JPH05187427A - Fastener with loosening prevention mechanism - Google Patents

Abstract

PURPOSE:To provide a reliable fastener with a loosening prevention mechanism, for coupling members. CONSTITUTION:A fastener is composed of a different diameter bolt 2 in which a flat cut-out face 7 is formed in one part of the outer periphery of a shank part 5, and a nut unit 3. The nut unit 3 has a nut 9 disposed unrotatably in a casing body 8, and a rotation checking ring 10 disposed rotably therein, recesses and protrusions of these nut 9 and the ring 10 being engaged with each other and being urged by a compression spring 11. Accordingly, the different diameter bolt 10 inserted in the ring 10, unrotatably relative to each other, may not be rotated due to a large static frictional force between the recesses and the protrusions unless a forced torque is applied thereto by a driver or the like.

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 plate materials,
More specifically, a loosening prevention composed of a bolt unit having different diameters, a nut non-rotatably arranged in a case body attached to one of members to be connected, and a rotation stop ring rotatably arranged. For fasteners with a mechanism.

[0002]

2. Description of the Related Art Conventionally, in order to detachably connect members such as a plate member, a fastener composed of a bolt and a nut fixed to one of the members and non-rotatably fixed in a case body has been used. .. Generally, when a member that rotates or moves, or a member that receives vibration from another member is connected, 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 on the shaft portion of the bolt.

[0003]

However, in the conventional method using such a spring washer, the slack preventing effect is unstable and the reliability is not sufficient. That is, since the principle of preventing loosening by using the spring washer depends on the static frictional force between the flat surface of the spring washer and the flat surface of the head of the bolt, the static frictional force is limited. Therefore, for example, when excessive vibration is applied to the member, or when fine vibration lasts for a long period of time, the bolt often loosens. Therefore, the present invention has an object to solve the problems of the loosening prevention method in such a conventional fastener, and provides a highly reliable fastener with a loosening prevention mechanism based on a completely new principle. is there.

[0004]

A fastener of the present invention for solving the above-mentioned problems has a shaft portion formed with a head portion and a screw portion, and a part of the outer circumference of the shaft portion along the axial direction. It has a different diameter bolt with a flat cut surface. Furthermore, it has a case main body having an opening at the top, and a mounting portion 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 its upper surface is non-rotatably arranged, and a rotation stop ring in which the uneven portion provided on the lower surface is engaged with the uneven portion of the nut is rotatably arranged. ing. A bolt insertion hole that matches the cross-sectional shape of the different diameter bolt is provided in the detent ring. Further, it is characterized in that a compression spring for pressing the detent ring against the nut is provided.

[0005]

[Function] The fastener of the present invention has a nut in the case body,
The rotation preventing ring and the compression spring are accommodated in this order, and the opening of the case body is covered by the mounting portion to form a nut unit. And the detent ring is pressed against the nut by the compression spring,
Both the uneven parts are occluded stably. In order to connect each member to be connected by this fastener, first attach the nut unit of the fastener to one surface of the connecting portion of the member by its mounting portion, and then reverse the bolt insertion hole provided in the connecting portion of each member. Push the different diameter bolt from the side, and then insert it into the bolt insertion hole of the attachment part of the fastener and the bolt insertion hole of the rotation stop 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 vertically movable and relatively non-rotatably fitted.

Then, when the bolt is rotated in the fastening direction,
The different-diameter bolt and the detent ring rotate integrally against the pressing force of the compression spring on the upper part thereof. In other words, the non-rotating ring and the concavo-convex part of the nut are disengaged from each other, and the concavo-convex part rotates up and down slightly while sliding on the concavo-convex part of the nut and rotates integrally with the different diameter bolt. Is screwed to the nut. After the screw connection is completed, the concavo-convex portion of the detent ring and the nut returns to a completely occlusal state, and the large static friction force obtained by the pressing force of the compression spring does not cause the different diameter bolt to loosen. As described above, the slack prevention mechanism in the fastener of the present invention is based on the static friction force due to the uneven portion between the rotation preventing ring and the nut, and therefore the slack prevention effect is more remarkable than the conventional static friction force between flat surfaces. It is improved, and the bonded state of the members can be stably maintained.

[0007]

Embodiments of the present invention will now 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 is basically composed of a different diameter bolt 2 and a nut unit 3. The different-diameter bolt 2 has a head portion 4 having a screw-in groove for a driver and a shaft portion 6 on which a screw portion 5 is formed. A part of the outer periphery of the screw portion 5 has a flat notch along the entire axial length. A cut face 7 is provided. Figure 1
In the example shown in (1), a pair of the flat cut surfaces 7 are provided on the diagonal line of the outer periphery of the shaft portion 6, so that the overall sectional shape of the shaft portion 6 is formed into a substantially elliptical shape. In addition, in order to speed up the connecting work of the members, it is preferable that the screw portion 5 is a multiple thread screw.

