JP2023130557A - Fastener for half-threaded bolt - Google Patents

Abstract

To provide a nut for a half-threaded bolt which has no risk of the collapse of threads, can easily and properly bring about a fastening state, and is high in a locking effect.SOLUTION: A fastener is constituted of a half-threaded bolt, an auxiliary tool and a bottomed nut. The auxiliary tool is formed into a substantially-cylindrical shape for fitting and fixing a one-way rotating mechanism to a holding body, penetrates the half-threaded bolt without being screwed thereto, and has a fitting part and a flange part provided at an internal peripheral edge of an opening part. The bottomed nut has a female screw part screwed to a male screw part of the half-threaded bolt at an internal peripheral face, a fitting part fit to the fitting part of the auxiliary tool at an external peripheral edge of the opening part at one end, and a flange part at the other end. A fastened product which drills a hole of the bottomed nut having a diameter which is the same as an outside diameter of the female screw part is gripped and fixed to both the flange parts. The one-way rotating mechanism opposes a bolt-axis cylindrical part of the half-threaded bolt at fastening and when the half threaded bolt is rotated in a direction in which the bolt is screwed to the bottomed nut, rotation torque is not transmitted to the one-way rotating mechanism, and the auxiliary tool idles. When the half-threaded bolt is rotated in a screw-out direction, the rotational torque is transmitted to the one-way rotating mechanism via the cylindrical part.SELECTED DRAWING: Figure 1

Description

FIELD OF THE INVENTION The present invention relates to fasteners used in conjunction with semi-threaded bolts to secure objects together.

Generally, when bolts and nuts are tightened and fixed, the axial force (tensile force) generated in the shaft of the bolt and the compressive force (tightening force) generated in the fastened member are integrated, and the two are balanced. The fastened state is maintained.

However, simply screwing a bolt and nut together and tightening them may result in initial loosening due to roughness of the contact part of the screw fastener, or return rotation of the nut due to static or dynamic fluctuations in axial force. Looseness occurs.

Therefore, various efforts have been made in the past. For example, grooved hexagonal nuts, nylon nuts, nuts utilizing a wedge-locking effect, and locking nuts incorporating friction rings are well-known.

Specifically, the technology is characterized in that a clutch piece having a columnar shape with a substantially elliptical cross-sectional shape that contacts the threaded portion of the bolt when the bolt is screwed together is disposed at a position that contacts the threaded portion of the bolt. It has been disclosed (see Patent Document 1).

Japanese Unexamined Patent Publication No. 58-156712 Japanese Patent Application Publication No. 11-117954

However, in the invention described in Patent Document 1, the tip of the clutch piece is crimped onto the male threaded part of the bolt and engaged, so the contact area between the clutch piece and the screw is insufficient, and the effect of preventing loosening and rotation is limited. be. Furthermore, there is a risk of crushing the screw thread.
Therefore, further improvements have been desired in order to create a suitable fastened state without crushing the threads and to obtain a high locking effect.

Therefore, as a result of intensive research to solve this problem, the inventor of the present application obtained a new idea and completed the present invention.

In order to solve the above problem, the invention according to claim 1 is a fastener for a half-threaded bolt whose bolt shaft has a cylindrical part and a male threaded part, the fastener comprises a half-threaded bolt, an auxiliary tool, a bottomed The auxiliary tool is composed of a nut, and the auxiliary tool has a substantially cylindrical shape with a one-way rotation mechanism fitted and fixed to the holder, and is inserted into the half-threaded bolt without being screwed into the inner periphery of the opening on the bottomed nut side. A fitting part and a flange part are provided in the bottomed nut, and the bottomed nut has a female thread part on the inner circumferential surface that is screwed into the male thread part of the bolt shaft of the half-threaded bolt, and a female thread part on the outer circumferential edge of the opening at one end of the bottomed nut. The object to be fastened has a fitting part that fits into the fitting part, a flange part at the other end, and a hole with a large outer diameter in the female thread part of the bottomed nut, which is connected to the flange part of the auxiliary tool and the flange part of the bottomed nut. The one-way rotation mechanism is clamped and fixed by the flange portion of the bottom nut, and when fastened, the one-way rotation mechanism faces the bolt shaft cylindrical portion of the half-threaded bolt, and when the half-threaded bolt rotates in a direction in which the half-threaded bolt is screwed into the bottomed nut. The rotational torque is not transmitted to the one-way rotation mechanism and the auxiliary tool rotates idly, and when the half-threaded bolt rotates in the direction in which it is screwed out from the bottomed nut, the rotational torque is transmitted through the cylindrical portion. It is characterized in that it is transmitted to the one-way rotation mechanism.

