JP3179874U - Fastener consisting of bolt and nut - Google Patents

Abstract

Provided is a fastener comprising a bolt and a nut that can prevent the bolt from falling off due to vibration or the like and can be prevented from falling off and can be tightened strongly.
A shaft portion 3 of a bolt 1 is a main body shaft portion 3a and a thin diameter shaft portion 3b existing on the tip side thereof, and a male screw of a coarse screw 4a is formed on the main body shaft portion, and the thin diameter shaft portion is formed. Forming a male screw for the fine screw 4b, forming a female screw to be screwed to the coarse screw in the tightening nut 5, and forming a female screw to be screwed to the fine screw in the locking nut 6. A fastening tool comprising a bolt and a nut in which a tightening nut is screwed onto the main body shaft portion and a locking nut is screwed onto the small-diameter shaft portion.
[Selection] Figure 3

Description

  The present invention relates to a fastener composed of a bolt and a nut, and more particularly to a fastener composed of a bolt and a nut that are difficult to loosen.

   Conventionally, there is a loosening prevention structure in which two nuts are screwed into one bolt, that is, a so-called double nut. In this case, the locking nut that is screwed onto the bolt is followed by screwing and tightening a locking nut, and the locking nut is prevented from rotating in a loosening direction due to vibration or the like.

  In addition, in this locking structure, both the tightening nut and the locking nut are formed with a female screw of the same pitch, and the male screw of the same pitch is screwed into a bolt formed on the shaft portion, and between the two nuts. The tightening nut is prevented from loosening by the generated frictional force.

  Although the conventional locking mechanism according to such a structure can prevent the tightening nut from loosening to some extent, when a large vibration is applied for a long time, the tightening nut and the locking nut cause a so-called co-rotation and loosen. There was a problem.

  Therefore, in order to solve the above-described problem, Patent Document 1 discloses that both a coarse screw and a fine screw are formed on the shaft portion of the bolt, and a fastening nut is screwed onto the coarse screw. A loosening prevention bolt is disclosed in which a locking nut is screwed onto the screw.

  According to this loosening prevention bolt, the pitch between the tightening nut and the loosening prevention nut is different, so that they do not rotate together, and thus the loosening of the tightening nut can be effectively prevented. .

JP 2003-184848 A

  However, in the loosening prevention bolt disclosed in Patent Document 1 described above, the coarse screw and the fine screw are overlapped and formed in the shaft portion of the bolt, and therefore the thread of the coarse screw is the fine screw. When there is a defective part due to the existence, and when a tightening nut is screwed to the coarse screw, there is a high possibility that the thread will be deformed due to the presence of the defective part, and the tightening nut cannot be tightened strongly. Met. Further, the pitch of the fine screw must be an integral number of the pitch of the coarse screw, that is, one half, one third, etc., so that the fine screw does not interfere with the tightening nut. In addition, high precision is required for its production and design freedom is low.

  The present invention has been made in view of the problems of the background art described above, and its purpose is to prevent the bolt from falling off due to vibration or the like, and to prevent the bolt from falling off, and to tighten it strongly. An object of the present invention is to provide a fastener including a bolt and a nut that can be easily manufactured.

In order to achieve the above object, the present invention is a fastener comprising a bolt and a nut described in the following (1) to (3).
(1) The bolt shaft portion is a main shaft portion and a thin shaft portion existing on the tip side thereof, a male screw of a coarse screw is formed on the main shaft portion, and a male screw of the fine screw is formed on the thin shaft portion. And forming a female screw to be screwed to the coarse screw on the tightening nut, and forming a female screw to be screwed to the fine screw on the locking nut is the tightening nut on the main body shaft portion. A fastener comprising a bolt and a nut, wherein a locking nut is screwed onto the small-diameter shaft portion.
(2) The narrow shaft portion is formed to have a shaft diameter of 60 to 90% of the shaft diameter of the main body shaft portion. Ingredients.
(3) The fine screw formed on the thin shaft portion is formed at a pitch of 30 to 70% of the pitch of the coarse screw formed on the main shaft portion. Or the fastener which consists of a volt | bolt and a nut as described in (2).

