JP2013096504A - Locking structure of screw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a locking structure of a screw which can perform the locking of the screw as it is by the fastening operation of the screw.SOLUTION: The locking structure of the screw is constituted so that a hole 5 is formed along the axis center of the front end side of a shaft 3 in which a male screw 4 is formed, and a protrusion 6 is attached to the hole 5. When clamped parts 10, 20 are clamped by the screw-connection of the male screw 4 and a female screw 12, the protrusion 6 contacts with the bottom face of a recessed portion 11 in which the female screw 12 is formed by the entering of the protrusion 6 into the hole 5, the front end side of the shaft 3 in which the male screw 4 is formed is spread.

Description

  The present invention relates to a screw loosening prevention structure that prevents a screw from loosening due to vibration or the like in a fastener that uses a male screw and a female screw such as a bolt and a nut.

  For example, when a plate-like component is coupled to the end face of a columnar body such as a boss, a female screw hole is formed in the end surface of the columnar body, and a hole is formed in the plate-shaped component to be coupled. The plate-like component is fastened to the columnar body by inserting a bolt into the hole and screwing the tip portion into the female screw hole of the columnar body.

  If vibration is applied to components joined using such screws over a long period of time, the screws may loosen and the components may come off. In order to prevent this, various screw locking structures have been proposed.

  For example, in Patent Document 1, a bolt is formed in a hollow shape to hold a lock pin in the hollow portion, a split groove is formed in a tip portion of the bolt, a nut is screwed into the bolt, A technique for preventing loosening of the screw by expanding the tip of the bolt by driving a pin and breaking the engagement between the screw threads of the bolt and nut is disclosed.

  Further, in Patent Document 2, an unevenness is formed on the outer peripheral surface of the front end portion of the bolt, and after the bolt and the nut are screwed together, the outer peripheral portion of the unevenness in the nut is compressed and deformed by a hydraulic press or a die, A technique for preventing loosening of a screw by causing a part of a nut to bite into an irregularity so that the bolt does not rotate alone is disclosed.

Japanese Utility Model Publication No. 6-12819 Japanese Patent Laid-Open No. 7-28661

  However, in the above-described techniques, in order to prevent the screws from being loosened, it is necessary to perform another operation after tightening the screws, which is troublesome. Further, in order to prevent the screws from loosening, a tool, a hammer, a press machine, or the like, which is a different type of tool from the tightening of the screws, is required, and the work is complicated.

  The present invention has been made in view of the above-described problems of the background art, and an object of the present invention is to provide a screw loosening prevention structure that can prevent a screw from being loosened by a screw tightening operation.

In order to achieve the above-described object, the present invention has a screw locking structure described below.
[1] A hole or a split groove is formed along the shaft core on the distal end side of the shaft portion on which the male screw is formed, and a projection is attached to the hole or the split groove, and the male screw and the female screw are screwed together. When the object to be fastened is fastened, the projection comes into contact with the bottom surface of the concave portion in which the female screw is formed, and the projection bites into the hole or the split groove, so that the distal end side of the shaft portion of the male screw is expanded. A structure for preventing screw loosening.
[2] The screw loosening prevention structure according to [1], wherein an enlarged space portion having a diameter larger than that of the female screw is formed at the bottom of the concave portion in which the female screw is formed.
[3] The protrusion mounted in the hole or the split groove has a truncated cone shape, and is mounted with the narrower side inserted into the hole or the split groove. [1] or [2] Screw locking structure as described in 1.
[4] The screw loosening prevention structure according to any one of [1] to [3], wherein the protrusion mounted in the hole or the split groove is attached by an adhesive.

According to the above-described screw loosening prevention structure according to the present invention, the screw loosening prevention is performed only by a rotation operation indispensable for screw fastening. That is, with the rotation operation for tightening the screw, the protrusion bites into the hole or the split groove formed at the tip of the bolt, and the tip of the bolt is expanded to prevent the screw from loosening. For this reason, no operation other than the operation of rotating the screw is required, and no separate tool is required, so that the screw loosening prevention operation can be performed easily and quickly.
Moreover, the screw locking structure according to the present invention is realized by adding a process of forming a hole or a split groove at the tip of the shaft portion on which the male screw is formed, and a process of attaching a projection to the hole or the split groove. Since these processes can be easily performed even with a small screw, it is particularly effective as a structure for preventing the loosening of the screw.