Further, in the invention according to claim 2, in the configuration according to claim 1, the one-way rotation mechanism partially protrudes toward the bolt head side of the half-threaded bolt and is fitted and fixed to the holding body, thereby forming an annular shape. The present invention is characterized in that a convex portion is formed, an annular groove is provided around the lower shaft portion of the bolt head, and the annular convex portion fits into the annular groove when fastening.

According to the present invention, it is possible to achieve an appropriate tightening state of bolts and nuts without crushing the threads of male screws, regardless of the skill level of the operator, and to obtain a high loosening prevention effect. became.

It is a figure showing the composition of the fastener for half-threaded bolts concerning one example of the present invention. FIG. 2 is an explanatory diagram showing the structure of an auxiliary tool for a half-threaded bolt fastener according to an embodiment of the present invention. FIG. 2 is a longitudinal cross-sectional view of a half-threaded bolt fastener according to an embodiment of the present invention when in use. 1 is a partial cross-sectional view taken along the line AA of a fastener for a half-threaded bolt according to an embodiment of the present invention.

Embodiments of the present invention will be described below.
Note that the size, shape, and positional relationship of each part constituting the present invention are schematically described for the purpose of promoting understanding of the present invention. Moreover, the materials and materials of each component are disclosed as suitable combinations, and changes that can achieve this effect are not precluded without departing from the spirit of the present invention.

The present invention is a fastening tool for a half-threaded bolt whose bolt shaft is composed of a cylindrical part and a male threaded part, the fastening tool is composed of a half-threaded bolt, a holder, and a bottomed nut, and the fastening tool is made of a half-threaded bolt, a holder, and a bottomed nut. It is clamped and fixed between the holder and the bottomed nut. The details will be explained below.

The half-threaded bolt 10 consists of a bolt shaft consisting of a bolt head 11, a cylindrical portion 12, and a male threaded portion 13.

The auxiliary tool 20 has a substantially cylindrical shape in which a one-way rotation mechanism 21 with a plurality of rollers 21a arranged on the inner peripheral surface is fitted and fixed to a holder 22, and is not screwed into the male threaded part 13 of the half-threaded bolt 10. The fitting portion 23 and the flange portion f1 are provided on the inner peripheral edge of the opening on the bottomed nut 30 side. Note that the fitting portion 23 is not limited to the illustrated shape and structure.

The typical structure and principle of the unidirectional rotation mechanism is, for example, as disclosed in the above-mentioned Patent Document 2, one of the two members concentrically combined with each other rotates in both directions. This mechanism is used to transmit only the rotational movement in one direction to the other member when This mechanism is also called a "one-way clutch", and specifically, for example, a "shell type roller clutch" sold by NSK Ltd. can be used.

The bottomed nut 30 has a female threaded portion 31 on its inner peripheral surface that is screwed into the male threaded portion 13 of the half-threaded bolt 10, and a fitting portion that fits into the fitting portion 23 of the auxiliary tool on the outer periphery of the opening at one end. 32, and a flange portion f2 is provided at the other end.
Note that a release means 33 may be provided as appropriate. This release means 33 is provided to hold the release means 33 with a tool or the like when releasing the state in which the object A is fastened and fixed to the object B using the present invention. Note that the release means 33 is not limited to the illustrated shape and structure.

The procedure for attaching the fixed object A to the target object B (here, the object refers to an object to which the fixed object A is fixed, such as a machine or a building) will be explained. It is assumed that a hole having a larger outer diameter than the female screw portion of the bottomed nut 30 is provided in advance in the object A and the object B.