  According to the above-described fastener comprising the bolt and nut according to the present invention, the pitch of the tightening nut and the locking nut is different, so that they do not rotate together, so that the tightening nut is effectively loosened. Can be prevented. Moreover, since the coarse screw and the fine screw are not formed overlappingly, the coarse screw has no defective portion, and the tightening nut to be screwed into the coarse screw can be strongly tightened. Further, since the fine screw to which the locking nut is screwed is formed on the small diameter shaft portion on the tip end side of the bolt, the fine screw does not become an obstacle when screwing the tightening nut.

The figure which showed one Embodiment of the fastener which consists of a volt | bolt and a nut which concerns on this invention, Comprising: The conceptual half-section side view which showed the state before screwing a fastening nut and a locking nut on a bolt It is. FIG. 2 is a conceptual half-sectional side view showing a state in which a tightening nut is screwed to a bolt in the fastener including the bolt and the nut shown in FIG. 1. FIG. 2 is a conceptual half-sectional side view showing a state in which a tightening nut and a locking nut are screwed onto the bolt in the fastener including the bolt and the nut shown in FIG. 1.

  Hereinafter, an embodiment of a fastener comprising a bolt and a nut according to the present invention will be described in detail with reference to the drawings.

  1 to 3 show an embodiment of a fastener comprising a bolt and a nut according to the present invention. The bolt 1 illustrated in FIGS. 1 to 3 has a head portion 2 and a shaft portion 3. The head 2 has a substantially hexagonal column shape and is suitable for tightening with a tool such as a spanner or a hexagon wrench. The shaft portion 3 includes a main body shaft portion 3a and a small-diameter shaft portion 3b existing on the tip side thereof, and a male screw of a coarse screw 4a is formed on the main body shaft portion 3a, and the small-diameter shaft The male screw of the fine screw 4b is formed in the part 3b. On the other hand, the tightening nut 5 is formed with a female screw (not shown) that is screwed into the coarse screw 4a formed in the main body shaft portion 3a, and the locking nut 6 has the small-diameter shaft portion 3b. A female screw (not shown) is formed to be screwed into the fine screw 4b formed in the above.

  The small-diameter shaft portion 3b is preferably formed to a shaft diameter of 60 to 90% of the shaft diameter of the main body shaft portion 3a, and more preferably 70 to 85%. This is because, when a thin thin shaft portion of less than 60% is formed, the strength of the thin shaft portion is weakened, and the loosening prevention screwed into the fine screw 4a formed on the thin shaft portion is provided. This is not preferable because it is difficult to secure a sufficient contact area between the nut 6 and the tightening nut 5 screwed into the coarse screw 4a formed in the main body shaft portion. On the other hand, when a thin shaft portion exceeding 90% is formed, the thin shaft portion is formed when the tightening nut 5 is inserted and screwed into the coarse screw 4a formed on the main body shaft portion. This is not preferable because the fine screw 4b may be in the way.

  Further, the fine screw 4b formed on the small-diameter shaft portion is preferably formed at a pitch of 30 to 70% of the pitch of the coarse screw 4a formed on the main body shaft portion, and a pitch of 45 to 60%. More preferably, it is formed. In the case where a fine screw having a narrow pitch of less than 30% is formed, the progress of the locking nut 6 screwed into the fine screw is slow, which is not preferable in practice. On the other hand, when a fine screw having a pitch difference of more than 70% and not much different from the coarse screw is formed, there is a possibility that the tightening nut 5 and the locking nut 6 may rotate together, which is not preferable.

