JPH08270631A - Machine screw - Google Patents

Abstract

PURPOSE: To provide a machine screw whereby a mounted material of face material or the like, pressed by a machine screw head part, is prevented from swelling up to improve a finish. CONSTITUTION: In a machine screw provided with a drill bit part 4 coaxially further of diameter almost equal to a screw part 3 in its point end by providing a machine screw head part 2 in the base end to protrude an edge of the drill bit part 4 adjacent to the screw part 3 in an external diametric direction so as to form a protrusion part 4a which can come off, a tapered part 2a is provided around the screw part 3 in a reverse surface of the machine screw head part 2, to provide a plane part 2b orthogonal to an axial center direction in the periphery of the tapered part 2a in the reverse surface of the machine screw head part 2. When the machine screw head part 2 is sunk in a mounted material of face material or the like, the mounted material is compressed by the plane part 2b just thereunder, so that swelling up to the periphery of the machine screw head part 2 can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to screws.

[0002]

2. Description of the Related Art Conventionally, when a panel is manufactured, an inorganic or wood-based face material is attached to a frame made of channel steel by using screws. As shown in FIG. 7, the screw has a drill bit portion 51 at the tip of the screw portion 50 for penetrating the frame. Further, since a gap is provided between the face material and the screw portion 50 due to the difference in thermal expansion coefficient between the face material and the frame,
A protrusion 51 a is formed on the outer peripheral surface of the drill bit portion 51. During the assembling work, the protrusion 51a forms a hole having a diameter larger than the outer diameter of the threaded portion 50 in the face material, and then hits the frame and falls off, whereby the drill bit part 51 can penetrate the frame.

[0003]

However, when the face material is attached to the frame with the conventional screw as described above, the face material 55 is attached to the taper portion 52a provided on the back surface of the screw head 52 as shown in FIG. As a result of being pressed, swelling A occurs around the screw head 52. Therefore, the finish when the screw head 52 is putty-filled in a later step is poor, and the face material 5
There was a problem that the cosmetic material could not be adhered to the cosmetic material even when it was attached to the cosmetic material. Further, when a prepared hole is provided in the face material in advance, a screw having no protrusion is used, but the same problem occurs in this case as well.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a screw which can be finished well without the attached material such as a face material pressed against the screw head rising up around the screw head.

[0005]

The screws according to claim 1 are
It is characterized in that a taper portion is provided around the screw portion on the back surface of the screw head, and a flat surface portion orthogonal to the axial direction is provided on the outer periphery of the taper portion on the back surface of the screw head. The screw according to claim 2 is provided with a drill bit portion coaxial with the screw portion and having substantially the same diameter as the screw portion provided with a screw head portion at the base end, and is inserted into a prepared hole provided in the mounted material. A screw is provided, and a taper portion is provided around the screw portion on the back surface of the screw head,
The maximum outer diameter of the tapered portion is set to be equal to or smaller than the diameter of the pilot hole, and a flat portion orthogonal to the axial direction is provided on the outer periphery of the tapered portion on the back surface of the screw head. Is.

According to a third aspect of the present invention, there is provided a screw bit portion having a screw head portion at a base end, and a drill bit portion coaxial with the screw portion and having substantially the same diameter as that of the screw portion, and the drill adjacent to the screw portion. A screw having a protrusion that can be removed by protruding the blade of the bit portion in the outer diameter direction, wherein a taper portion is provided around the screw portion on the back surface of the screw head, and the back surface of the screw head is provided. A flat surface portion orthogonal to the axial direction is provided on the outer circumference of the taper portion.

[0007]

According to the structure of the first aspect, when the screw head sinks into the material to be attached such as a face material, the material to be attached is compressed by the flat surface portion just below the flat surface portion. Also, even if the attached material is pressed by the taper portion and tries to rise around it, since the flat portion is provided on the outer periphery of the taper portion, the flat portion compresses the rise directly below the flat portion, and the screw head It is possible to eliminate the excitement around the.

According to the second aspect of the present invention, the maximum outer diameter of the tapered portion is set to be equal to or smaller than the diameter of the prepared hole and the flat portion is provided on the outer periphery of the tapered portion. When the screw head sinks into the prepared hole of the mounted material by screwing it into a highly rigid member such as the lower frame, the tapered part smoothly enters the prepared hole, and the flat part allows the peripheral edge of the prepared hole to open. The part is compressed just below the flat part, and the swelling around the screw head can be eliminated.

