【考案の詳細な説明】[Detailed explanation of the idea]
軽量気泡コンクリート板（ここで、軽量気泡コ
ンクリート板とは、JIS A5416に定義されるALC
を原料とする厚さ25〜75mmの成形板及び成形され
た気泡コンクリート板全てを指し、以下ALCボ
ードと略称する）は強度や断熱性に優れている
為、建物の外壁や野地板等に広く使用されてい
る。
しかし、ALCボードは吸水しやすい性質を持
つているため、素地のままでは外壁や野地板とし
ての使用は不適で、その表面に有効な防水処理が
不可欠である。そして、その防水の方法として、
外壁として用いる場合は、ALCボードを建築現
場に於いて別途手配される構造体に取付けた後
に、アクリル等高分子系の材料を砂壁状などにし
て吹き付ける方法が安価で一般的である。この砂
壁状吹付材などは非常に薄く、その下地はできる
だけ、均質でなければ所定の防水性能が得られな
い。
一方、ALCボードを木製の構造体（以下胴縁
という）に取り付け固定するための固定具として
釘を用いることが多いが、上記の表面均質度を確
保するため次の作業を行なつている。即ち、釘を
１度ALCボードの表面まで金槌で打ち込み、強
度の確保ができた後に更に釘締め等の道具を用い
て釘頭部をALCボードの内部へ衝撃力によつて
打ち沈め、ここで得られる穴部にパテ・モルタル
等ALCボードの材質に類似したものを充填して、
ALCボード表面の均質化を計つている。
このようにALCボードの固定具は、ボード内
部までその頭部を沈み込ませる事が必要で、釘は
その代表例であるが、作業上、非能率であり、省
力化できない。
作業能率を上げるために木ネジ（JIS Ｂ−
1135）を電動工具（例えば市販のスクリユードラ
イバー等）を用いて施工する事が考えられるが、
頭部を沈み込ませる要求点から不適である。理由
として、木ネジの頭部でALCボードを圧密しな
がらスクリユー部を胴縁内へネジ込んでいくが、
この過程で、ALCボードの圧密力が胴縁への木
ネジの推進力を上廻る事がある。この時胴縁内で
木ネジが空廻りして、木繊維のせん断破壊を起こ
し必要強度が得られない事があり、取付端力上危
険となる（木の材質、含水率の差などにより変化
する）。
結果的に頭部の沈み込みも得られない。実験に
て確認された各々の数値を表−１に示す。
Lightweight aerated concrete board (here, lightweight aerated concrete board is ALC defined in JIS A5416)
ALC board (hereinafter referred to as ALC board, which refers to all molded boards and molded aerated concrete boards with a thickness of 25 to 75 mm made from ALC) has excellent strength and heat insulation properties, so it is widely used for external walls of buildings, roof boards, etc. It is used. However, since ALC boards tend to absorb water, they are unsuitable for use as exterior walls or roofing boards in their raw form, so effective waterproofing treatment is essential for their surfaces. And as a method of waterproofing,
When used as an exterior wall, a cheap and common method is to attach the ALC board to a separately prepared structure at the construction site and then spray a polymeric material such as acrylic into a sand wall. This sand wall-like spray material is very thin, and the required waterproof performance cannot be achieved unless the base is as homogeneous as possible. On the other hand, nails are often used as fixing devices to attach and secure the ALC board to a wooden structure (hereinafter referred to as the frame), but the following work is performed to ensure the above-mentioned surface homogeneity. That is, once the nail is driven to the surface of the ALC board with a hammer, and after securing the strength, the head of the nail is driven into the inside of the ALC board by impact force using a tool such as a nail tightener, and then Fill the resulting hole with something similar to the material of the ALC board, such as putty or mortar.
We are trying to make the ALC board surface homogeneous. In this way, the fixing devices for ALC boards must have their heads sunk deep into the board, and nails are a typical example of this, but they are inefficient and cannot save labor. Wood screws (JIS B-
1135) using a power tool (such as a commercially available screwdriver),
It is unsuitable because it requires the head to sink. The reason is that the screw part is screwed into the body frame while compressing the ALC board with the head of the wood screw.
During this process, the compaction force of the ALC board may exceed the thrust of the wood screw into the barrel. At this time, the wood screws may spin loosely within the rim, causing shear failure of the wood fibers and not achieving the required strength, resulting in a dangerous installation end force (varies depending on wood material, moisture content, etc.). do). As a result, the head cannot sink. Table 1 shows each numerical value confirmed in the experiment.
