JP3182047U - Bolt and nut locking structure - Google Patents

Abstract

Provided is a bolt and nut loosening prevention structure in which a nut can be securely removed by caulking while a nut can be easily removed from the bolt as needed.
A cylindrical central hole 1c extending in the axial direction is formed at the tip of a screw shaft 1b of a bolt 1, and is thin with a predetermined length so that it can be deformed upward at one axial end of a nut 2. The cylindrical screw hole portion 2c is integrally formed to project, and after the nut 2 is screwed onto the bolt 1, the tip-shaped hammer body 3 of the diameter expanding tool is press-fitted into the central hole portion 1c of the bolt 1 from the axial direction. Then, the central hole 1c of the bolt 1 and the cylindrical screw hole 2c of the nut 2 are expanded together in a trumpet shape to prevent loosening.
[Selection] Figure 1

Description

  The present invention relates to a bolt and a nut loosening prevention structure in which a nut or a bolt is caulked and then loosened after the nut is screwed onto the bolt.

  Conventionally, as a bolt and nut loosening prevention structure by caulking, one bolt is formed with a slit extending in the axial direction at a part of the outer periphery of the shaft end, and the other nut is a thin wall that can be crushed and deformed into the slit Is known in which the cylindrical projecting edge portions are integrally formed concentrically.

  After the nut is screwed onto the bolt, the cylindrical protruding edge of the nut is crushed and deformed into the slit of the bolt to prevent the nut from loosening.

  Japanese Utility Model Publication No. 51-99251

  By the way, according to the bolt and nut loosening prevention structure described above, the cylindrical protruding edge portion of the nut is crushed and deformed into the slit extending in the axial direction on the outer periphery of the bolt. However, when it becomes necessary to remove the nut from the bolt for maintenance or the like, there is a problem that it becomes difficult to easily remove the nut from the bolt.

  Therefore, according to the present invention, the nut can be easily and reliably prevented from loosening with respect to the bolt. In addition, the nut can be removed from the bolt even when it is necessary to remove the nut from the bolt due to maintenance or the like. It is an object of the present invention to provide a bolt and nut locking structure that can be used.

  In order to solve the above-mentioned problem, the device according to claim 1 of the present application is composed of a bolt and a nut screwed into the bolt, and one bolt has a cylindrical central hole portion extending in the axial direction at the tip end portion of the screw shaft. The other nut is formed with a thin cylindrical screw hole with a predetermined length so that it can be deformed upward at one end in the axial direction, and the nut is screwed onto the bolt. After that, a tapered tapered hammer body in the diameter expansion tool is pressed into the center hole of the bolt from the axial direction, and the center hole of the bolt and the cylindrical screw hole of the nut are expanded and deformed into a trumpet shape together. It is characterized by being configured to prevent loosening.

  According to a second aspect of the present invention, in the configuration of the first aspect, the nut is provided with a dish-shaped flange at the other axial end, and the inner diameter portion is flanged on the seat surface side of the flange. A notch is formed to give elasticity to the flange, and when a soft member to be fastened such as aluminum is fastened, the flange is bent to prevent the flange from being depressed into the seating surface, and at the same time elastically restored. It is characterized by having a function of preventing looseness in a non-rotating state by force.

  The invention described in claim 3 of the present invention is based on the idea described in claim 1, wherein an air hammer is used as the diameter expanding tool, and a central hole portion of the bolt and a cylindrical screw hole portion of the nut are formed by pushing the hammer body having a tapered tip. While the diameter of the hammer is gradually expanded, a restricting body that abuts the bottom surface of the central hole of the bolt and restricts the amount of pushing is provided at the tip of the hammer so that the protruding length can be adjusted. By adjusting the projecting length of the body, the central hole portion of the bolt and the cylindrical screw hole portion of the nut are enlarged and deformed into a trumpet shape at a predetermined angle.

  The invention according to claim 4 of the present invention is the invention according to claim 3, wherein one or a plurality of protrusions are formed on the tapered outer periphery of the hammer body, and the hammer body having the protrusions is press-fitted. Thus, the central hole portion of the bolt and the cylindrical screw hole portion of the nut are enlarged and deformed into a trumpet shape at a predetermined angle, and the protrusions are partially engaged with each other.

  According to the bolt and nut loosening prevention structure of the present invention, after tightening the nut to the bolt with the above-described configuration, the tip-shaped hammer body of the diameter expanding tool is press-fitted from the axial direction into the central hole of the bolt. By loosening and deforming the central hole portion of the bolt and the thin cylindrical screw hole portion of the nut into a trumpet shape together, it is possible to reliably prevent both of them from loosening.