According to the third aspect of the present invention, when the drill bit is screwed into the attached material such as a face material, the attached material is scraped by the protrusion of the drill bit portion, so that the protrusion rotates. A hole having the same diameter as the outer diameter of is provided. When the drill bit section is screwed in and the projection comes into contact with a member with high rigidity such as a frame, it will not enter any further.If screwed in this state, the projection will break and fall off, and the drill bit section and screw section You can enter.

When the screw head sinks into the material to be mounted, the peripheral edge portion of the opening of the hole is compressed by the flat surface portion just below the flat surface portion. Further, even if the attached material is pressed by the taper portion and tries to bulge around it, since the flat portion on the outer circumference of the taper portion is provided, the bulge is compressed directly below the flat portion by the flat portion, and the screw head It is possible to eliminate the excitement around the.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A screw according to a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the screw 1 is provided with a taper portion 2a and a flat portion 2b for reinforcement on the back surface of the screw head 2. Further, a drill bit portion 4 coaxial with the screw portion 3 and having substantially the same diameter is provided at the tip of the screw portion 3. The protrusion 4a is formed on the outer peripheral surface of the drill bit portion 4.
Is formed. That is, the protruding portion 4a is formed by protruding the blade of the drill bit portion 4 in the outer diameter direction, and is configured to break and drop when a load of a predetermined amount or more is applied.

A groove (not shown) is formed on the surface of the screw head 2 for engaging a tool such as a screwdriver, and the taper portion 2a is the back surface of the screw head 2 around the screw portion 3. It is provided in. Further, the flat surface portion 2b orthogonal to the axial direction is provided on the outer periphery of the taper portion 2a on the back surface of the screw head 2. In this case, assuming that the maximum outer diameter of the tapered portion 2a (inner diameter of the flat surface portion 2b) is A and the outer diameter of the circular locus around which the protruding portion 4a rotates is B, it is desirable to set A ≦ B. .

Using the screw 1 constructed as described above, as shown in FIG. 4, a panel 10 is manufactured by attaching an inorganic or wooden face material 11 to a frame 10 formed of channel steel or the like. That is, as shown in FIG. 2, the drill bit portion 4 at the tip of the screw 1 is screwed into the face material 11. At this time, since the face material 11 is scraped by the protrusion 4a of the drill bit portion 4,
A hole 12 having the same diameter as the outer diameter B of the circular locus about which the protrusion 4a, which is larger than the diameter of the screw portion 3, rotates is provided. As described above, the gap is provided between the screw portion 3 and the hole 12 by the face material 1
This is to prevent cracks or the like from being generated in the face material 11 due to the difference in the coefficient of thermal expansion between 1 and the frame 10.

When the drill bit portion 4 is screwed into the frame 10 and the protrusion 4a comes into contact with the frame 10, the drill bit portion 4 does not enter any further. If screwed further in this state, the protrusion 4a
Breaks and falls off, and as shown in Fig. 3, drill bit 4
Penetrates the frame 10 and the screw part 3 is screwed into the frame 10.
In this way, when the screw 1 penetrates the face material 11 and the frame 10 and the screw head 2 sinks into the face material 11, if A ≦ B, the tapered portion 2a smoothly enters the hole 12. And the surface material 11 near the opening of the hole 12 by the flat surface portion 2b
Is compressed just below the plane portion 2b. Therefore, the swelling of the screw head 2 around the head can be eliminated.

When A> B, the face material 11 near the opening of the hole 12 is pressed by the taper portion 2a and bulges around it, but the flat surface 2b on the outer periphery of the taper portion 2a raises the ridge. It can be compressed just below the flat surface portion 2b, and the swelling around the screw head portion 2 can be eliminated. In this embodiment, since the flat surface portion 2b is provided on the outer periphery of the taper portion 2a on the back surface of the screw head portion 2 as described above, the face material 11 and the screw head portion 2 do not rise around the screw head portion 2.
The surface of can be made flush. Therefore, the screw head 2
Even when the putty is filled into the
You can stick the cosmetic material in close contact with.

The second embodiment will be described with reference to FIGS. 5 and 6. In this embodiment, no protrusion is formed on the drill bit portion 24 of the screw 21. Therefore, the face material 11
In advance, a prepared hole 32 is drilled. In this case, assuming that the maximum outer diameter of the tapered portion 2a is A and the diameter of the prepared hole 32 is C,
It is set so that A ≦ C. Other configurations are the same as those of the first embodiment.

