JPH0741930Y2 - Self-threading screw - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-screw screw such as a tapping screw or a drill screw, and more particularly to a structure of a head provided on the upper end of a shaft.

[0002]

2. Description of the Related Art In the field of construction, for example, tapping screws and perforating screws are used to fix an attachment such as a panel to an adherend. The former tapping screw is used for a prepared hole previously provided in the adherend. Self-screw while tapping, and the latter screw is a screw that self-drills with respect to an adherend having no prepared hole.

When the head of the self-threading screw as described above is made of metal, the head having a simple metallic color is exposed as it is on the surface of the attachment, and the head does not match the color tone of the attachment. There is a disadvantage that aesthetic appearance is impaired and rust is generated over time. Therefore, a self-screw screw in which a metal head is covered with a synthetic resin head has been proposed.

The conventional self-threading screw 1 described above is shown in FIG.
As shown in (A), at the upper end of the shaft portion 2 that is self-screwed,
A circular collar 3 and a hexagonal metal head 4 are integrally provided on the upper surface of the collar 3, and a driver engagement groove 5 is formed on the upper surface of the metal head 4.
And the outer surface of the collar 3 is covered with a hexagonal head 6 made of synthetic resin.

A large rotational torque is required to screw the self-threading screw 1 into the adherend. Generally, a socket wrench mounted on a power tool driven by electric power or air is used as a hexagon head. 6 is externally fitted and engaged, and in this state, the self-screw screw 1
The hexagonal head 6 is subjected to a large load by being rotated, and the load is maximized when the screwing into the adherend is completed.

[0006]

By the way, the metal head 4 in the conventional self-threading screw 1 is formed in a flat hexagonal shape as shown in FIG. 3B, and the hexagonal head is made of synthetic resin. Since the portion 6 is formed on the outer circumference of the metal head 4 so as to cover the metal head 4 by forming it into a hexagonal shape with a uniform thickness, the load of the socket wrench on the metal head 4 and the hexagonal head 6 is received. Both sides were flat.

For this reason, when the screw tightening is completed, a load is applied in the screwing direction by the socket wrench, and the hexagonal head 6 made of synthetic resin is compressed between the socket wrench and the metal head 4, especially, the hexagonal head. The force A is concentrated in the vicinity of the corners of the portion 6 as shown by the arrow in FIG. 3 (B), but since the metal head 4 has a flat peripheral surface, the load can be received on the flat surface. Therefore, the load acting on the hexagonal head 6 cannot be dispersed in the synthetic resin, and even if a synthetic resin having excellent physical properties is used, this causes the hexagonal head 6
There is a problem that breakage B occurs at the corners of the.

Therefore, an object of this invention is to provide a self-screw screw which is made of a synthetic resin and which can prevent the hexagonal head from being broken by improving the shape of the metal head.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention integrally provides a metal head having a substantially elliptical plane shape at the end of a shaft portion that self-screws. The metal head is covered with a synthetic resin polygonal head.

[0010]

[Function] Since the metal head is formed in a substantially elliptical shape, the outer peripheral surfaces of both ends located in the long axis direction are circular, and the load applied near the corners of the polygonal head made of synthetic resin at the time of tightening. , Can be dispersed in synthetic resin along the curved surface of the metal head,
This prevents breakage of the corners of the polygonal head.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. 1 and 2 of the accompanying drawings.

As shown in the figure, the self-screw screw 11 has a male screw 13 around the outer circumference of a shaft 12 which is self-screwed, and a drill portion 14 for drilling at the tip thereof.
At the upper end of the, large-diameter head 15 without screws, and this large-diameter head 1
5, a circular collar 16 and a metal head 17 having a substantially elliptical plane are sequentially provided integrally on the upper surface of the collar 16, and the metal head 27 and the collar 16 are integrally covered with a synthetic resin. It is being appreciated.

The synthetic resin that covers the collar 16 becomes a synthetic resin collar 18 that covers the outer peripheral surface and the upper surface from the lower surface of the collar 16, and
The portion covering the metal head 17 is formed into a hexagonal polygonal head 19, and the synthetic resin brim 18 and the polygonal head 19 are integrally formed by using a synthetic resin having excellent crush resistance and abrasion resistance. It is molded and colored to the desired color.

As shown in FIG. 1 (C), the polygonal head 19 made of synthetic resin with respect to the metal head 17 is arranged so that one diagonal line of the hexagon is aligned with the longitudinal direction of the metal head 17. The metal head 17 is formed by determining the phase, and the planar shape of the metal head 17 may be not only a perfect elliptical shape but also an oval shape.

As described above, the planar shape of the metal head 17 having the long axis and the short axis exhibits the function of preventing the synthetic resin polygonal head 19 from rotating with respect to the metal head 17.

In the illustrated case, the packing 20 is attached to the large-diameter shaft portion 15, and the self-threading screw 11 is a self-drilling screw having the drill portion 14. However, a male screw is provided up to the tip of the shaft portion. It may be a tapping screw.

The self-threading screw of the present invention is constructed as described above, and a polygonal head 19 made of a synthetic resin is engaged with a socket wrench and the self-threading screw 11 is rotated so that the self-threading screw can be attached to an adherend. Screw in.

At the time of screwing with a socket wrench, especially when screwing into the adherend is completed, a large force acts on the surface side of the hexagonal head 19 made of synthetic resin that rotates near each corner.

At this time, as shown in FIG. 1C, the thickness of the periphery of the polygonal head portion 19 is such that the corner portions located on the minor axis direction side of the metal head portion 17 are thicker. Has sufficient strength against load.

On the other hand, the vicinity of the corner located in the major axis direction is thinner than the other parts, but the metal head 1 is located at this corner.
Since the arcuate surface of No. 7 is located, as shown by an arrow in FIG.
It is possible to allow the force to escape along the arc-shaped surface of the polygonal head and to disperse this force in the synthetic resin forming the polygonal head 19, thereby preventing the polygonal head 19 from breaking.

[0021]

As described above, according to the present invention, since the metal head covered with the polygonal head made of synthetic resin is formed in a substantially elliptical plane shape, the screwing of the self-threading screw to the adherend is completed. At times, the force applied to the vicinity of the corners of the polygonal head can be dispersed in the synthetic resin of the polygonal head, and the occurrence of breakage of the polygonal head can be prevented.

[Brief description of drawings]

FIG. 1A is a front view of a self-screw screw according to the present invention, FIG. 1B is a vertical sectional front view of a main part of the same, and FIG. 1C is a cross-sectional plan view of the main part.

FIG. 2 is a perspective view showing a metal head of a self-threading screw.

3A is a vertical sectional front view showing a conventional self-threading screw, and FIG. 3B is a transverse plan view of the same.

[Explanation of symbols]

 11 Self-threading screw 12 Shaft part 13 Male screw 14 Drill part 16 Tsuba 17 Metal head 19 Polygonal head made of synthetic resin

Claims (1)

[Scope of utility model registration request] 1. A self-screwed shaft part is integrally provided with a metal head having a substantially elliptical planar shape, and the metal head is covered with a polygonal head made of synthetic resin. Screw screw.