  In addition, if a notch for giving elasticity to the flange is formed in the inner diameter portion on the bearing surface side of the flange in the nut, the flange is bent when a soft fastened member such as an aluminum material is fastened. This is preferable because it can prevent the member to be fastened from being depressed into the seating surface, and at the same time, can exhibit a non-rotating state locking function by elastic restoring force.

  In addition, an air hammer is used as a diameter expanding tool, and a regulating body that abuts the bottom surface of the central hole of the bolt and regulates the amount of pushing is provided at the tip of the hammer body so that the projecting length can be adjusted. By adjusting the projecting length of the restricting body so that the center hole of the bolt and the cylindrical screw hole of the nut can be enlarged and deformed in a trumpet shape at the required angle, the crimping can always be stopped with a predetermined force. A reliable anti-loosening effect can be obtained. In addition, since the caulking force can be set, when it becomes necessary to remove the nut from the bolt due to maintenance, etc., the nut is rotated in the loosening direction against the caulking force, and the portion whose diameter has been enlarged and deformed into the trumpet shape is restored. It is also possible to remove the nut from the bolt by pushing back to the state.

  Furthermore, if, for example, two engaging protrusions are formed on the tapered outer peripheral portion of the hammer body, the central hole portion of the bolt and the cylindrical screw hole portion of the nut are expanded and deformed into a trumpet shape at a predetermined angle. At the same time, the center hole portion and the cylindrical screw hole portion are engaged with each other at two locations by the engaging projection, and as a result, a synergistic effect of the trumpet-shaped diameter expansion deformation and the projection engagement. In addition, the effect of preventing loosening in both can be exhibited more firmly.

It is a partially notched front view which shows the coupling | bonding state of the volt | bolt and nut provided with this invention structure. It is a partially cutaway front view before use of the bolt and nut. It is a front view in the state where a nut was temporarily screwed onto the bolt. It is a partially vertical side view which shows the shape of another hammer body. It is a transverse end view of the caulking part by the hammer body.

  Embodiments of the bolt and nut locking structure according to the present invention will be described below with reference to the drawings.

  1 and 2, reference numeral 1 denotes a bolt composed of a head 1a and a screw shaft 1b. A cylindrical central hole 1c extending in the axial direction is formed at the tip of the screw shaft 1b.

  A nut 2 is screwed to the bolt 1 and has a flange 2b at one end in the axial direction of the hexagon nut body 2a, and a thin cylindrical screw hole with a predetermined length so that it can be deformed upward at the other end in the axial direction. The part 2c is integrally formed to project. Further, the flange 2b is dish-shaped, and a notch 2d for giving elasticity to the flange 2b at the time of fastening is formed in the inner diameter portion on the seat surface side. As a result, for example, when the soft fastened member 4 such as an aluminum material is fastened, the flange 2b is bent to prevent the flange 2b from sinking into the seating surface of the fastened member A, and at the same time non-rotation due to the elastic restoring force of the flange 2b. A state locking function is provided.

  Reference numeral 3 denotes a hammer body having a tapered tip attached to the tip of the air gun. By pushing the hammer body 3 into the central hole 1c of the bolt 1, the central hole 1c of the bolt 1 and the cylindrical screw hole 2c of the nut 2 are expanded in diameter stepwise, while the tip of the hammer body 3 is deformed. As shown in FIG. 2, a regulating body 4 that abuts against the bottom surface of the central hole 1c of the bolt 1 and regulates the pushing amount of the hammer body 3 is provided so as to be adjustable in projecting length. That is, the restricting body 4 can be adjusted for the amount of protrusion or exchanged with a different thickness in accordance with the length of the bolt 1 or the depth of the central hole 1c. By adjusting the protrusion length t of the body 4, the diameter of the central hole 1 c of the bolt 1 and the thin cylindrical screw hole 2 c are expanded and deformed into a trumpet shape at a predetermined angle θ. The overall configuration of the air hammer is composed of a compressor, an air gun connected to the compressor, and a hammer body 3 shown in FIG. 2 attached to the tip of the air gun. Since the structure of the hammer is already known, its structure and operation will be omitted.

  Next, the operation of the bolt and nut provided with the loosening prevention structure of the present invention will be described.

  First, as shown in FIG. 3, the nut 2 is screwed onto the screw shaft 1b of the bolt 1 passing through the fastened member A, and tightened until the flange 2b of the nut 2 is bent and becomes flat as shown in FIG. To do. Next, using an air hammer, the tapered hammer body 3 is pressed into the center hole 1c of the bolt 1 stepwise from the axial direction while driving in small increments using air pressure. As a result, as shown in FIG. 1, the central hole portion 1c of the bolt 1 and the cylindrical screw hole portion 2c of the nut 2 are expanded and deformed together in a trumpet shape, thereby preventing the loosening of both.

