JP2003148440A - Nut drop-off prevention device for fasteners consisting of bolts and nuts - Google Patents

Abstract

(57) [Problem] To provide a mechanism for reliably preventing a nut from falling off a bolt due to external vibration or the like. SOLUTION: A bolt 1 having a groove 13 at an end of a shaft rod 11 having a screw part 12, a nut 2 screwed to the screw part 12, and a through hole 31 through which the shaft rod 11 is inserted at the center. And a stop ring 3 made of an elastic plate on the periphery of which a locking claw 32 for locking the groove 13 is protruded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nut drop-off preventing device for a fastener composed of a bolt and a nut,
In particular, external vibration is added to the frequency, and the nut loosens and falls off, which may lead to a serious accident.For example, a nut drop prevention device that is effective in a fastener that fastens each component in a train line support mechanism. Regarding

[0002]

2. Description of the Related Art Generally, many fasteners consisting of bolts and nuts are used as connecting means or stopping means in a train line support mechanism or the like. Frequent and intense external vibration is applied due to wind pressure, which causes the fastener to loosen gradually, and eventually the nut may fall off the bolt, causing a serious accident.

Therefore, conventionally, a split pin insertion hole penetrating in the diametrical direction is provided at the free end portion of the bolt, and a nut is screwed into the bolt to fasten the object to be fastened, and then the split pin is inserted into the insertion hole. Then, the lower end of the split pin was opened from the split groove to prevent the nut from falling off the bolt.

[0004]

However, in the fastening work of the bolt and the nut, an operator often fails to insert the split pin into the insertion hole or completely inserts the split pin into the insertion hole. However, there was a problem in that the work of opening the lower end of the split pin was forgotten, and therefore the split pin was pulled out from the bolt, causing the nut to fall off.

[0005]

Therefore, in order to solve the above-mentioned conventional inconvenience, a bolt having a groove in the vicinity of the free end of a shaft rod having a screw portion, and a screw portion of the shaft rod. When the shaft rod is inserted through the through hole, the nut that is screwed into and the through hole through which the shaft rod is inserted are provided in the center part.
The leading edge is composed of a stop ring made of an elastic plate provided with a plurality of locking claws protruding from the recessed groove.

In the above description, preferably, the diameter of the free end of the shaft rod continuing to the groove is equal to or smaller than the root diameter of the threaded portion and larger than the diameter of the groove. The diameter.

Further, the locking claw of the stop ring is inclined in advance to the side opposite to the insertion direction with respect to the shaft rod.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. 1 is a plan view of a bolt, FIG. 2 is a plan view of a retaining ring, and FIG. 3 is a side view of the retaining ring.

The bolt 1 has a regular hexagonal head 1 at one end.
The shaft rod 11 having 0 is provided with the threaded portion 12, and the fastened bodies A and B (see FIG. 4) to be fastened are fastened by the nut 2 in the vicinity of the free end portion of the shaft rod 11. The groove 13 is provided, leaving the necessary and sufficient screw portions.

Further, the free end portion 11a of the shaft rod 11 which is continuous with the concave groove 13 is preferably equal to the root diameter a of the threaded portion 12 but smaller than that, and the concave portion The groove 13 is formed with a diameter c larger than the diameter b of the groove 13.

The stop ring 3 is composed of a circular spring plate 30, and has a through hole 31 in the center thereof, the through hole 31 having a size sufficient to allow the shaft rod 11 of the bolt 1 to be inserted therethrough, and the peripheral edge of the through hole 31. In addition, when the shaft rod 11 is inserted into the through hole 31, a plurality of locking claws 32 are provided so that the leading edges are locked to the inner wall surface of the concave groove 12, and the locking claws 32 are preferably As is apparent from FIG. 3, the through hole 31 is pre-inclined on the side opposite to the arrow indicating the direction of insertion into the shaft rod 11.

FIG. 4 is a plan view showing a state in which the fastened bodies A and B are fastened to the bolt 1 by the nut 2 and the retaining ring 3 is mounted. After the fastened bodies A and B are inserted into the shaft rod 11 of the bolt 1, the nut 2 is screwed into the threaded portion 12 and tightened.