【表】
註） 木の材質、含水率の変化による強度変
化を±25％として推定
本考案の木ネジは例えば、第１図に示すように
木ネジの頭部ａの一部にネジ頭周囲に連なる二辺
に長短差のあるコの字状の切り欠きｃを設け、さ
らにネジ軸ｄの径よりスクリユー部軸ｅの径を大
きくしたことを特徴とするものである。
本考案木ネジは頭部ａに二辺に長短差のあるコ
の字状の切り欠きｃを設け、さらにスクリユー部
軸ｅをネジ軸ｄより大きくしてあるので、本考案
の木ネジはALCボードの圧密力の軽減化が計れ、
これによつてALCボードの確実な強さが容易と
なる。即ち、第２図の施工例に示すように二辺に
長短差のあるコの字状の切り欠きｃである木ネジ
の頭部ａの回転により、木ネジ頭部裏面とALC
ボード１はよくこすれ合いALCボード１の局部
的な粉状化が改善される。そしてこの粉７の約70
％を木ネジ頭部ａの二辺に長短差のあるコの字状
の切り欠き部ｃから穴６に排出することができ
る。又、粉体７の約30％は木ネジ軸ｄとALCボ
ード１との間にできた細い隙間３に充填される。
このように二辺に長短差のあるコの字状の切り欠
きｃとネジ軸ｄ，ｅとの差から生じる隙間３とが
相俟つて従来の木ネジと比較するとALCボード
の圧密は軽減され、木製胴縁２への推進力を上廻
る事はない。
第１図における木ネジの頭部ａの二辺に長短差
のあるコの字状の切り欠きｃは、頭部面積の３％
以上が必要で、それ以下では効果は薄い。尚、そ
の数は１ケ所で充分である。
この切り欠きｃは非常に簡単に設けられるの
で、製造におけるコストアツプは微少であり、従
来の木ネジとほぼ同単価で提供できる。
また第１図Ａに示すように二辺に長短差のある
コの字状の切り欠きｃの底部からネジ軸ｄに向つ
ては傾斜を設けることがALCボードの粉状化物
の排出のために好ましい。
本考案の木ネジは、ALCボードの取付け上、
必要不可欠な固定具の頭部沈み込みを市販の電動
工具を用いて頭部ａのネジ廻し用穴ｂにあてがえ
ば、容易に、能率的に行う事ができ、固定具と胴
縁との強度保持とを割実に行う事ができる。又、
本考案の木ネジの使用例を外壁として用いる場合
を説明したが、ALCボードを野地板その他の用
途に用いる場合も全く同様の理由で含まれる。[Table] Note) Strength changes due to changes in wood material and moisture content are estimated as ±25%.For example, the wood screw of this invention has a screw head attached to a part of the head a of the wood screw, as shown in Figure 1. It is characterized in that a U-shaped notch c with a difference in length and length is provided on two continuous sides around the periphery, and the diameter of the screw shaft e is made larger than the diameter of the screw shaft d. The wood screw of the present invention has a U-shaped notch c with a length difference on two sides on the head a, and the screw axis e is larger than the screw axis d, so the wood screw of the present invention has an ALC. The consolidation force of the board can be reduced,
This facilitates reliable strength of the ALC board. In other words, as shown in the construction example in Figure 2, by rotating the head a of the wood screw, which is a U-shaped notch c with a length difference on two sides, the back side of the wood screw head and the ALC
The boards 1 rub against each other well, and local pulverization of the ALC board 1 is improved. And about 70 of this powder 7
% can be discharged into the hole 6 from a U-shaped notch c with a length difference on two sides of the wood screw head a. Also, about 30% of the powder 7 is filled into the narrow gap 3 formed between the wood screw shaft d and the ALC board 1.
In this way, the U-shaped notch c with the length difference on the two sides and the gap 3 created by the difference between the screw shafts d and e combine to reduce the consolidation of the ALC board compared to conventional wood screws. , does not exceed the propulsive force to the wooden trunk rim 2. In Figure 1, the U-shaped notch c with a difference in length on the two sides of the head a of the wood screw accounts for 3% of the head area.
More than that is necessary; anything less is less effective. Note that one location is sufficient. Since this notch c is very easily provided, the cost increase in manufacturing is minimal, and the screw can be provided at approximately the same unit price as a conventional wood screw. In addition, as shown in Figure 1A, it is recommended to provide an inclination from the bottom of the U-shaped cutout c with the length difference on the two sides toward the screw axis d in order to discharge the powdered substances from the ALC board. preferable. The wood screws of this invention are suitable for installing ALC boards.
If you use a commercially available electric tool to sink the head of the fixture into the screwdriver hole b of the head a, you can easily and efficiently sink the head of the fixture, which is essential. Strength can be maintained at a reasonable cost. or,
Although the example of using the wood screws of the present invention was explained as an exterior wall, the use of ALC boards for roofing boards and other purposes is also included for the same reason.
【図面の簡単な説明】[Brief explanation of the drawing]
第１図は本考案の木ネジ側面図Ａとその頭部平
面図Ｂ、第２図は胴縁にALC板を取付ける施工
例の縦断面図である。
１……軽量気泡コンクリート板（ALCボー
ド）、２……木製の胴縁、３……木ネジスクリユ
ーにより切削される穴の外周縁隙間、４……木ネ
ジ頭部、５……木ネジ頭部に設けられた切り欠き
部、６……木ネジ頭部により切削される軽量気泡
コンクリートの穴、７……木ネジ頭部の切り欠き
部より排出される粉状の軽量気泡コンクリート、
ａ……木ネジ頭部４、ｂ……ネジ廻し用穴、ｃ…
…頭部の切り欠き部５、ｄ……木ネジ軸の径、ｅ
……スクリユー部軸の径。
Fig. 1 is a side view A of the wood screw of the present invention and a plan view B of its head, and Fig. 2 is a longitudinal cross-sectional view of an example of installation of an ALC board on the rim. 1... Lightweight aerated concrete board (ALC board), 2... Wooden rim, 3... Outer periphery gap of hole cut by wood screw screw, 4... Wood screw head, 5... Wood screw head 6... A hole in lightweight cellular concrete cut by the head of a wood screw, 7... Powdered lightweight cellular concrete discharged from the notch in the head of a wood screw,
a... Wood screw head 4, b... Hole for screwdriver, c...
...Notch part 5 of the head, d...Diameter of the wood screw shaft, e
...The diameter of the screw shaft.