JP3128915U - Nut looseness prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a loosening prevention tool for reliably preventing a nut from loosening even when continuously receiving vibrations or shocks.
The present invention relates to a nut loosening prevention tool used to fasten and fasten a member to be fastened with a bolt and a nut, screwed into a male threaded portion of the bolt, and mounted in contact with an upper surface of the nut. A coil spring is provided; the coil spring is elastically deformed to be formed with an inner diameter that can be locked in the thread groove while expanding in the radial direction; and the ring material inserted from the axial direction of the bolt is a ring The inner surface of the material is attached so as to be in contact with the outer periphery of the coil spring, and the ring material is formed in a cylindrical shape having different diameters on the upper surface and the lower surface and having an inclined outer surface.
[Selection] Figure 6

Description

  The present invention relates to a loosening prevention device for a nut screwed to a bolt.

  For assembly of structures, tightening methods using bolts and nuts are generally used, and conventionally, various methods have been proposed as means for preventing the nuts from loosening.

  For example, the nut loosening that prevents the nut from loosening by screwing an annular nut loosening prevention tool formed of a coil spring or other wire in a spiral shape into the male thread of the bolt and restricting the nut from rotating in the return direction Preventive tools have been proposed (for example, Patent Documents 1 and 2).

  A nut loosening prevention tool including an inner coil spring that fits into a screw groove of a bolt and an outer coil spring that engages a nut mounted on the bolt has also been proposed (for example, Patent Document 3).

  Furthermore, a nut loosening prevention tool is also proposed in which a coil spring is mounted so as to fit into a screw groove of a bolt and covered with a cap so as to be in contact with the outer periphery of the coil spring. The cap that covers the outer periphery of the coil spring is formed in a cylindrical shape, and one that is mounted from the axial direction of the bolt or one that is mounted from the side surface of the coil spring has been proposed (for example, Patent Document 4).

JP 47-29743 A Japanese Patent Laid-Open No. 9-144739 International Publication No. 2003/095850 Pamphlet JP 2001-59514 A

  However, in the method of preventing the nut from loosening by screwing an annular nut loosening prevention tool formed of a coil spring or other wire in a spiral shape into the male threaded portion of the bolt and restricting the nut from rotating in the return direction Because it only regulates the rotation of the nut in the return direction, and there is no significant difference between the inclination angle of the coil spring strand and the inclination angle of the thread, it was continuously subjected to vibration and impact In this case, there is a problem that the coil spring is loosened and the nut is loosened accordingly.

  In addition, when using a nut loosening prevention tool including an inner coil spring that fits into a screw groove of a bolt and an outer coil spring that engages with a nut attached to the bolt, the shape of the coil spring becomes complicated, which makes it difficult to manufacture the coil spring. There was a problem of labor and cost.

  Furthermore, in the method of mounting the cap formed in a cylindrical shape so as to contact the outer periphery of the coil spring, the cap upper surface and the lower surface have the same cylindrical shape, so that the outer surface of the cap can be easily gripped with a tool such as a pipe wrench. The cap could be removed by applying a strong force.

  In order to advantageously solve the above-described problem, the nut loosening prevention device according to the present invention is a nut loosening prevention device that is used when a fastening member is fastened and fixed with a bolt and a nut. A coil spring that is attached in contact with the top surface of the nut, and that the coil spring is elastically deformed, and is formed with an inner diameter that can be locked in the thread groove while expanding in the radial direction; The ring member inserted from the axial direction of the bolt is attached so that the inner surface of the ring member is in contact with the outer periphery of the coil spring, and the ring member is formed in a cylindrical shape having a different diameter on the upper surface and the lower surface and having an inclined outer surface. It is characterized by that.

  According to the nut loosening prevention device of the present invention, the coil spring is elastically deformed to have an inner diameter that can be engaged with the screw groove while expanding in the radial direction, and the coil spring element wire is fitted into the screw groove of the bolt. Because of the structure, the coil spring is pressed in the axial center direction of the bolt by the elastic force of the coil spring, a strong frictional force is generated at the contact portion between the strand and the thread groove, and the strand is firmly fixed to the thread groove. The rotation of the nut in the return direction can be restricted.

  Also, by covering the outer periphery of the coil spring with a ring material and restricting the lifting of the coil spring wire that fits into the thread groove, the coil spring cannot rotate in the return direction of the nut, compared with the case where only the coil spring is mounted It is fixed more securely. Accordingly, it is possible to prevent the nut from loosening even when it is continuously subjected to vibration or impact.

  In addition, the ring material is formed in a cylindrical shape with a different diameter on the upper and lower surfaces and an inclined outer surface, so it cannot be gripped with a tool such as a pipe wrench, and it can be forcibly removed by applying a strong force. Cannot be removed.

  Furthermore, since the shape of the coil spring and the ring material is not complicated, manufacture is also easy.

  The present invention is a loosening prevention tool for the nut 2 used when the fastened member 3 is fastened and fixed by the bolt 1 and the nut 2, and the loosening prevention tool for the nut 2 is composed of a coil spring 4 and a ring material 6. The coil spring 4 is formed with an inner diameter that can be engaged with a screw groove while expanding in the radial direction, and the ring member 6 is formed in a cylindrical shape having a different diameter on the upper surface and the lower surface and having an inclined outer surface. The loosening prevention tool for the nut 2 is attached by screwing the coil spring 4 into the male threaded portion of the bolt 1 and mounting it in contact with the upper surface of the nut 2, and inserting the ring material 6 from the axial direction of the bolt 1. By attaching the inner surface of the material 6 so as to be in contact with the outer periphery of the coil spring 4, loosening of the nut 2 is prevented.

