JP3054666B2 - Fastener with slack prevention mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fastener used for detachably connecting members such as a plate material.
More specifically, a slack prevention device comprising a nut unit having a bolt of different diameter, a nut non-rotatably disposed in a case body attached to one of the members to be connected, and a detent ring rotatably disposed. It relates to a fastener with a mechanism.

[0002]

2. Description of the Related Art Conventionally, in order to removably connect members such as plate members, a fastener comprising a bolt and a nut which is non-rotatably fixed in a case body attached to one of the members has been used. . Generally, when connecting a member that rotates or moves or a member that receives vibration from other members, the bolt may be loosened due to vibration or the like.
Therefore, as a preventive measure, a spring washer or the like is usually used for the shaft portion of the bolt.

[0003]

However, the conventional method using such a spring washer has an unstable slack preventing effect and is not sufficiently reliable. That is, the principle of using a spring washer to prevent loosening depends on the static friction force between the flat surface of the spring washer and the flat surface of the head of the bolt, and there is a limit to the static friction force. For this reason, for example, when excessive vibration is applied to the member or fine vibration is maintained for a long time, the bolt often becomes loose. Therefore, an object of the present invention is to solve such a problem of the conventional loosening prevention method for a fastener, and to provide a highly reliable fastener with a loosening prevention mechanism based on a completely new principle. is there.

[0004]

A fastener according to the present invention for solving the above-mentioned problems has a shaft portion having a head portion and a screw portion, and a part of the outer periphery of the shaft portion is formed along the axial direction. It has a bolt of different diameter provided with a flat notched surface. Further, it has a case main body having an opening at an upper part, and a mounting part provided with a bolt insertion hole for inserting the different diameter bolt and connected to the opening of the case main body. In the case body, a nut provided with an uneven portion on the upper surface thereof is non-rotatably arranged, and a detent ring in which the uneven portion provided on the lower surface is engaged with the uneven portion of the nut is rotatably arranged. ing. The detent ring is provided with a bolt insertion hole that matches the sectional shape of the different diameter bolt. Further, a compression spring for pressing the detent ring against the nut is provided.

[0005]

The zipper of the present invention has a nut in the case body,
The rotation preventing ring and the compression spring are sequentially housed, and the opening at the upper part of the case main body is covered with a mounting portion to form a nut unit. And the detent ring is pressed by the nut by the compression spring,
The two concavities and convexities are stably engaged with each other. In order to connect the members to be connected by the fastener, first, the nut unit of the fastener is attached to one surface of the connection portion of the member by the mounting portion, and then the nut unit is opposed to the bolt insertion hole provided in the connection portion of each member. A different-diameter bolt is pushed in from the side, and is further inserted through the bolt insertion hole of the fastener mounting portion and the bolt insertion hole of the detent ring in order.
At this time, since the shape of the bolt insertion hole of the detent ring matches the cross-sectional area of the different-diameter bolt, the different-diameter bolt and the detent ring are loosely fitted so as to be vertically movable and relatively non-rotatable.

Then, when the bolt is rotated in the fastening direction,
The different diameter bolt and the detent ring rotate integrally with each other against the pressing force of the compression spring on the upper part thereof. In other words, the non-rotating ring is disengaged from the uneven portion of the nut, and the non-rotating ring rotates integrally with the different-diameter bolt while slightly moving up and down while the uneven portion slides on the uneven portion of the nut. Is screwed to the nut. After the screw connection is completed, the uneven portion of the detent ring and the nut returns to a completely engaged state again, and the bolt having a different diameter is not loosened by the large static friction force obtained by the pressing force of the compression spring. As described above, since the loosening prevention mechanism in the fastener of the present invention is based on the static friction force due to the uneven portion between the detent ring and the nut, the loosening prevention effect is remarkably more than the conventional static friction force between the flat surfaces. Thus, the joined state of the members can be stably maintained.

[0007]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view showing an example of the fastener of the present invention. The fastener 1 basically includes a bolt 2 of different diameter and a nut unit 3. The different-diameter bolt 2 has a head portion 4 having an insertion groove for a driver and a shaft portion 6 on which a screw portion 5 is formed. A cutting surface 7 is provided. FIG.
In the example shown in FIG. 2, a pair of the flat cutout surfaces 7 are provided on a diagonal line on the outer periphery of the shaft portion 6, whereby the cross-sectional shape of the shaft portion 6 as a whole is configured to be substantially elliptical. It is preferable that the screw portion 5 be a multi-thread screw in order to speed up the work of connecting the members.

The nut unit 3 includes a case body 8, a nut 9, a detent ring 10, and a coil-shaped compression spring 1.
1 and an attachment portion 12. The case body 8 is a bottomed cylinder having an opening 13 at the top,
A pair of projections 14 are provided on a diagonal line of the periphery of the opening 13. The protrusion 14 serves as an engaging portion when the mounting portion 12 is mounted as described later. The nut 9 is provided on its upper surface with an uneven portion 15 formed by a number of radially extending ridges having a triangular cross section, and a screw portion formed on its inner peripheral surface. Further, the outer periphery is formed in a quadrangular shape in which each corner is cut off. This nut 9
After being disposed near the bottom of the case main body 8, it is caulked to the case main body 8 from the outside with an appropriate jig, whereby the nut 9 is non-rotatably disposed on the case main body 8.

