JP2001289223A - Wood screw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wood screw capable of reducing screwing torque while preventing the formation of a crack in a wood part when screwed. SOLUTION: In this wood screw 1 with a head 3 formed at the base end and with a thread part formed at the tip, a tip part 2 of the thread part is formed into a spoon shape, and an opening of a thread groove 4a is connected to the base end of a face 2A corresponding to a spoon-shaped rake face so that the thread groove 4a of the wood screw is opened to the face 2A corresponding to the rake face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood screw for screwing to a wood part, and more particularly to a wood screw suitable for a hard wood part or a fragile wood part.

[0002]

2. Description of the Related Art Conventionally, when a wooden part is fastened to each other or when a metal or the like in which a mounting hole is previously drilled is attached to a wooden part, a so-called wooden screw is used. Is used.

[0003] In this kind of work such as fastening of wooden parts, when a wooden screw is screwed, particularly when a large diameter portion of the wooden screw enters, the wooden part often breaks due to the screwing. In particular, a hard wood part or a dry wood part is very fragile. In such a case, a pilot hole is drilled in advance in the wood part into which the wood screw is to be screwed, and then it is time-consuming to screw the wood screw. Work is forced.

[0004] However, when the number of wood screws to be attached is small, there is no problem, but when the number of wood screws is large, for example, when the sidewalk is formed by laying wooden blocks. When these blocks are fixed with wood screws, a great deal of work is required in combination with the rigidity of the xylem.

In recent years, in view of such a current situation, there is a type in which a slit is formed at a tip of a wood screw, or a type in which a cutting blade is formed at a tip, and these are slightly more in comparison with conventional ones. It was not a wood screw that could prevent cracking of the fundamental xylem to the extent that cracking was reduced.

The present invention has been made in view of such a situation, and it is possible to prevent a wooden part from cracking when screwed in as much as possible, and it is possible to screw a hard tree with a smaller torque. It is intended to provide such a wood screw.

[0007]

A wood screw according to the first aspect of the present invention is a wood screw having a head portion at a base end and a screw portion at a tip end thereof, and a tip portion ( A tip portion is formed in a spoon shape, and an opening of a screw groove is connected to a base end of a surface corresponding to the scooping surface so that a screw groove of a wood screw is opened in a surface corresponding to the spoon-shaped scooping surface. It is characterized by being.

However, according to the wood screw having such a configuration, the tip portion of the screw portion is formed in a spoon-like shape. In the part, the remaining portion of the spoon-shaped part becomes a space capable of accommodating the wooden part, and a part of the wood chips generated by drilling at the spoon-shaped tip part is discharged to the outside through the thread groove. Therefore, even if you screw in a wood screw,
The xylem is not cracked as much as possible. Further, as described above, the wood chips are effectively discharged to the outside, and the wood screws are not forcibly screwed in as in the related art, so that the wood chips can be screwed in with a small rotation torque.

The wood screw according to the second aspect of the present invention is a flathead screw having a head at a base end and a screw portion at a tip end thereof, wherein a screw is provided between the head and the screw portion. A reaming portion for reaming a portion protruding from the inner wall of the hole formed in the wooden portion.

However, according to the wood screw configured as described above, since the hole diameter is increased by the reaming process, even when the dish-shaped portion of the head is screwed into the wood portion, it is possible to use the wood screw as much as possible. The xylem does not break.

Further, in the wood screw according to the second aspect of the present invention, the reaming portion is formed adjacent to the tip side of the dish-shaped portion in side view of the head, and the reaming portion is formed. If the outer diameter of the head is configured to be smaller than the maximum diameter of the head and larger than the maximum diameter of the thread part,
Further, it is possible to effectively prevent the xylem from breaking.

The wood screw according to the third aspect of the present invention is a wood screw having a head portion at a base end and a screw portion at a tip end thereof, and a tip portion (tip portion) of the screw portion at the tip end. It is formed in a spoon shape, and a reaming portion is formed between the head and the screw portion.

However, according to the wood screw configured as described above, since the tip of the screw portion is formed in a spoon shape, drilling is performed when drilling the wood portion. At the tip, the remaining part of the spoon becomes a space for accommodating the wooden part, and some of the wood chips generated by drilling at the spoon-shaped tip is discharged through the thread groove. Therefore, even if a wooden screw is screwed in, the wooden part will not be broken as much as possible, and since the hole diameter has been increased by reaming processing, when the dish-shaped part of the head is screwed into the wooden part Also, the xylem is not broken as much as possible. Therefore, according to the wood screw having such a configuration, the wood screw has a very effective configuration for preventing cracking of the xylem.

