JPH081542A - Drive screw device - Google Patents

Abstract

PURPOSE:To eliminate idle rotation of a bit by forming a separate groove to correspond to a forward end form of the bit in a bit receiving groove in a screw head part of a drive screw by drive action of the bit. CONSTITUTION:In a drive screw device for threading a drive screw 2 into a material by rotating a bit after striking the drive screw 2 by the bit 1 driven from an impact tool, the bit 1 has a forward end of a cross sectional form of a polygon, height of the drive screw 2 is set to be smaller than that of the bit 1, and a bit receiving groove 4 is formed in an upper surface of a screw head part 2b to be different from a forward end form of the bit 1. A size w1 of an aperture end of the bit receiving groove 4 is set to be larger than the maximum width 2 of the forward end of the bit 1, so when the bit 1 strikes the drive screw 2, the forward end form of the bit 1 is grooved in the receiving groove 4 of the screw head part 2b. Threading can thus be performed securely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving screw device composed of a driving screw and a bit for driving the driving screw.

[0002]

[Prior art and its problems] The driving screw is Japanese Patent Publication No. 59.
As shown in FIG. 1 of Japanese Unexamined Patent Publication No. 39607, a shaft portion is formed of a screw portion and a shell-shaped tip portion, and is used, for example, when fixing wood, gypsum board, etc. to a steel plate base material,
After hitting the head of the screw with a bit of an impact tool to penetrate the steel plate, it is further rotated and screwed into wood or gypsum board to fix and bond the above materials.
The screw is rotated by fitting the tip of the bit into the groove of the screw head (formed in a cross shape, etc.), but the tip of the bit matches the groove of the screw head when hit. It is not always like that.

If the tip of the bit is driven in a state where it does not match the groove of the screw head, the groove of the screw head is deformed and damaged,
Since the engagement with the bit is not performed properly, the driving screw does not follow the rotation of the bit at the time of screwing after the impact, and the bit may idle and a tightening failure may occur.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks and to provide a driving screw device in which the tip of a bit is engraved on the screw head at the time of impact so that the screw head can always be reliably screwed. To that end.

[0005]

In order to achieve the above-mentioned object, a driving screw device according to the present invention is configured such that, after a driving screw is struck by a bit punched from an impact tool, the driving screw is rotated to remove the driving screw. In a driving screw device for screwing into a material, the cross-sectional shape of the tip of the bit is polygonal, the hardness of the driving screw is smaller than that of the bit, and the top surface of the screw head is different from the tip shape of the bit. A bit receiving groove is formed, the opening end of this bit receiving groove is made larger than the maximum width of the tip of the bit, and when the above bit hits the driving screw, the tip shape of the bit is engraved in the receiving groove of the screw head. It is characterized by doing.

[0006]

The action and effect of the present invention: After setting the driving screw under the bit, the tool is operated to drive the bit, and the bit hits the screw head of the driving screw. The tip of the driving screw is driven into the material, but at the same time, the open end of the bit receiving groove is formed larger than the maximum width of the bit tip, so the tip of the bit collides with the inner surface of the bit receiving groove of the screw head. To do. Further, since the hardness of the driving screw is smaller than the hardness of the bit, the corners of the tip of the bit bite into the inner surface of the bit receiving groove to engrave the tip shape of the bit. As a result, another triangular receiving groove corresponding to the tip shape of the bit is formed in the screw receiving groove. Then, when the bit is rotated, the driving screw rotates following the rotation of the bit and is screwed into the material.

As described above, by the driving operation of the bit, another receiving groove corresponding to the tip shape of the bit is formed in the bit receiving groove of the screw head of the driving screw. Since the other receiving groove matches the tip shape of the bit and meshes with the bit, the rotation is accurately transmitted to the driving screw when the bit is rotated. Therefore, no matter which direction the tip of the bit is driven into the bit receiving groove of the driving screw, the bit does not run idle and the driving screw can always be screwed in reliably.

[0008]

1 is a front view of a driving screw device according to the present invention, and FIG. 2 is an enlarged sectional view of a screw head.

In each of the above drawings, reference numeral 1 is a bit, and 2 is a driving screw.