It is the side view which made a part of bolt the cross section shown as an example which realizes the screw locking structure concerning the present invention, and (a) shows the state where the projection was separated, and (b) shows the state where the projection was attached. FIG. It is the side view which made the cross section the part which showed one Embodiment which implement | achieved the screw locking structure which concerns on this invention using the volt | bolt shown in FIG. 1, Comprising: (a) is before the fastening of a member A state and (b) are the figures which respectively showed the state after the fastening of a member. It is the figure which expanded and showed the A section of FIG.2 (b). It is the side view which made the cross section the part which showed other embodiment which implement | achieved the screw locking structure which concerns on this invention using the volt | bolt shown in FIG. 1, Comprising: (a) is before fastening of a member (B) is the figure which each showed the state after the fastening of a member. It is the figure which expanded and showed the B section of FIG.4 (b).

  Hereinafter, a screw locking structure according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a view of a bolt shown as an example for realizing a screw locking structure according to the present invention. The bolt 1 includes a head portion 2 and a shaft portion 3, and the head portion 2 has a hexagonal column shape. This is a so-called hexagon bolt in which a male screw 4 is formed on the peripheral surface of the shaft portion 3. A hole 5 is formed along the axial center on the tip side of the shaft portion 3 of the bolt 1, and a truncated cone-shaped protrusion 6 is attached to the hole 5 with an adhesive.

  The hole 5 is formed so that the distal end portion of the shaft portion 3 is easily expanded and deformed, and its diameter and depth are designed so that it can be expanded and deformed by a method described later. . Further, when the object to be fastened is fastened by screwing the male screw 4 of the bolt 1 and a female screw (not shown), the protrusion 6 abuts on the bottom surface of the recess in which the female screw is formed, and bites into the hole 5. Accordingly, the mounting position, length, and inclination angle are designed so that the tip of the shaft portion 3 is expanded and deformed.

  FIG. 2 shows an embodiment in which the bolt 1 configured as described above is used to realize the screw locking structure according to the present invention. The screw locking structure shown in FIG. 2 includes a columnar body 10 of a component that is a base material, a plate-like body 20 that is another component coupled to the tip surface 10a of the columnar body 10, and a combination thereof. It consists of the bolt 1 described above.

  The columnar body 10 is formed with a recess 11 at the center of the front end surface 10a, and a female screw 12 is formed on the peripheral surface of the recess 11 to be screwed with the male screw 4 of the bolt 1. An enlarged space portion 13 having a diameter larger than that of the screw 12 is formed. On the other hand, a hole 21 is formed in the plate-like body 20.

  In this screw locking prevention structure, as shown in FIG. 2, the hole 21 is matched with the recess 11 of the columnar body 10 and the plate-like body 20 is overlapped, and the shaft portion 3 of the bolt 1 is inserted into the hole 21. At the same time, the male screw 4 of the bolt 1 is screwed with the female screw 12 of the recess 11. Then, by rotating the bolt 1 in the tightening direction, the columnar body 10 and the plate-shaped body 20 are fastened and the screws are prevented from loosening.

  That is, when the bolt 1 is rotated in the tightening direction, the front end of the shaft portion 3 of the bolt gradually approaches the bottom portion of the recess 11 due to the screwing of the male screw 4 and the female screw 12, and the protrusion attached to the front end of the shaft portion 3. 6 contacts the bottom of the recess 11. Further, by further rotating from this state, the columnar body 10 and the plate-like body 20 are fastened, and as shown in FIG. 3, the protrusion 6 bites into the hole 5, thereby leading the tip of the shaft portion 3. The portion is expanded, the male screw 4 and the female screw 12 are pressed against each other, and the expanded shaft portion 3a enters into the enlarged space portion 13 of the concave portion 11, thereby preventing a strong screw from loosening.

