JP2003048171A - Tightening error prevention method for screw part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tightening error prevention method for a screw part limiting the screw part to be tightened per exclusive tool. SOLUTION: At least one recessed part 3 or more are provided on a side face of an engaging part of the screw part with a socket. On the other hand, a projection 4 corresponding to the recessed part 3 is provided on an inner face of a socket of the exclusive tool. This exclusive tool cannot tighten the ordinary screw part because the projection 4 becomes an obstacle and can specify the screw part capable of being tightened. Moreover, this exclusive tool can be used as an exclusive tool capable of managing tightening torque.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing a wrong screw component tightening which is effective when tightening a plurality of screw components such as bolts and nuts with a plurality of dedicated tools whose tightening torque is controlled. .

[0002]

2. Description of the Related Art For example, in an automobile assembly line or the like, it is often required to fasten bolts with different torques, and a plurality of types of dedicated tools in which the tightening torques are controlled for each fastening portion are used.
However, the socket of each dedicated tool can be fitted to any bolt as long as the size of the bolt is the same, so it is possible to accidentally tighten another type of bolt. There is a risk that the bolts may be tightened incorrectly and this may result in a poor ground.

[0003]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, limits the screw parts that can be tightened for each dedicated tool, and prevents screw parts of the wrong type from being tightened. The purpose of the invention is to provide a method for preventing a screw component from being mistakenly tightened.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, a method for preventing a mistake in tightening a screw part of the present invention is provided with at least one recess on the side surface of the engaging part of the screw part with a socket. By providing a protrusion corresponding to the recess on the inner surface of the socket of the dedicated tool for tightening the screw component, the screw component that can be tightened by the dedicated tool is specified.

According to the present invention, since the projection is provided on the inner surface of the socket of the dedicated tool, only screw parts such as bolts and nuts having recesses into which the projection can be properly inserted can be tightened. For this reason, it is possible to prevent a problem caused by erroneous product tightening without accidentally tightening an ordinary screw part or another type of screw part.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in more detail with reference to the drawings. FIG. 1 is a view showing an example of a head shape of a bolt 1 used in the present invention, in which a recess 3 is formed on each side surface of a hexagonal head 2. In this embodiment, the recess 3 has a semicircular cross section and a width of 6
Although it is about 1/3 of one side of the angular diameter, it is not necessarily limited to this shape. However, since the strength of the head 2 of the bolt 1 gradually decreases as the width of the recess 3 increases, it is not preferable to make the recess 3 too large.
However, the depth of the recess 3 is preferably 0.5 mm or more.

On the other hand, FIG. 2 is a sectional view showing the shape of a socket 4 of a special tool for tightening the bolt 1 of FIG. 1, in which the above-mentioned bolt 1 is formed on the inner surface of the hexagonal socket 4.
A projection 5 having a semicircular cross section is formed so as to correspond to the concave portion. In this embodiment, the protrusions 5 of the socket 4 are formed on two opposite sides, but they may be formed on all six sides.

When the bolt 1 of FIG. 1 is tightened by using a dedicated tool having such a socket 4, the projection 5 on the inner surface of the socket 4 fits into the recess 3 of the head 2 as shown in FIG. Therefore, it is possible to tighten the bolts in the same manner as when tightening a normal bolt with a normal dedicated tool. However, even if an ordinary bolt is tightened by using this special tool, the protrusion 5 on the inner surface of the socket 4 as shown in FIG.
Interferes with the head of the bolt and the head of the bolt does not go into the socket. For this reason, it is immediately known that the bolt is not correct, and it is possible to prevent erroneous tightening. The bolt can be tightened and removed by using a normal socket having no protrusion 5 on the inner surface.

In the above example, since the recess 3 is formed on each side surface of the head 2 of the bolt 1, the socket 4 can be fitted into the head 2 from any angle, which is advantageous in workability. However, as shown in FIG. 5, if the concave portion 3 is formed only on a specific side of the bolt 1 and the protrusion 5 is formed corresponding to the socket of the special tool, the special tool and the bolt 1 are locked. It will correspond more closely like a key and the bolt 1 that can be tightened by the dedicated tool can be specified more strictly.

The present invention is not limited to bolts and nuts,
It is obvious that it can be directly applied to screw parts such as tapping screws and machine screws. Further, the present invention is not limited to hexagonal threaded components, but can be applied to deformed threaded components such as pentagons and dodecagons.

[0011]

As described above, according to the method for preventing screwing error of the screw part of the present invention, by providing the protrusion on the inner surface of the socket of the special tool, the screw part that can be tightened by the special tool. Can be specified.
For this reason, it is possible to prevent the mistake of tightening other screw parts by mistake. In particular, the present invention is a method suitable for correctly associating the dedicated tool with the screw part to be tightened when the set torque of the dedicated tool is different.

[Brief description of drawings]

FIG. 1 is a plan view showing a head shape of a bolt.

FIG. 2 is a sectional view showing a socket of a dedicated tool.

FIG. 3 is a cross-sectional view showing a fitted state.

FIG. 4 is a cross-sectional view showing an interference state.

FIG. 5 is a cross-sectional view showing another embodiment.

[Explanation of symbols]

1 volt 2 heads 3 recess 4 Dedicated tool socket 5 protrusions

Continued front page    (72) Inventor Ryoho Tsubogi             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd.

Claims (2)

[Claims] 1. At least one recess is provided on a side surface of an engaging portion of a threaded component with a socket, and a projection corresponding to the recess is provided on an inner surface of a socket of a dedicated tool for tightening the screw component. A method for preventing screw component tightening errors, characterized by identifying screw components that can be tightened by a dedicated tool. 2. The method for preventing wrong tightening of screw parts according to claim 1, wherein the special tool is a special tool whose tightening torque is controlled.