The bit 1 is driven by a striking mechanism of an impact tool (not shown) and then rotated by a rotary drive mechanism, and its tip 1a has a triangular cross section as shown in FIG. The driving speed at the time of hitting the bit 1 is usually 10 to 20 m / s.

The driving screw 2 is composed of a screw shaft portion 2a and a screw head portion 2b. The screw shaft portion 2a is formed with a screw portion 3 and its tip portion 5 is formed into a substantially bullet shape. .

A bit receiving groove 4 is formed on the upper surface of the screw head 2b. The inner surface of the bit receiving groove 4 is simply formed in a concave shape, which is different from the tip shape of the bit 1.
The dimension w1 of the opening end of the bit receiving groove 4 is formed larger than the maximum width w2 of the tip of the bit 1.

Next, the hardness of the driving screw 2 is set smaller than that of the bit 1. The hardness of the driving screw 2 is a Vickers hardness of HRC20 to 45 (JIS B11
25), the hardness of bit 1 is HRC53 or higher (JIS B
4633).

According to the above construction, after setting the driving screw 2 below the bit 1, the impact tool is operated to drive the bit 1 so that the bit 1 drives the driving screw 2.
The screw head 2b is hit. The tip of the driving screw 2 is driven into the material, but at the same time, since the opening end of the bit receiving groove 4 is formed to be larger than the maximum width of the tip of the bit 1, the tip of the bit 1 receives the bit receiving portion of the screw head 2b. Groove 4
Collide with the inner surface of. Further, since the hardness of the driving screw 2 is smaller than the hardness of the bit 1, as shown in FIG.
The corners of the tip of the bit bite into the inner surface of the bit receiving groove 4 to engrave the tip shape of the bit 1. As a result, another triangular receiving groove (second receiving groove 4a) corresponding to the tip shape of the bit 1 is formed in the screw receiving groove.

Next, when the bit 1 is rotated while the tip of the bit 1 is biting into the second receiving groove 4a by the driving operation, the driving screw 2 rotates following the rotation of the bit 1, Screwed into the material.

As described above, by the driving operation of the bit 1, the bit receiving groove 4 of the screw head 2b of the driving screw 2 is formed.
A second receiving groove 4a corresponding to the shape of the tip of the bit 1 is formed therein. Since the second receiving groove 4a naturally matches the tip shape of the bit 1, the second receiving groove 4a is in mesh with the bit 1, and when the bit 1 is rotated, its rotation is driven by a driving screw. 2 is transmitted accurately. Therefore, no matter which direction the tip of the bit 1 is driven into the bit receiving groove 4 of the driving screw 2, the bit 1 does not idle, and the driving screw 2 can always be screwed in reliably.

The shape of the tip 1a of the bit 1 is not limited to a triangle. It may be a quadrangle as shown in FIG. 4 or another polygon, or may be a cross or the like.

The receiving groove 4 of the bit 1 is not limited to the concave shape. For example, it may be conical or the like as shown in FIG.

[Brief description of drawings]

FIG. 1 is a front view of a driving screw device according to the present invention.

FIG. 2 is a perspective view of the tip of the bit.

FIG. 3 is an enlarged cross-sectional view of a state in which a bit is driven into a screw head of a driving screw.

FIG. 4 is a bottom view of another example of the tip shape of the bit.

FIG. 5 is an enlarged cross-sectional view of a bit receiving groove of the driving screw.

[Explanation of symbols]

 1 bit 2 driven screw 2b screw head 4 bit receiving groove

Front page continuation (72) Inventor Yoshio Fukushima 6-6 Hakozakicho, Nihonbashi, Chuo-ku, Tokyo Max Co., Ltd.

Claims (1)

[Claims] 1. In a driving screw device in which a driving screw is struck by a bit driven from an impact tool, and then the driving screw is rotated into the material to screw the driving screw into a material, the cross-sectional shape of the tip of the bit is polygonal. In addition, the hardness of the driving screw is smaller than that of the bit, and a bit receiving groove that is different from the tip shape of the bit is formed on the upper surface of the screw head. A driving screw device which is made larger than the above, and when the bit hits the driving screw, the tip shape of the bit is engraved in the receiving groove of the screw head.