  FIG. 4 is a view showing another embodiment in which the above-described bolt 1 is used to realize the screw locking structure according to the present invention. The screw locking structure shown in FIG. 4 is composed of two plate-like bodies 30 and 30, the above-described bolt 1 that connects them, washers 40 and 40, and a nut 50.

  In the two plate-like bodies 30 and 30, holes 31 and 31 are formed, respectively. The nut 50 is a nut having a bottom plate 50 a, and a female screw 52 that is screwed with the male screw 4 of the bolt 1 is formed on the peripheral surface of the recess 51, and the bottom portion has a larger diameter than the female screw 52. A space 53 is formed.

  In this screw locking structure, as shown in FIG. 4, the holes 31, 31 of the two plate-like bodies 30, 30 are aligned and overlapped, and washers 40, 40 are arranged above and below them. The shaft portion 3 of the bolt 1 is inserted through them, and the male screw 4 of the bolt 1 is screwed with the female screw 52 of the nut 50. Then, by rotating the bolt 1 or the nut 50 in the tightening direction, the two plate-like bodies 30 and 30 are fastened and the screws are prevented from loosening.

  That is, when the bolt 1 or the nut 50 is rotated in the tightening direction, the tip of the shaft portion 3 of the bolt gradually approaches the bottom plate 50a of the nut 50 due to the screwing of the male screw 4 and the female screw 52. The protrusion 6 attached to the abutment comes into contact with the bottom plate 50 a of the nut 50. Further, by further rotating from this state, the two plate-like bodies 30 and 30 are fastened, and as shown in FIG. 5, the protrusion 6 bites into the hole 5, whereby the tip of the shaft portion 3. The portion is expanded, the male screw 4 and the female screw 52 are pressed against each other, and the expanded shaft portion 3a enters into the enlarged space portion 53 of the nut 50, so that a strong screw is prevented from loosening.

  The embodiment of the screw locking structure according to the present invention has been described above, but the present invention is not limited to the embodiment described above, and within the scope of the technical idea of the present invention, Naturally, various modifications and changes are possible.

  For example, in the above embodiment, the hole 5 is formed at the tip of the shaft portion 3, but it may be a slit (slit) instead of the hole 5, and both the hole and the split groove are formed. May be. Further, the mounting of the protrusions 6 may be not only an adhesive but also spot welding, partial crimping, simple fitting, and the like.

  Further, although the hexagon bolt 1 is shown as a member in which a male screw is formed, a so-called small screw in which a cross groove or a minus groove is formed in the head, a set screw having no head, or the like may be used. Furthermore, the shape of the protrusion 6 is not limited to the truncated cone shape, and may be any shape that can expand the hole or the split groove.

  The screw locking structure according to the present invention can be widely used in fasteners that use male and female screws such as bolts and nuts.

DESCRIPTION OF SYMBOLS 1 Bolt 2 Head 3 Shaft part 3a Expanded shaft part 4 Male screw 5 Hole 6 Protrusion 10 Columnar body 10a The front end surface of a columnar body 11 Recessed part 12 Female screw 13 Expansion space part 20 Plate-shaped body 21 Hole 30 Plate-shaped body 31 hole 40 washer 50 nut 50a bottom plate of nut 51 recess 52 female screw 53 enlarged space

Claims (4)

  A hole or split groove is formed along the shaft core on the tip side of the shaft portion on which the male screw is formed, and a projection is attached to the hole or split groove, and is fastened by screwing the male screw and the female screw. When an object is fastened, the protrusion comes into contact with the bottom surface of the recess in which the female screw is formed, and the protrusion penetrates into the hole or the split groove, thereby expanding the front end side of the shaft portion of the male screw. And a screw locking structure.   2. The screw locking structure according to claim 1, wherein an enlarged space portion having a diameter larger than that of the female screw is formed at a bottom portion of the concave portion in which the female screw is formed.   3. The screw according to claim 1, wherein the protrusion mounted in the hole or the split groove has a truncated cone shape and is mounted in a state where the narrower side is inserted into the hole or the split groove. Locking structure.   4. The screw loosening prevention structure according to any one of claims 1 to 3, wherein the projections attached to the holes or the split grooves are attached by an adhesive.

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