JPH06229408A - Prevention of screw miss of fastening - Google Patents

Abstract

PURPOSE:To make a soft material swell out to the inside of an opening so as to judge whether fastening is missed or not by providing a transmissive hole opening axially to an opposing face formed by a fastener and a material to be fastened and arranging the soft material adjacent to the transmissive hole. CONSTITUTION:A ringed recessed part 24 is formed around the circumferential part 23 of a flat washer 20 and a soft material 14 is contained in the recessed part 24. When such a flat washer 20 is arranged between a bolt 11 and a nut 12, and a material 10 to be fastened and tightened by a tool, the soft material 14 arranged between the flat washer 20 and a conductive belt 10 by its tightening force is strongly pressed by both and flows to the circumference, while deforming into flat. At that time a part of the soft material 14 flows into an axial transmissive hole 25 formed by the flat washer 20 so as to be filled there. Thereby when an assembly is completed, swelling or non-swelling of all the bolts is confirmed by visual inspection and whether fastening is missed or not can be judged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bolt used to fasten electric wiring for strong electric power in a power plant or a substation, or when assembling or maintaining important safety parts such as a railway vehicle or a road surface vehicle. The present invention relates to a method for preventing rubbing that facilitates detection of forgetting to tighten a screw fastening tool such as a nut or nut.

[0002]

2. Description of the Related Art Conventionally, in a work in which forgetting to tighten bolts and nuts is a problem, an inspector or an inspection robot is used to inspect whether or not the user forgets to tighten the bolt after completion of the tightening work. In other words, inspectors and inspection robots must be equipped with fastening tools and torque wrenches to inspect the bolts and nuts one by one, and whether or not they are fastened with a predetermined tightening torque. Has been done.

[0003]

However, the introduction of the inspection robot requires a large amount of capital investment, and it takes a lot of time to mount it. It is not effective even if it is introduced in small-scale production or maintenance work that is generally performed individually.
Therefore, in the past, reliance on inspection by human sensation was used exclusively, but if the person who performed the fastening work and the person who performs the inspection were performed by the same person, the re- inspection accuracy would be poor due to the person's feelings and habits. It is easy to become ゝ. In addition, a large number of workers are required to perform the inspection by another person, which increases the cost for production and maintenance. Further, if the inspection is insufficient, sometimes a problem occurs in which a strong electric current is caused to flow between the insufficiently connected electric wires to burn the wiring or cause a serious accident.

[0004]

SUMMARY OF THE INVENTION The present invention solves such a problem by providing a screw fastening tool composed of a bolt, a nut or a washer and an object to be fastened by the screw fastening tool. On the other hand, a through hole that opens in the axial direction is provided in the relative surface formed by the fastener and the object to be fastened, a soft material is arranged in the vicinity of the through hole, and when the relative surface is pressed,
It is characterized in that the soft member is swollen into the opening, and the presence or absence of the swollenness is visually checked to see whether or not the tightening has been forgotten to judge whether or not the loosening has been missed.

[0005]

[Function] When a tightening object such as a bolt or a nut is inserted into a bolt hole provided in an object to be tightened and tightened by a tool, the tightening force causes the soft material on the relative surface to be tightened out from the relative surface. Flow into the axial direction, but part of it flows into the axial opening provided on the relative surface. Therefore, when confirming the tightening, the opening is closely watched and it is visually confirmed whether or not the soft material is flowing therein. If it has not flowed in, it is determined that tightening has been forgotten, and if it has flowed in, it is determined that it has been securely fastened.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. In FIG. 1, reference numeral 10 denotes a plurality of objects to be fastened which are fastened to each other, for example, a conductive band which is an electric wire for energization used in a power plant or a substation. Several of the conductive bands 10 are superposed on each other, and as shown in FIG. 2, bolt holes are provided at their intersecting portions, and the conductive bands 10 are firmly connected by a screw fastening tool S including a bolt 11, a nut 12, and a washer 20. It is worn. As a result, a large electric resistance such as a contact resistance is not formed between them, and heat generation and loss are not caused by energization.

In this embodiment, the conductive bands 10, 10
As shown in FIGS. 2 and 3, the screw fastening tool S for fastening the
The bolt 11 and the nut 12, or the plain washer 20 interposed between them. Here, the plain washer 20 is provided between the conductive band 10 and the head of the bolt 11 as shown in FIG.
Alternatively, as shown in FIG. 2, it is interposed between the conductive band 10 and the nut 12. The plain washer 20 has a relative surface that faces the bolt 11 and the nut 12 around the central bolt hole 21, that is, an annular fastening portion 22 that receives a fastening force from the screw fastener S, and a peripheral portion that is continuous with the outer periphery thereof. It has a surface of 23.

