center of adjacent vertical slits and the outer peripheral portion of the bottom surface of the lock nut is a mountain-shaped apex, and the bottom surface is made as high as the number of slits. A lock nut characterized by being formed.     The lock nut according to claim 1, wherein a plurality of concentric grooves centering on a central axis of the screw hole are formed on a bottom surface of the lock nut. 2. The lock nut according to claim 1 , wherein a cross-section is formed in a saw-shaped or irregular shape with a high friction coefficient on one surface of a lock ring support portion of the lock nut or an inner surface of the lock ring. lock nut or lock ring and said that it has. The lock ring used for the lock nut according to claim 1 , wherein an inner diameter of the lower end portion of the lock ring is larger than a nut outer diameter of the lock nut, an outer diameter is adjusted to an outer diameter of the lock ring, and a height is set to the height. A lock ring comprising a cylindrical side cover set to a height up to an upper surface of a flange of the lock nut when the lock ring is mounted on the lock nut.

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