Next, when the stop ring 3 is inserted into the free end portion 11a of the shaft rod 11 through the through hole 32, the locking claw 33 becomes
While passing through the free end portion 11a, while being in pressure contact with the outer periphery of the free end portion 11a, it is greatly inclined in the inclination direction, and then the locking claw 33
Intervenes in the groove 13, and the leading edge thereof is one corner p formed by the groove 13 as shown in FIG.
Therefore, the stop ring 3 is reliably prevented from moving in the direction opposite to the insertion direction with respect to the shaft rod 11.

Therefore, in the state shown in FIGS. 4 and 5 in which the stop ring 3 is mounted, the nut 2 is reliably prevented from falling off the shaft rod 11.

In the above embodiment, the stop ring 3 is attached to the shaft rod 1.
1 illustrates the case where the stop ring 3 is pressed against the end surface of the nut 2 in a state of being mounted on the connector 1. In this configuration, the stop ring 3 is elastically pressed against the end surface of the nut 2. By virtue of this, the effect of preventing the nut 2 from loosening is exerted, but with the stop ring 3 attached, the stop ring 3 does not necessarily have to be in pressure contact with the end surface of the nut 2 in the tightened state, and in this case as well. Therefore, the nut 2 can be reliably prevented from falling off.

[0016]

As described above in detail, according to the present invention, the nut is removed from the shaft rod of the bolt by a very simple operation of simply pushing the stop ring from the free end of the bolt through the through hole. Has the advantage that it can be reliably prevented.

In particular, according to the second aspect of the invention, since the nut can be easily fitted to the free end portion of the shaft rod, the end portion serves as a guiding function, and the nut is fitted to the screw portion. There is an advantage that the screwing operation becomes easy.

According to the third aspect of the present invention, since the locking claws are pre-inclined to the side opposite to the insertion direction with respect to the shaft rod, the operation of inserting the retaining ring with respect to the shaft rod is facilitated. Have.

[Brief description of drawings]

1 is a plan view of a bolt

FIG. 2 is a plan view of a retaining ring.

FIG. 3 is a side view of the retaining ring.

FIG. 4 is a plan view showing a usage state.

FIG. 5 is an enlarged sectional view of a main part.

[Explanation of symbols]

1 volt 2 nuts 3 stop ring 11 Axle 11a free end 12 screw part 13 groove 31 through holes 32 locking claw

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoshi Nasu             2-2-2 Yoyogi, Shibuya-ku, Tokyo Tohnichi             Inside the passenger railway (72) Inventor Tetsuo Tsuburaya             2-2-2 Yoyogi, Shibuya-ku, Tokyo Tohnichi             Inside the passenger railway (72) Inventor Sugio Kasuga             1-3-30 Hiromachi, Shinagawa-ku, Tokyo, Japan             Line Industry Co., Ltd. (72) Inventor Teruo Sato             Stock market association, 3-14-2 Ueno, Taito-ku, Tokyo             Inside Yasuda Factory (72) Inventor Hajime Miyata             Stock market association, 3-14-2 Ueno, Taito-ku, Tokyo             Inside Yasuda Factory

Claims (3)

[Claims] 1. A bolt having a groove formed in the vicinity of a free end of a shaft rod having a threaded portion, a nut screwed into the threaded portion of the shaft rod, and a threaded member through which the shaft rod is inserted through a central portion. It has a hole, and at the periphery thereof, a stop ring made of an elastic plate having a plurality of locking claws protruding from the leading edge when the shaft rod is inserted into the through hole. A device for preventing nuts from falling out in a fastener consisting of a characteristic bolt and nut. 2. The diameter of the free end portion of the shaft rod which is continuous with the groove,
The nut dropout prevention device for a fastener comprising a bolt and a nut according to claim 1, wherein the diameter is equal to or smaller than the root diameter of the threaded portion and is larger than the diameter of the groove. 3. The nut fall prevention device for a fastener comprising a bolt and a nut according to claim 1 or 2, wherein the locking claw of the stop ring is inclined in advance to the side opposite to the insertion direction with respect to the shaft rod.