The cylindrical part of the bottomed nut 30 is inserted through the holes drilled in the fixed object A and the object B, and the auxiliary tool 20 is attached from the opposite side. The fitting part 23 of the auxiliary tool 20 and the fitting part 32 of the bottomed nut 30 are fitted, and the object A and the object B are held between the flanges f1 and f2, and in this state. , insert the half-threaded bolt 10 into the insertion hole h of the auxiliary tool 20, screw the male threaded part 13 into the female threaded part of the bottomed nut, and tighten. The bolt head, flange f1, object A, object B, and flange 2 are integrally fastened together. (Figure 3)

The one-way rotation mechanism 21 faces the cylindrical portion 12 of the bolt shaft, and when the cylindrical portion 12 rotates in one direction (FIG. 4(A)), the rotational torque is not transmitted to the roller 21a, but in the other direction. When rotating (FIG. 4(B)), the rotational torque is transmitted.
In other words, when the half-threaded bolt 10 is screwed in, that is, rotated in the tightening direction (clockwise rotation), the rotational torque is not transmitted to the roller 21a, and the auxiliary body 22 rotates idly, so that the screwing with the male threaded portion 13 is interrupted. However, when an attempt is made to rotate the half-threaded bolt 10 in the direction of unscrewing, that is, loosening (rotation to the left), the rotational torque is transmitted to the roller 21a, and the clutch mechanism is activated, so the half-threaded bolt 10 does not rotate to the left. It is a structure.

After the half-threaded bolt 10 has been fastened, and the bolt head, flange f1, object A, object B, and flange 2 are integrally fastened together, the auxiliary tool 20 must be used to loosen it. The half-threaded bolt 10 will not rotate to the left unless a force that destroys the clutch mechanism is applied.
That is, under normal use conditions, the half-threaded bolt 10 of the present invention will not loosen.

According to this embodiment, the work of tightening the half-threaded bolt is easy, and it is possible to achieve a moderately fastened state and to obtain a high loosening prevention effect.

As a different embodiment, the one-way rotation mechanism 21 partially protrudes toward the bolt head 11 side of the half-threaded bolt and is fitted and fixed to the holder 22 to form an annular convex part P, An annular groove d may be provided around the side shaft portion, and the annular protrusion P may fit into the annular groove d during fastening. With such a structure, high waterproof and dustproof effects can be obtained.

The present invention does not rely on strong tightening force to maintain the fastened state like conventional bolts and nuts, but has a structure that uses a one-way rotation mechanism to prevent loosening after a certain fastened state is achieved. Therefore, it is particularly effective, for example, when the fixed object A or the target object B is made of glass, brick, ceramic, porcelain, or other materials that are brittle against physical forces.
It is also expected to be widely used in locations where periodic inspection is difficult once the tightening work has been completed.

1 Half threaded bolt fastener 10 Half threaded bolt 11 Bolt head 12 Cylindrical part 13 Male threaded part 20 Auxiliary tool 21 One-way rotation mechanism 21a Roller 22 Holder 23 Fitting part 30 Bottomed nut 31 Female threaded part 32 Fitting part 33 Release Means A Fixed object B Target object d Annular grooves f1, f2 Flange portion h Insertion hole P Annular convex portion

Claims (2)

A fastener for a half-threaded bolt whose bolt shaft consists of a cylindrical part and a male threaded part,
The fastener consists of a half-threaded bolt, an auxiliary tool, and a bottomed nut,

The assistive device is
It has a roughly cylindrical shape with a one-way rotation mechanism fitted and fixed to the holding body,
Insert this into the half-threaded bolt without screwing it together,
A fitting part and a flange part are provided on the inner peripheral edge of the opening on the bottomed nut side,

The bottomed nut is
a female threaded portion screwed into the male threaded portion of the bolt shaft of the half-threaded bolt on the inner peripheral surface;
A fitting part that fits into the fitting part of the auxiliary tool is provided on the outer peripheral edge of the opening at one end,
A flange is provided at the other end,

The object to be fastened has a hole with a large outer diameter on the female thread of the bottomed nut,
clamped and fixed between a flange portion of the auxiliary tool and a flange portion of the bottomed nut;

When fastened, the one-way rotation mechanism faces the bolt shaft cylindrical portion of the half-threaded bolt, and when the half-threaded bolt rotates in a direction in which it is screwed into the bottomed nut, the rotational torque is applied to the one-way rotation mechanism. The auxiliary tool idles without being transmitted;
A fastener for a half-threaded bolt, in which when the half-threaded bolt rotates in a direction in which it screws out from the bottomed nut, the rotational torque is transmitted to the one-way rotation mechanism via the cylindrical portion.
The one-way rotation mechanism partially protrudes toward the bolt head side of the half-threaded bolt and is fitted and fixed to the holding body to form an annular convex portion,
An annular groove is provided around the lower neck shaft portion of the bolt head,
The fastener for a semi-threaded bolt according to claim 1, wherein the annular protrusion fits into the annular groove during fastening.

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