  At this time, since the notch 2d for giving elasticity to the flange 2b is formed on the inner diameter portion of the nut 2 on the bearing surface side of the flange 2b, the flange 2 is fastened when the fastened member A such as soft aluminum is fastened. 2b can be bent to prevent the flange 2b from sinking into the seating surface of the fastened member A, and at the same time, a non-rotating state locking function by elastic restoring force can be exhibited.

  Further, at the tip of the tapered hammer body 3, a regulating body 4 that abuts against the bottom surface of the central hole portion 1c of the bolt 1 and regulates the amount of pushing is projected so as to be adjustable in projecting length. 4 is configured such that the central hole portion 1c of the bolt 1 and the cylindrical screw hole portion 2c of the nut 2 can always be expanded in a trumpet shape at a predetermined angle θ by adjusting the projecting length of 4. Can be caulked and provides a reliable anti-loosening effect without variation. In addition, since it can be set to the required caulking force, even when it is necessary to remove the nut from the bolt due to maintenance or the like, the nut 2 is rotated in the loosening direction against the caulking force, and the diameter is expanded and deformed into the trumpet shape. It is also possible to remove the nut 2 from the bolt 1 by pushing the part back to the original state.

  FIGS. 4 and 5 show a hammer body 3 of an air hammer that is used for particularly firmly preventing loosening. Two engagement protrusions 3a, 3a is formed. When the hammer body 3 having the engagement protrusions 3a and 3a is press-fitted into the central hole 1c of the bolt 1 in a fastened state, the central hole 1c of the bolt 1 and the cylindrical screw portion 2c of the nut 2 have a predetermined angle. At the same time, the diameter is enlarged and deformed into a trumpet shape by θ, and at the same time, as shown in FIG. 5, two portions bulged by the engaging protrusions 3a, 3a are engaged with the protrusions. As a result, due to the synergistic effect of the trumpet-shaped diameter expansion deformation and the protrusion engagement, the loosening prevention effect of both can be exerted more firmly. In addition, two engaging protrusions 3a may be provided, or may be one or two or more.

  Further, in the above-described embodiment, the air hammer is used as the diameter expanding tool so that the loosening prevention work can be performed quickly and easily. However, instead of the air hammer, for example, a hand-held hammer is used, and the diameter is expanded and deformed by hand. You may do it.

1 Bolt 1b Screw shaft 1c Center hole 2 Nut 2a Nut body 2b Flange 2c Cylindrical screw hole 3 Tapered hammer body 3a Engaging protrusion

Claims (4)

  It consists of a bolt and a nut that engages with it. One bolt has a cylindrical central hole extending in the axial direction at the tip of the screw shaft, and the other nut faces upward at one end in the axial direction. A thin cylindrical screw hole with a predetermined length is formed so as to be deformable, and after the nut is screwed onto the bolt, the tip of the diameter expanding tool is tapered at the center hole of the bolt. A bolt characterized in that it is configured to prevent loosening by press-fitting a hammer body from the axial direction, and expanding and deforming the central hole portion of the bolt and the cylindrical screw hole portion of the nut into a trumpet shape together; Nut locking structure.   The nut is provided with a dish-shaped flange at the other end in the axial direction, and a notch is formed on the inner surface of the flange on the bearing surface side to make the flange elastic. 2. The non-rotating state locking function by elastic restoring force is provided at the same time that the flange is bent when the member is fastened to prevent the flange from sinking into the seating surface. Bolt and nut locking prevention structure.   An air hammer is used as a tool for expanding the diameter, and the center hole of the bolt and the cylindrical screw hole of the nut are gradually expanded by pressing a hammer body with a tapered tip. A regulating body that abuts the bottom surface of the central hole portion of the bolt and regulates the amount of pushing is projected so that the projecting length can be adjusted, and by adjusting the projecting length of the regulating body, the central hole portion of the bolt and the nut 2. The bolt and nut loosening prevention structure according to claim 1, wherein the cylindrical screw hole is enlarged and deformed in a trumpet shape at a predetermined angle.   One or a plurality of protrusions are formed on the tapered outer peripheral portion of the hammer body, and the central hole portion of the bolt and the cylindrical screw hole portion of the nut are wrapped at a predetermined angle by press-fitting the hammer body having the protrusion portion. 4. The bolt and nut loosening prevention structure according to claim 3, wherein the structure is expanded and deformed into a shape and is partially engaged with a protrusion.

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