At the time of assembling work, as shown in FIG. 5, a pilot hole 32 is provided in the face material 11, a screw 21 is inserted into the pilot hole 32, and the drill bit portion 24 is screwed into the frame 10. As shown in FIG. 6, when the screw 21 penetrates the face material 11 and the frame 10 and the screw head 2 sinks into the face material 11, the tapered portion 2a smoothly enters the prepared hole 32 and is flat. Part 2b
By this, the face material 11 in the vicinity of the opening of the hole 32 is compressed right under the flat surface portion 2b, and the same effect as that of the first embodiment can be obtained.

If a prepared hole is formed in the frame 10 as well as the face material 11, a screw without a drill bit portion can be used.

[0019]

According to the screw of the first aspect of the invention, when the screw head sinks into the attached material such as a face material, the attached material is compressed by the flat portion directly below the flat portion. Also, even if the attached material is pressed by the taper portion and tries to rise around it,
Since the flat portion is provided on the outer circumference of the tapered portion, the flat portion compresses the bulge directly below the flat portion, and the bulge around the screw head can be eliminated. Therefore, when the putty is filled in the screw head in a later step, the finish is good, and the decorative material can be attached in a state of being in close contact with the attached material.

According to the screw of claim 2, since the maximum outer diameter of the tapered portion is set to be equal to or smaller than the diameter of the prepared hole and the flat portion is provided on the outer periphery of the tapered portion, the drill bit portion is attached to the material to be attached. When the screw head sinks into the prepared hole of the mounted material by screwing it into a highly rigid member such as the lower frame, the tapered part smoothly enters the prepared hole, and the flat part allows the peripheral edge of the prepared hole to open. The part is compressed just below the flat part, and the swelling around the screw head can be eliminated. Therefore, as in the first aspect, the finish is good when the putty is filled in the screw head.

According to the screw of the third aspect, when the drill bit is screwed into an attached material such as a face material, the attached material is scraped by the protrusion of the drill bit portion, so that the protrusion rotates. A hole having the same diameter as the outer diameter of is provided. When the drill bit section is screwed in and the projection comes into contact with a member with high rigidity such as a frame, it will not enter any further.If screwed in this state, the projection will break and fall off, and the drill bit section and screw section You can enter.

When the screw head sinks into the material to be mounted, the peripheral edge portion of the opening of the hole is compressed by the flat surface portion just below the flat surface portion. Further, even if the attached material is pressed by the taper portion and tries to bulge around the taper portion, since the flat portion on the outer periphery of the taper portion is provided, the bulge is compressed directly below the flat portion by the flat portion, and It is possible to eliminate the excitement around the. Therefore, as in the first aspect, the finish is good when the putty is filled in the screw head.

[Brief description of drawings]

FIG. 1 is a front view of a screw according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of an initial stage of attaching a face material to a frame by using this screw.

FIG. 3 is an explanatory view of the action of this screw in the latter stage of FIG.

FIG. 4 is a partially cutaway perspective view of a panel in which this screw is used.

FIG. 5 is an explanatory diagram of an initial stage of attaching the face material to the frame using the screw of the second embodiment.

6 is an explanatory view of the action of this screw in the latter stage of FIG.

FIG. 7 is a front view of a conventional screw.

FIG. 8 is an explanatory diagram showing a problem of the conventional example.

[Explanation of symbols]

 1 screw 2 screw head 2a taper portion 2b flat surface portion 3 screw portion 4 drill bit portion 4a protrusion portion

Claims (3)

[Claims] 1. A taper portion is provided around a screw portion on the back surface of the screw head, and a flat surface portion orthogonal to the axial direction is provided on the outer periphery of the taper portion on the back surface of the screw head. Screw. 2. A screw bit, which has a screw head at the base end, is provided with a drill bit portion coaxial with the screw portion and having substantially the same diameter as that of the screw portion, and the screw bit is inserted into a prepared hole provided in a material to be attached. There
A taper part is provided around the screw part on the back surface of the screw head, and the maximum outer diameter of this taper part is set to a dimension not larger than the diameter of the pilot hole. A screw characterized by having a plane portion orthogonal to the axial direction. 3. A drill bit portion coaxial with this screw portion and having substantially the same diameter is provided at the tip of a screw portion having a screw head at the base end, and a blade of the drill bit portion adjacent to the screw portion is removed. A screw formed with a protruding portion that can be projected in a radial direction and can be dropped, wherein a taper portion is provided around the screw portion on the back surface of the screw head, and the outer circumference of the taper portion on the back surface of the screw head. A screw characterized in that a flat portion orthogonal to the axial direction is provided on the.