Further, in the wood screw according to the first to third aspects of the present invention, if the wood screw is made of a high-strength stainless steel represented by stainless steel of the steel type name "ASL503", the torsion strength is extremely high. As a result, the diameter of the wood screw can be reduced, and the wood screw has a structure with less cracks in the wood.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a wood screw according to an embodiment (example) of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a side view of a wood screw according to this embodiment.
FIG. 2 shows the configuration of the tip of the wood screw shown in FIG.
3 is a partial arrow view, and FIG. 3 is a III-III arrow view of FIG. 1 showing a driver bit insertion hole in the head.

In FIG. 1, reference numeral 1 denotes a flat wood screw, and the wood screw 1 has a spoon-shaped tip 2 (see FIG. 2).
And a head 3 (see FIG. 3) having a dish-like (trapezoidal) side view at the base end. A screw part 4 is provided on the base end side of the spoon-shaped tip part 2.
Is provided. That is, the tip of the screw 4 on the tip side is formed in a spoon shape. The screw portion 4 has a screw groove 4a.
Is connected to a surface 2A corresponding to the spoon-shaped scooping surface of the spoon-shaped tip portion 2. Then, between the screw portion 4 and the head 3, to be precise,
A reaming portion 5 is formed adjacent to the distal end of the head 3. Then, the reaming portion 5 and the screw portion 4
A straight column 6 is formed between the two.

By the way, the above-mentioned tip portion 2 is shown in FIGS.
As shown in the figure, the shape is formed into a spoon shape, in other words, a shape like a shell-like shape vertically divided in half. In other words, it is formed in a shape such that a “spoon” is just attached to the tip of the wood screw 1, and the portion serving as the surface 2A corresponding to the spoon-shaped scooping surface becomes a flat surface in this embodiment. As shown in the figure, the tip of the screw groove 4a of the screw portion 4 is open on this flat surface. As shown in FIG. 2, the base end portion 2a of the flat surface 2A is formed in a lounge shape, and is smoothly connected to the distal end of the screw groove 4a.
It is configured such that wood chips cut on the surface 2A serving as a scooping surface can be smoothly sent to the screw groove 4a side. The screw portion 4 presses and presses the screw groove 4a like a normal wood screw.
The formation of the thread 4b swells to form the thread groove 4a and the thread 4b. That is, before forming the screw portion 4, the material diameter is substantially the same as the diameter of the cylindrical portion 6. Further, the reaming section 5
The blade body 5a for reaming is protruded from the inner wall of the screw hole formed by the screw portion 4, that is, the reaming process is performed so as to ream the protruding portion on the wooden portion that comes into contact with the screw groove 4a of the screw portion 4. It is formed in a spiral shape. This blade 5
a is formed on a top 5c having a triangular cross section,
The surface 5d in the rotation direction at the time of screwing in is configured to be a scooping surface for reaming.

In this embodiment (example), the edge 2e of the spoon-shaped tip portion 2 and the edge of the surface 5d of the reaming portion 5 are intentionally illustrated when rolling. A so-called “burr” that is not formed may be formed, and this configuration can further improve the machinability. However, even if there is no "burr", the above-described configuration provides the basic operation and effect of the present invention.

The outer diameter Dr of the reaming portion 5
Is smaller than the maximum diameter Dh of the head 3 and larger than the maximum diameter Dd of the screw portion 4. The diameter Ds of the column 6 is smaller than the maximum diameter Dd of the screw 4.

The wood screw 1 according to this embodiment is
As the material, a martensitic special stainless steel manufactured by Hitachi Metals, Ltd. and called "ASL503" (trade name) is used. This "ASL503" (trade name) has a torsional strength about 1.7 times that of a normal wood screw made of carbon steel for forging, so that the screw diameter of the wood screw can be reduced by one rank. That is, conventionally, 5 mm
The equivalent of a wood screw is 4m
A wood screw having a diameter of m is sufficient in strength. Therefore,
Since the diameter of the wood screw can be reduced, also in this regard, in combination with the above-described other configurations, the configuration is such that splitting of the wooden portion can be prevented in use.