  Note that the coarse screw 4a is not necessarily formed over the entire length of the main body shaft portion, and may be formed only above the main body shaft portion 3a as illustrated. In addition, it is a preferred embodiment that the contact surface between the tightening nut 5 and the locking nut 6 is formed with irregularities or the like that increase resistance to prevent the locking nut 6 from rotating alone. .

When the bolt 1, the tightening nut 5, and the locking nut 6 are used and the object to be fastened is fastened, it may be performed in the same manner as before.
That is, as shown in FIG. 1, first, the shaft portion 3 of the bolt 1 is inserted into the through holes 11a and 12a formed in the members 11 and 12 to be fastened. At this time, a washer 13 is interposed as required.

  Subsequently, as shown in FIG. 2, the members 11 and 12 are fastened by inserting and screwing the tightening nut 5 into the coarse screw 4 a formed on the main body shaft portion 3 a of the bolt 1 and tightening firmly. . At this time, since the fine screw 4b existing at the tip of the bolt 1 is formed on the thin shaft portion 3b having a small diameter, there is no obstacle when the tightening nut 5 is screwed to the coarse screw 4a. Never become. Further, the coarse screw 4a formed in the main body shaft portion 3a is not easily deformed because there is no missing portion, and the tightening nut 5 can be strongly tightened.

  Subsequently, as shown in FIG. 3, a locking nut 6 is inserted into and screwed into the fine screw 4b formed on the small diameter shaft portion 3b of the bolt 1, and the end face of the tightening nut 5 screwed first. Make a strong contact. Thereby, even if vibration is applied over a long period of time, the pitch between the tightening nut 5 and the locking nut 6 is different, so that they do not rotate together, so that the tightening nut 5 is effectively loosened. Can be prevented. Also, it does not prevent the bolt from loosening by crushing the screw thread of the bolt or welding the bolt and nut, etc. If you want to remove the bolt 1, use a tool such as a spanner or hexagon wrench. If the locking nut 6 and the tightening nut 5 are removed from the bolt 1, the bolt 1 can be easily removed.

  As mentioned above, although one embodiment of the fastener consisting of the bolt and nut according to the present invention has been described, the present invention is not limited to the above-described embodiment, and is described in the scope of the utility model registration request. Naturally, various modifications and changes are possible within the scope of the technical idea of the present invention.

  For example, in the above-described embodiment, a so-called hexagonal bolt having a substantially hexagonal column as the head 2 is shown as a bolt. However, a hexagon socket head bolt, an eye bolt, a butterfly bolt, a stud bolt, or the like may be used.

  Fasteners consisting of bolts and nuts according to the present invention are used for fastening parts used in an environment where vibration is applied, for example, parts of household appliances such as automobiles, ships, aircraft, and washing machines equipped with motors. It can be widely used for fastening.

DESCRIPTION OF SYMBOLS 1 Bolt 2 Head 3 Shaft part 3a Main body shaft part 3b Thin diameter shaft part 4a Coarse screw 4b Fine screw 5 Tightening nut 6 Loosening prevention nut 11, 12 Member 11a, 12a Through-hole 13 Washer

Claims (3)

  The bolt shaft portion is a main shaft portion and a small-diameter shaft portion existing on the tip side thereof, a male screw of a coarse screw is formed on the main shaft portion, and a male screw of a fine screw is formed on the thin shaft portion. In addition, a female screw to be screwed to the coarse screw is formed on the tightening nut, and a female screw to be screwed to the fine screw is formed on the locking nut, so that the tightening nut is screwed to the main body shaft portion. A fastener comprising a bolt and a nut, wherein a loosening nut is screwed onto the thin shaft portion.   The fastener according to claim 1, wherein the small-diameter shaft portion is formed to have a shaft diameter of 60 to 90% of the shaft diameter of the main body shaft portion.   The fine screw formed on the thin shaft portion is formed at a pitch of 30 to 70% of the pitch of the coarse screw formed on the main shaft portion. Fasteners consisting of bolts and nuts.

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