The nut unit 3 includes a case body 8, a nut 9, a rotation stop ring 10, and a coiled compression spring 1.
1 and a mounting portion 12. The case body 8 is a bottomed cylinder having an opening 13 at the top,
A pair of protrusions 14 are provided on the diagonal line of the peripheral edge of the opening 13. The projection 14 serves as an engaging portion when the mounting portion 12 is mounted as described later. The nut 9 is provided with a concavo-convex portion 15 formed on the upper surface thereof with a large number of radial convex ridges having a triangular cross section, and a screw portion is formed on the inner peripheral surface thereof. Further, the outer periphery thereof is formed in a quadrangular shape in which each corner portion is chamfered. This nut 9
Is placed near the bottom of the case body 8 and then crimped to the case body 8 from the outside with an appropriate jig, whereby the nut 9 is non-rotatably arranged on the case body 8.

The anti-rotation ring 10 is provided on its lower surface with a concavo-convex portion 16 formed by a large number of radial convex lines which are aligned with the concavo-convex portion 15 of the nut 9, and at the center thereof, the end face shape of the different diameter bolt 2 is provided. Is provided with a substantially elliptical bolt insertion hole 17. Furthermore, this detent ring 1
A compression spring 11 is arranged on the upper part of 0. The mounting portion 12 is composed of 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 in the center and a pair of mounting holes 21 near the ends in the longitudinal direction, and each side plate 19 is provided with a slit 22 with which the projection 13 of the case body 8 engages. ing.

FIG. 1 shows a fixing member 3 which is a member to be connected.
0 and 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 the connecting 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. Or, 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 freely rotate. 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 preventing slipping out, and the different diameter bolt 2 is inserted into the bolt insertion hole 34 of the mounting member 31 after the shaft portion 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 by using the assembled nut unit and different diameter bolts will be described. First, the nut 9 is arranged in the case body 8 so as to be non-rotatable by caulking or the like so that the uneven portion 15 faces upward. Further, the rotation stopper ring 10 is provided with the concave and convex portion 16 of the nut 9
After being arranged so as to mesh with the uneven portion 15 of the above, the compression spring 11 is arranged above the detent ring 10.
Next, the protrusions 14 of the case body 8 are inserted into and engaged with the slits 22 of the mounting portion 12 by a spring action, and the mounting portion 12 is connected to the opening 13 of the case body 8.

FIG. 2 shows this state, in which the nut 9, the rotation-stop ring 10 and the compression spring 11 are housed in the case body 8 in order, and the opening 13 at the upper part thereof is covered by the mounting portion 12 to cover the nut. It is assembled as a unit. Next, the nut unit assembled in this manner is attached to the fixing member 30 (FIG. 1) by means of the attachment portion 12 using bolts or the like, or by caulking, and then the respective bolt insertion holes 34, 32 are attached in alignment. The member 31 is superposed on the fixing member 30, and the different diameter bolt 2 is pushed in from the mounting 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 rotation stop 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. Then, the detent ring 10 engaged with the non-rotatable relative thereto is rotated integrally against the pressing force of the compression spring 11 on the upper part thereof. That is, the engagement between the anti-rotation ring 10 and the concavo-convex portions 15 and 16 of the nut 9 is disengaged, and the anti-rotation ring 10 slides up and down on the concavo-convex portion 15 of the nut 9 to be integrated with the different diameter bolt 2. To 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 the stable meshing state again, and the uneven portions 15 and 16 of both
Due to the large frictional force due to the action of the compression spring 11, the different-diameter bolt 2 does not loosen and stably maintains the joined state of the members.

[0014]

As described above, according to the fastener of the present invention, the concavo-convex portions of the non-rotatably arranged nut and the rotatably arranged detent ring are engaged with each other by the compression spring. Since they are pressed against each other, the different-diameter bolts inserted into the non-rotating ring so that they cannot rotate relative to each other are allowed to rotate only when the driver is given a compulsory rotating force. It is said to be difficult to rotate. As described above, the fastener of the present invention having the loosening prevention mechanism which is different in principle from the conventional one can maintain the connection of the target members stably with high reliability.

[Brief description of drawings]

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

2 is a cross-sectional view showing a state in which a nut unit portion of the fastener shown in FIG. 1 is assembled.

FIG. 3 is a perspective view of a nut unit portion of FIG.

[Explanation of symbols]

 1 fastener 2 different diameter bolt 3 nut unit 4 head part 5 screw part 6 shaft part 7 notch part 8 case body 9 nut 10 non-rotating ring 11 compression spring 12 mounting part 13 opening part 14 protrusion 15 uneven part 16 uneven 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)

[Claims] 1. A head (4) and a shaft portion (6) formed with a screw portion (5), and a flat notched surface (axially) along a part of the outer periphery of the shaft portion (6). And a case body (8) having an opening (13) in the upper part, and a bolt insertion hole (20) for inserting the different diameter bolt (2). Case body opening (1
3), a mounting part (12), a nut (9) non-rotatably disposed in the case body (8) and provided with a concavo-convex part (15) on its upper surface, and a nut (9) on its lower surface. The uneven portion (16) of the nut (9)
Anti-rotation ring (10) rotatably disposed in the case body (8) by being engaged with and provided with a bolt insertion hole (17) that matches the cross-sectional shape of the different diameter bolt (2)
A fastener with a loosening prevention mechanism, comprising: a compression spring (11) for pressing the rotation preventing ring (10) against the nut (9).