An anti-rotation ring 10 is provided on its lower surface with an uneven portion 16 formed by a large number of radial ridges aligned with the uneven portion 15 of the nut 9, and at the center thereof, the end surface shape of the different diameter bolt 2. A bolt insertion hole 17 having a substantially elliptical shape is provided. Furthermore, this detent ring 1
The compression spring 11 is arranged above the zero. The mounting portion 12 includes an upper plate 18 and a pair of side plates 19 bent downward from both sides thereof. The upper plate 18 is provided with a bolt insertion hole 20 at the center and a pair of mounting holes 21 near the longitudinal end, and each side plate 19 is provided with a slit 22 with which the projection 13 of the case body 8 is engaged. ing.

FIG. 1 shows a fixing member 3 to be connected.
0 and the mounting member 31 are shown. In this example, a bolt insertion hole 32 for inserting the shaft portion 6 of the different-diameter bolt 2 into a connection portion of the fixing member 30 and a pair of mounting tap holes 33 provided at positions matching the mounting holes 21 of the mounting portion 12. Alternatively, a caulking hole is provided. The inner diameter of the bolt insertion hole 32 is slightly larger than the maximum diameter of the different diameter bolt so that the different diameter bolt 2 can rotate freely. On the other hand, the mounting member 31 is also provided with a bolt insertion hole 34 similar to the bolt insertion hole 32 of the fixing member 30. Reference numeral 35 denotes a spring washer for retaining the bolt, and the different-diameter bolt 2 is inserted into the bolt insertion hole 34 of the mounting member 31 after the shaft 6 is inserted into the spring washer 35.

Next, a method of assembling the nut unit of the fastener shown in FIG. 1 and a method of connecting members using the assembled nut unit and different-diameter bolts will be described. First, the nut 9 is non-rotatably arranged in the case main body 8 by caulking or the like so that the concave and convex portions 15 are on the top. Further, the uneven portion 16 of the rotation preventing ring 10 is
After being arranged so as to mesh with the concave and convex portion 15, the compression spring 11 is arranged above the detent ring 10.
Next, the projections 14 of the case main body 8 are inserted into the slits 22 of the mounting portion 12 by a spring action and engaged therewith, and the mounting portion 12 is connected to the opening 13 of the case main body 8.

FIG. 2 shows this state, in which a nut 9, a detent ring 10 and a compression spring 11 are sequentially housed in a case body 8, and an upper opening 13 thereof is covered by a mounting portion 12 so that the nut Assembled as a unit. Next, the nut unit assembled in this manner is attached to the fixing member 30 (FIG. 1) by using a bolt or the like by the attachment portion 12 thereof, and then the respective bolt insertion holes 34 and 32 are aligned and attached. The member 31 is superimposed on the fixing member 30, and the different-diameter bolt 2 is pushed in from the attachment member 31 side and inserted.

The different diameter bolt 2 is sequentially inserted into the bolt insertion hole 20 of the mounting portion 12 and the bolt insertion hole 17 of the detent ring 10 on the opposite side, and then the different diameter bolt 2 is rotated in the fastening direction by a driver or the like. The rotation preventing ring 10 engaged with the rotation preventing ring 10 is integrally rotated against the pressing force of the compression spring 11 at the upper part thereof. That is, the teeth of the rotation preventing ring 10 and the irregularities 15 and 16 of the nut 9 are disengaged, and the rotation preventing ring 10 moves integrally on the irregularities 15 of the nut 9 and slides integrally with the bolt 2 of a different diameter. Rotate.
Thereby, the different diameter bolt 2 is screwed to the nut 9.
After the screw connection is completed, the detent ring 10 and the nut 9 return to a stable meshing state again, and the uneven portions 15 and 16 of the two.
The large diameter frictional force generated by the action of the compression spring 11 and the compression spring 11 allows the different diameter bolt 2 to stably maintain the connected state of the members without loosening.

[0014]

As described above, according to the fastener of the present invention, each of the uneven portions of the non-rotatably arranged nut and the rotatable detent ring is engaged with each other by engaging the compression spring. Since they are pressed against each other, the different diameter bolts that are inserted into the detent ring so that they cannot rotate relative to each other are allowed to rotate only when forced rotational force is applied by a driver, etc. It is said that rotation is difficult. As described above, the fastener of the present invention having the slack prevention mechanism which is basically different from the conventional one can maintain the connection of the target member stably with high reliability.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an example of the fastener of the present invention.

FIG. 2 is a sectional view showing a state where a nut unit portion of the fastener of FIG. 1 is assembled.

FIG. 3 is a perspective view of a nut unit in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fastener 2 Different diameter bolt 3 Nut unit 4 Head 5 Screw part 6 Shaft part 7 Notch 8 Case body 9 Nut 10 Detent ring 11 Compression spring 12 Attachment part 13 Opening part 14 Protrusion 15 Irregular part 16 Irregular part 17 Bolt Insertion hole 18 Upper plate 19 Side plate 20 Bolt insertion hole 21 Mounting hole 22 Slit 30 Fixing member 31 Mounting member 32 Bolt insertion hole 33 Tap hole 34 Bolt insertion hole 35 Spring washer

Claims (1)

(57) [Claims] A shaft (6) having a head (4) and a screw (5) formed therein, and a flat cutout surface (partly along the axial direction) on a part of the outer periphery of the shaft (6). 7) provided with a bolt (2) having a different diameter, a case body (8) having an opening (13) in an upper part, and a bolt insertion hole (20) for inserting the bolt (2) having a different diameter. Opening of the case body (1
A nut (9), which is non-rotatably disposed within the case body (8) and has an uneven portion (15) for occlusal engagement on its upper surface, and a nut (9) provided on its lower surface; The uneven portion (16) of the nut (9)
A detent ring (10) provided with a bolt insertion hole (17) rotatably disposed in the case body (8) so as to be fitted into the case main body (8) and matching the cross-sectional shape of the different-diameter bolt (2).
And a compression spring (11) for pressing the detent ring (10) against the nut (9).