The peripheral washer 23 of the plain washer 20 is formed with an annular recess 24 on one of the upper and lower surfaces for accommodating a soft material described later. The flat washer 2 is placed in the recess 24.
When 0 receives a fastening force, a plurality of axial through holes 25 are formed in the circumferential direction so as to swell the soft material. As shown in FIG. 4, the form of the through hole 25 is not necessarily a circular hole, and a notch may be formed in the outer peripheral surface of the peripheral edge portion 23 and used as the through hole as it is.
The shape of the recess 24 for accommodating the soft material 14 may be formed by plastically deforming a relatively thin steel plate forming a flat washer as shown in FIG. 4, and as shown in FIG. It may be formed by pressing a part of a relatively thick steel plate to form an annular recess and further by cutting.

Reference numeral 14 denotes a soft material disposed inside the recess 24, specifically, a rubber-like O-ring which is an industrial sealing member. The soft material does not necessarily have to be rubber-like, and may be powdery or gelatinous. That is, it is required to be elastically or plastically deformable and to have a slight fluidity.

As shown in FIG. 3, the flat washer 20 formed as described above is used for fixing the bolt 11 and the nut 12 and the object 1 to be fastened.
When placed between 0 and tightened with a tool not shown,
Due to the tightening force, the soft material 14 disposed between the plain washer 20 and the conductive band 10 is strongly pressed by both, and is deformed flat and flows to the surroundings. At this time, a part of the soft material 14 flows into the through hole 25 in the axial direction and fills the hole, as shown in FIG. Therefore, after completion of the assembly, it is possible to easily determine whether or not the tightening has been forgotten by visually checking the presence or absence of the bulging of all the bolts. In the above examples, the object to be fastened is an electric wire for high power, but the present invention is not limited to this, and is effective when used for fastening parts of important safety parts of vehicles such as railway vehicles and automobiles. Of course. If the soft material 14 is mixed with a substance that discolors or is colored when deformed, for example, a pressure-sensitive substance, it is possible to further facilitate visual discovery.

[0011]

As described above, according to the present invention, the soft material 14 interposed between the screw fastening tool S such as the bolt 11 and the nut 12 and the article 10 to be fastened receives a fastening force. Since the appearance will change depending on whether it is not, visually deciding whether or not the screw fastener S is tightened, instead of the conventional work of checking each bolt with a wrench. You can Therefore, it becomes extremely easy to inspect whether or not the screw is forgotten to be tightened, and it is possible to avoid forgetting to tighten the screw. Further, since the means is simple, only the small protrusion is provided on the fastening portion, there is an effect that the implementation is easy and the cost is low for implementation.

[Brief description of drawings]

FIG. 1 is an external view of high-voltage electric wiring showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a II-II cross section before fastening.

FIG. 3 is a cross-sectional view showing a cross section corresponding to FIG. 2 after fastening.

FIG. 4 is a front view of a washer that is a main part of FIG.

FIG. 5 is a sectional view thereof.

FIG. 6 is a front view of a washer corresponding to FIG. 4 showing another embodiment.

FIG. 7 is a sectional view thereof.

FIG. 8 is a front view of a washer corresponding to FIG. 4 showing another embodiment.

FIG. 9 is a sectional view thereof.

[Explanation of symbols]

 10 Conductive Band 11 Bolt 12 Nut 20 Washer 14 Soft Material

Claims (3)

[Claims] 1. A relative surface formed by a fastener and an object to be fastened to one of a screw fastener including a bolt, a nut or a washer and an object to be fastened by the screw fastener. A through hole that opens in the axial direction is provided, and a soft material is arranged in the vicinity of the through hole, and when the relative surface is pressed, the soft member swells into the opening, and the presence or absence of the swelling is checked. A method to prevent screws from being forgotten by visually observing whether or not they have been forgotten. 2. The soft material according to claim 1, wherein the soft material is made of a material that discolors when a predetermined stress is applied, and after the screw fastener is tightened, the presence or absence of the discoloration is visually checked. The method to prevent forgetting to tighten the screw that makes it easy to determine whether or not it has been deformed. 3. The screw fastening according to claim 1, wherein the soft material is made of a material that discolors when heat is applied, and when the screw fastening tool is used to fasten electric wiring, the soft fastening is forgotten. A method for preventing forgetting to tighten a screw, which makes it easy to determine whether or not the soft material has been deformed by visually observing the presence or absence of discoloration caused by the heat generation of the tool.