JPH0516407Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The invention relates to a bolt with a locking device to prevent loosening. More specifically, after the bolt body is tightened, the built-in fixing bolt is further tightened. This invention relates to a bolt with a locking device that can completely lock the bolt body by tightening the bolt.

[Prior Art] In general, bolts that fasten objects together, that is, bolts commonly called hexagonal bolts or hexagon socket head bolts, must not easily loosen after being tightened.

In particular, when used in places subject to high vibrations and shocks, different loosening prevention measures are required in addition to normal tightening.

To prevent the bolt from loosening, a flat washer, a spring washer, a toothed washer, or the like is inserted between the rotating part, which is the head of the bolt, and the material to be tightened.

In addition, in the case of a through bolt, a double nut is used to prevent loosening, or a set screw (holding screw) is used to lock the tightening body (the part corresponding to the nut) and the threaded part of the bolt by biting into it, or
Loosening is prevented by applying adhesive between the threaded part or rotating part and the material to be tightened.

However, in this type of technology, the locking force using washers is only due to the contact resistance between one side of the rotating part of the bolt and the seat surface of the tightened material, so the locking force is greater than the force used to tighten the bolt. (It is effective against vibration to a certain extent, but it is not completely locked), and on the contrary, the bolt may be damaged by the washer, or the rotational force (tightening force) of the bolt may be damaged. Since the strength of the locked state is influenced by the strength of the locking state, the overall strength of the bolt and the tightening body and the strength of the threaded portion are required.

In addition, in the case of a double nut, there are restrictions on where it can be used, and the bolt must be tightened and then returned to its original position to lock, which weakens the tightening force of the bolt.

Furthermore, when using set screws, there are problems such as restrictions on where they can be used, complicated machining, and damage to the threaded parts.Also, in the case of adhesives, although they are relatively easy to use, the locking force is weak. If an attempt was made to increase the locking force, the bolt could not be loosened easily if necessary.

Therefore, conventionally, a bolt body having a rotating part and a threaded part for tightening, a hole provided in the center of the bolt body, a tapered threaded hole continuous with the hole, and a center line of the threaded part of the bolt body. A bolt with a locking device (Utility Application No. 62-152898 ).

[Problems to be solved by the invention] Even with the conventional technology, it is not limited to the location of use, does not damage the material to be tightened, does not require processing of the tightening body on the nut side, and is easy to use. However, due to its structure, it is difficult to manufacture a tapered screw, and it is difficult to make a tapered screw because it is attached to the base body, which is the tightening body. There is a problem in that there is a risk of damage to the threaded portion of the base body.

The present invention was devised in view of these problems of the conventional technology, and its purpose is to inherit the advantages of the conventional technology as is, improve its defects, and improve manufacturing efficiency. The purpose of the present invention is to provide a bolt with a locking device that can be easily and reliably used repeatedly.

[Means for Solving the Problems] In order to achieve the above object, the bolt with a locking device of the present invention has a penetrating internal threaded part formed in the center in the opposite thread direction from the external threaded part, and a distal end with a distal end. A bolt body consisting of an outer tapered portion that gradually becomes smaller in diameter toward the bolt body, an annular body consisting of an inner tapered portion that matches the tapered portion of the bolt body, and a split groove provided in the axial direction, and the annular body is inserted into the bolt body. It is characterized in that it is formed of a fixing bolt having a reverse external threaded part that is fitted and held and screwed into the internal threaded part, and has a turning part at the center of the tip of the reverse external threaded part.

Further, the above-mentioned dividing groove portion can be provided in one to four divided shapes.

In addition, when there is a plurality of the above-mentioned groove parts, for example,
An annular groove may be provided on the outer periphery of the annular body, and the elastic body may be inserted into the annular groove so that the annular body is always integrated toward the center.

Furthermore, the fixing bolt can hold the annular body using the collar and a holding device such as a snap spring.

[Function] The bolt body is screwed into a threaded portion provided on the base body to fix the tightened body in the same way as a general bolt.

Then, if the fixing bolt, whose thread direction is opposite to that of the base thread, is further turned in the tightening direction of the bolt body, the fixing bolt will rise or try to be pulled out from the bolt body, but at that time At the same time, the annular body rotatably held by the fixing bolt also tries to rise.

