JP2000297809A - Thin head screw - Google Patents

Abstract

(57) [Problem] To provide a screw having a small head thickness and a small nominal diameter without impairing the screwing function. A screw (1) comprising a head (2) having an engagement groove (5) with which a driver bit engages, and a leg (4) integrated with the head (2) and having a thread (3) formed therein. 5 is a thin headed screw 1 having a spherical surface formed with a large radius on the upper surface of the head 2, so that a screw used for a product having a relatively thin thickness can be obtained without impairing the function. Also, since the head is formed slightly spherical,
The heads do not adhere to each other during the heat treatment and the plating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the use of a screw head which is screwed into a work without projecting the head of the work from spoiling the aesthetic appearance of the work, and without causing any problem in the screw fastening function as a screw. Possible thin-headed screws.

[0002]

2. Description of the Related Art In recent electrical appliances and information equipment products, those which have been improved in performance and are relatively small in size are often used. Electronic devices such as electronic organizers, personal computers, and mobile phones have become widespread. Such products are required to be as light as possible and as thin as possible. At present, small screws having a nominal diameter of 2 mm or less are used for assembling the products. Therefore, in recent years, a screw having the smallest possible size has been developed. As shown in FIG.
Since the head 102 of No. 01 forms an engagement groove 105 to be engaged with the driver, the shape of the head 102 is still the same as before.

[0003]

However, despite the demand for such a thin product,
The inability to cope with the miniaturization of the product due to the limitation of miniaturization of the screw has had a great influence on future assembly work. To solve this problem, a screw whose head is thinner than a conventional screw with only a small nominal diameter has been considered, but a driver bit is attached to the head to make the head thinner by forging. Because of the presence of the mating engagement groove, the engagement groove becomes brittle and the engagement groove reaches the leg of the screw, so that the material of the leg is thinned or broken, and the function of the screw is not obtained. In addition, when heat treatment and plating are performed to give the necessary strength to the screw, if the top surface of the head is flat, the volume of the head is small, so that the heads adhere to each other during the processing operation. In such a case, there is a problem that the heat treatment and the plating process of the portion become incomplete.

[0004] An object of the present invention is to provide a screw which solves such a problem and which does not impair the screwing function even in a screw having a small head thickness and a small nominal diameter.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a head 2 having an engaging groove 5 with which a driver bit is engaged, and a leg united with the head 2 and having a thread 3 formed therein. 4 is a spherical shape formed with a large radius on the upper surface of a head 2 having an engagement groove 5 and a thickness of about 1/3 or less of a nominal diameter of the screw 1. This is achieved by providing a thin headed screw.

[0006]

FIG. 1 is a block diagram showing an embodiment of the present invention.
And FIG. In FIG. 1, 1 is a head 2
And a leg 4 integral with the head 2 and having a thread 3. The head 2 of the screw 1 has a cross-shaped engaging groove 5 for engaging with a driver bit (not shown) on the center line of the leg 4. 4 has been reached. The head 2 is formed to be relatively thinner than the head 2 of the ordinary screw 1. The thickness of the head 2 is set to about 1/3 or less of the nominal diameter of the screw 1. Have been. The upper surface of the head 2 has a spherical shape with a relatively large radius, and the outer peripheral edge of the head 2 is thinner than the thickness at the center.

The leg 4 at a position close to the seating surface 7 of the head 2 has a tapered reinforcing portion 10 on the head side larger than the thread outer diameter of the leg 4 and smaller on the thread side than the screw outer diameter. Is formed. The taper of the reinforcing part 10 has a predetermined thickness between the wall surface 6 of the engaging groove 5 and the angle of the taper is substantially equal to or slightly larger than the wall angle of the engaging groove 5. I have. The thread 3 is formed at the lower part of the reinforcing portion 10 so as to extend to the tip of the leg portion 4, and the reinforcing portion 10 is provided with an incomplete thread portion 11 of the thread 3. The incomplete threaded portion 11 is formed such that the root of the thread 3 is located on the extension of the taper of the reinforcing portion 10 or outside thereof, and the thread 3 is in contact with the wall surface 6 of the engagement groove 5. It is set so as to have a predetermined thickness between them.

In the operation of screwing into the work 20 using the thin-headed screw 1, as shown in FIG.
The driver bit is engaged with the engagement groove 5 of the screw 1 with respect to the prepared hole of the work 20 to transmit the screwing force and screw the screw.
At this time, the screwing force from the driver bit is
The screw 3 is screwed into the work 20 with a predetermined screwing force. Then, when the seating surface 7 of the head 2 is seated on the work 20, the screwing operation ends.

[0009]

As is apparent from the above-described embodiments, the present invention has a head 2 having an engaging groove 5 with which a driver bit engages, and a head 3 integral with the head 2 and having a thread 3
In the screw 1 composed of the leg 4 formed with
And a thin headed screw 1 having a spherical surface shape with a large radius formed on the upper surface of the head 2 whose thickness is set to about 1/3 or less of the nominal diameter of the screw 1. The screws used for relatively thin products can be obtained without impairing the original function of the screws.
In the future, it will be possible to assemble thin products using these screws. In addition, when heat treatment and plating are performed to give the necessary strength to the screws, the heads are slightly spherical, so that the heads adhere to each other during the heat treatment and plating. There is a unique effect that the surface treatment can be completely performed without unevenness.

[Brief description of the drawings]

FIG. 1 is a front view of a thin-headed screw showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a screwed state of the present invention.

FIG. 3 is a sectional view showing a screwed state of a conventional screw.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 screw 2 head 3 screw thread 4 leg 5 engagement groove 6 wall 7 seating surface 10 reinforcing part 11 imperfect screw part 20 work

Claims (2)

[Claims] 1. A head 2 having an engaging groove 5 with which a driver bit engages, and a screw thread 3 integrated with the head 2
A screw with a thin head, wherein the upper surface of the head 2 having the engaging groove 5 is formed in a spherical shape with a large radius. 2. The thickness of the head is 1 / th of the nominal diameter of the screw 1.
The thin-headed screw according to claim 1, wherein the dimension is set to about 3 or less.