According to the wooden screw according to the present invention thus configured, when used for fastening wooden parts, the wooden screw is screwed in as follows, and in this case, cracking of the wooden part can be prevented. That is, when screwed into the wooden part, the wooden part is pierced by the spoon-shaped tip part 2 at the tip. At this time, since the spoon-shaped tip part 2 is spoon-shaped, Only half the space occupied in the wooden portion is required, and the wood chips drilled at the distal end portion 2 are smoothly sent from the surface 2A corresponding to the spoon-shaped scooping surface to the base end side thread groove 4a side, It is discharged outside. Accordingly, in the process of screwing the tip 2, the volume of the wood screw 1 pushing the wood to the outer diameter decreases, so that the wood can be prevented from cracking. Then, the screwing further proceeds, and the dish-shaped portion of the head 3 of the wood screw 1 is screwed.
The portion protruding from the inner wall of the hole drilled in step (1) is reamed to increase the inner diameter of the hole, so that even if the dish-shaped portion of the head is screwed in, the wood does not crack. When a high-strength stainless steel represented by the above-mentioned “ASL503” (trade name) is used, the wood screw 1
Can be made one rank smaller than the diameter of a conventional wood screw, so that cracks in the wood can be further prevented.
Furthermore, as described above, in the case of this wood screw, wood chips generated when the wood screw 1 is screwed are effectively and smoothly sent to the base end side, so that the wood screw 1 can be screwed in with an extremely small torque. It becomes possible. Therefore, workability is also improved.

The drill bit hole 3F formed in the upper end surface of the head 3 of the wood screw 1 can be a cross hole like a general wood screw, but a "square bit" having a square shape in plan view. A hole for a bit having a rectangular cross section (refer to FIG. 4) called a wood screw for a hard wooden part, in that the bit hole does not collapse,
This is a preferable configuration in that high torque can be transmitted.

By the way, in the above-described embodiment, a wood screw having a spoon-shaped distal end portion and a reamed portion formed near the proximal end portion has been described. Even with a wood screw having only one of the two structures, the wood screw is much less cracked than a conventional wood screw. In addition, even if the same material as the conventional wood screw is used, it goes without saying that the wood screw is less likely to be cracked than the conventional wood screw.

As for the specific shape of the spoon-shaped tip at the above-mentioned point, the surface 2A corresponding to the scooping surface is a flat surface as shown in FIG. 1 or FIG. However, it may be a concave surface.

Further, in terms of material, the steel type name "A
SL503 ”is not limited to stainless steel,
Even if it is the same kind of stainless steel provided by a plurality of steel manufacturers, or even other non-stainless steel, as long as the material has a high torsional strength,
It has the same function and effect resulting from the fact that the screw diameter can be reduced. However, the stainless steel of the above-mentioned steel type name “ASL503” is a suitable material when used outdoors exposed to acid rain or the like because it has excellent properties in terms of corrosion resistance.

[0027]

According to the wood screw according to the present invention, even when the wood screw is screwed into a hard wood part as compared with the conventional wood screw, the wood screw can be used.
Cracking does not occur, and it is possible to screw in with lower torque than before.

[Brief description of the drawings]

FIG. 1 is a side view of a wood screw according to the present embodiment.

FIG. 2 is a view showing a configuration of a tip portion of the wood screw shown in FIG. 1;
FIG. 2 is a view taken along the line II-II of FIG.

FIG. 3 is a view showing an insertion hole of a driver bit on a head.
FIG. 3 is a view taken in the direction of arrows III-III.

FIG. 4 is a diagram illustrating an insertion hole for a driver bit on a head according to a different form from FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... wood screw 2 ... tip part 2A ... surface equivalent to a scooping surface 3 ... head 4 ... screw part 4a ... screw groove 5 ... reaming processing part

Claims (5)

[Claims] 1. A wood screw having a head at a base end and a screw portion at a tip end thereof, wherein a tip portion of the screw portion is formed in a spoon shape,
A wood screw, characterized in that a screw groove opening is connected to a base end of a surface corresponding to the scooping surface such that a screw groove of the wood screw opens in a surface corresponding to the spoon-shaped scooping surface. 2. A flathead screw having a head at a base end and a screw portion at a distal end thereof, wherein a screw is formed between the head and the screw portion from an inner wall of a hole formed in the wood portion with a screw portion. A wood screw, wherein a reamed portion for reaming a protruding portion is formed. 3. The reaming portion is formed adjacent to the tip of a dish-shaped portion in a side view of the head, and the outer diameter of the reaming portion is the maximum diameter of the head. 3. The wood screw according to claim 2, wherein the diameter is smaller than the maximum diameter of the screw portion. 4. A wood screw having a head at a base end and a screw portion at a tip end thereof, wherein a tip portion of the screw portion is formed in a spoon shape, and the head and the screw portion are formed. A wood screw, wherein a reaming portion is formed between the screw. 5. The wood screw has a steel type name “ASL503”.
The wood screw according to any one of claims 1 to 4, wherein the wood screw is made of high-strength stainless steel typified by stainless steel.