However, since the inner tapered portion of the annular body contacts the outer tapered portion of the bolt body, the annular body guided by the tapered portion tends to expand in the outer circumferential direction.

The outer circumferential wall of this enlarged annular body is pressed against the inner circumferential wall of the lower unused portion of the base threaded part, preferably the inner circumferential wall of the unthreaded hole formed continuously in the base threaded part, so that the bolt body and the base body are press-fitted and fixed via a fixing bolt and an annular body.

[Example] An example of this invention will be described with reference to the drawings.
The figure is a sectional view of the main part taken along the line A-A in FIG. 1.

The bolt body 1 is a hexagonal head bolt, and at its axial center there is an internal threaded part 4 that passes through and has a thread direction opposite to that of the external threaded part 9. It is formed from an outer tapered portion 5 whose diameter gradually decreases toward the bottom (in FIG. 1).

The fixing bolt 2 has a reverse external threaded part 10 which is screwed into the internal threaded part 4, a hexagonal hole turning part 7 at the center of the tip of the threaded part (upper part in FIG. 1), and a rotating part 7 at the other end (in FIG. (lower part) is formed from a hexagonal head-shaped flange 11.

The annular body 3 has an inner tapered part 6 that matches the outer tapered part 5, and is divided into two parts by two groove parts 8, and is inserted into the fixing bolt 2 and connected to the collar part 11 and the shaft. It is held by a holder 12 which is a C-shaped retaining ring.

An outer circumferential groove 1 is formed on the outer circumference of this annular body 3.
6, which is always springed toward the center by a spring snap spring (not shown) and is integrally formed.

The base body 13 has a base threaded portion 14 that is screwed into the external threaded portion 9 of the bolt body 1, and a pilot hole of the base threaded portion 14 is provided at the tip (lower side in FIG. 1) of the base threaded portion 14. A non-threaded hole portion 17 is formed.

15 is a material to be tightened through which the bolt body 1 is inserted.

The present invention is not limited to the above embodiments; for example, the material of the annular body does not have to be the same as that of the bolt and can be freely selected, and the dividing groove part is not cut by leaving the inner peripheral edge. Integrity may be maintained in this manner, and the annular outer periphery may be provided with a non-slip finish such as knurling.

[Effects of the invention] As described above, in the present invention, since the bolt body is press-fixed by the lower part of the threaded part of the base, which is unrelated to tightening, and the outer circumference of the annular body, it is of course possible to securely lock the bolt body. Since unreasonable stress is not applied to the external threaded portion of the device or the necessary threaded portions of the base, all of the threaded portions will not be damaged even after repeated use, and durability can be improved.

Further, since no screws are required at the press-contact portion between the annular body and the base body, the number of threaded portions of the base body may be small, and furthermore, there is no need to cut the threaded portions, so thread processing is easy.

Furthermore, all of the threaded parts can be straight general threads, and no tapered threads are required, so manufacturing is easy, and since the precision of the tapered part does not require precision, it is more suitable for mass production and can be provided at a lower cost. It has the effect that it can be done.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a main part showing the state of use, and FIG. 2 is a sectional view taken along the line A--A in FIG. 1. 1...Bolt body, 2...Fixing bolt, 3...
Annular body, 4...Inner threaded part, 5...Outer tapered part,
6... Internal taper part, 7... Rotating part, 8... Division groove part, 9... External threaded part, 10... Reverse external threaded part, 11
... Flange, 12 ... Holder, 13 ... Base, 14
... Base threaded portion, 15 ... Material to be tightened, 16 ... Outer circumferential groove, 17 ... Unthreaded hole.

Claims (1)

[Scope of utility model registration request] A bolt body 1 consisting of a penetrating internal threaded part 4 formed at the center in a direction opposite to the external threaded part 9 and an external tapered part 5 whose tip part gradually becomes smaller in diameter toward the tip; an annular body 3 consisting of an internal taper part 6 that matches the taper part 5 and a split groove part 8 provided in the axial direction; and a reverse external thread part that inserts and holds the annular body 3 and is screwed into the internal thread part 4. 10 and a fixing bolt 2 having a turning part 7 at the center of the tip of the reverse external thread part 10.