  Hereinafter, the present invention will be described based on examples. For assembling the structure, a tightening method using a bolt 1 and a nut 2 is generally used. As shown in FIG. 1, when the bolt 1 is passed through the through hole of the member 3 and the nut 2 is screwed, the member 3 is fastened by a bolt 1 and a nut 2. When this fastening is completed, the coil spring 4 is screwed into the thread groove of the bolt 1 screwed with the nut 2 from the tip portion 5 and mounted until the tip portion 5 contacts the nut 2 and does not advance any further.

  As shown in FIGS. 2 to 3, the coil spring 4 is slightly smaller than the outer diameter of the bolt 1 and is spirally wound with an inner diameter that can be locked in the thread groove while expanding in the radial direction by elastic deformation. Is formed.

  By screwing the coil spring 4 into the thread groove of the bolt 1, the coil spring 4 is pressed toward the axial center of the bolt 1 by the elastic force of the coil spring 4, and is strong at the contact portion between the element wire 7 of the coil spring 4 and the thread groove. A frictional force is generated, and the wire 7 is firmly fixed to the thread groove of the bolt 1, and the rotation of the nut 2 in the return direction is restricted.

  The element wire 7 of the coil spring 4 may be made of a metal having spring properties. However, since the coil spring 4 is exposed to the atmosphere, it is better to adopt a stainless steel one in order to suppress corrosion due to aging. preferable. Moreover, since the coil spring 4 can obtain the effect of preventing loosening regardless of the number of turns, the number of turns of the coil spring 4 is preferably set according to the length of the bolt 1 to be mounted.

  Further, although the shape of the wire 7 of the coil spring 4 is not shown, a rhombus or polygonal shape other than a circle may be used. Furthermore, if the surface of the wire 7 of the coil spring 4 is roughened or roughened, the adhesion between the screw groove and the contact portion of the wire 7 is improved and the frictional force is increased. Become.

  As shown in FIG. 2, the tip 7 of the wire 7 of the coil spring 4 is processed obliquely, so that the tip 5 is screwed into the gap between the bolt 1 and the nut 2, so that the tip 5 is It becomes a stopper and the nut 2 cannot rotate in the return direction.

  By screwing the coil spring 4 into the thread groove of the bolt 1 as described above, a considerable loosening prevention effect can be obtained, but only the rotation of the nut 2 in the return direction is restricted. Since there is no great difference between the inclination angle of the screw and the inclination angle of the thread, the coil spring 4 may be loosened when subjected to continuous vibration or impact. Therefore, by covering the outer periphery of the coil spring 4 with the ring material 6 and restricting the lifting of the element wire 7 of the coil spring 4 fitted in the thread groove, there is a possibility that the coil spring 4 may rotate even if a continuous rotational force is applied. No loosening prevention device with strong rotational resistance.

  When the ring member 6 is attached so as to cover the outer periphery of the attached coil spring 4, the attachment of the loosening prevention tool becomes more reliable. As shown in FIGS. 4 to 8, the ring material 6 is formed in a cylindrical shape having different diameters on the upper surface and the lower surface and inclined on the outer surface. To be installed. The inner diameter of the ring material 6 is substantially the same as the outer diameter of the coil spring 4 after being mounted in the thread groove of the bolt 1, and the lower end portion of the inner surface of the ring material 6 is chamfered so that it can be easily inserted.

  The inner surface of the attached ring material 6 presses a portion protruding from the groove of the element wire 7 of the coil spring 4 fitted in the screw groove of the bolt 1, and regulates the lifting of the element wire 7. Accordingly, since the element wire 7 of the coil spring 4 does not float up, the coil spring 4 cannot rotate in the return direction of the nut 2 and is fixed more reliably than when only the coil spring 4 is attached.

  Moreover, since the ring material 6 is formed in a cylindrical shape having different diameters on the upper surface and the lower surface and having an inclined outer surface, the ring material 6 cannot be gripped by a tool such as a pipe wrench, and a strong force is applied. It cannot be removed even if it is forcibly removed.

  As described above, in the nut loosening prevention device to which the present invention is applied, the nut 2 is surely loosened even when continuously receiving vibration or impact by the action and effect of the coil spring 4 and the ring material 6. Can be prevented. Moreover, since the shape of the coil spring 4 and the ring material 6 is not complicated, manufacture is also easy.

  Coil spring installation state diagram   Coil spring side view   Top view of coil spring   Side view of the device for preventing loosening of the present invention   Top view of the device for preventing loosening according to the present invention   AA sectional view of the mounting state of the loosening prevention device of the present invention   Top view of ring material   BB cross section of ring material

Explanation of symbols

1 Bolt 2 Nut 3 Member 4 Coil Spring 5 Tip 6 Ring Material 7 Wire

Claims (1)

In the nut loosening prevention tool used when tightening and fixing the fastened member with bolts and nuts,
A coil spring that is screwed into the male thread portion of the bolt and attached to the top surface of the nut;
The coil spring is elastically deformed and formed with an inner diameter that can be locked in a thread groove while expanding in the radial direction.
The ring material inserted from the axial direction of the bolt is attached so that the inner surface of the ring material is in contact with the outer periphery of the coil spring;
The said ring material is formed in the cylindrical shape from which the upper surface and the lower surface differed in diameter, and the outer surface inclined, The nut loosening prevention tool characterized by the above-mentioned.

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