JP2001289222A - Exterior wall material fitting structure in building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exterior wall material fitting structure in a building, particularly a structure of fitting and fixing an exterior wall material formed of a cement compressed board, to a support member. SOLUTION: In this structure of fitting and fixing the exterior wall material formed of the cement compressed board, to the support member, a self-advancing screw piercing the support member from the back face side of the exterior wall material, is screwed into the back face of the exterior wall material. The self-advancing screw forms a thread spirally extending along the outer periphery of a shank having a head at the tail end and a gimlet point at the tip. The ratio D/d of a thread ridge diameter D to a thread root diameter d is set to 1.9>D/d>1.5, and the ratio D/P of the thread ridge diameter D to a thread pitch P is set to 2.0>D/P>1.6. Further, a flank angle α of an advancing side flank, and a flank angle (β of a drawing side flank are formed to be β>α.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting an outer wall material in a building, and more particularly to a structure for mounting and fixing an outer wall material made of a cement compression board to a support member.

[0002]

2. Description of the Related Art Conventionally, an outer wall material as a siding board in a building is made of ALC made of foamed concrete.
However, in recent years, development for high strength and thinness has been promoted, and a high-density cement compression board has been proposed.

[0003] Therefore, when the outer wall material made of such a cement compression board is attached to a building, a method of fixing the outer wall material to a support member such as a pier or a section steel from the surface side of the outer wall material with a nail or a tapping screw or the like is performed. . However, if a head such as a nail or a tapping screw is exposed on the surface of the outer wall material, there is a sense of incompatibility with the outer wall material, and
Due to the problem of rusting on the exposed head, it has been practiced to bury the head in a counterbore formed in the outer wall material and backfill it with a filler such as putty.

FIG. 5 shows an outer wall material attached by such a conventional construction method. In a state where the outer wall material 2 is attached to a support member 1 such as a crosspiece or a shape steel, the outer wall material 2 is attached from the front side. Then, the tapping screw 3 is screwed into the support member 1, and the pilot hole 4 of the support member 1 is tightened by tapping. The tapping screw 3 forms a thread 8 that extends helically along the outer circumference of a shank 7 having a head 5 at the tail end and a Gimmune point 6 at the tip. As described above, in order to bury the head 5 of the screw 3, a counterbore 9 is formed in the surface of the outer wall material 2 prior to screwing, and the head 5 is buried in the counterbore 9 to fill with putty or the like. The agent 10 is filled. The outer wall material 2 is provided with a relief 11 representing a tile pattern or other uneven pattern on the surface.

[0005]

According to the conventional method, a counterbore 9 is formed in the outer wall material 2 in accordance with the screwing position of the tapping screw 3, and after the screwing, the counterbore 9 is backfilled with the filler 10. Since it must be done, the number of man-hours is large and the cost is large. Further, the filler 10 may fall off from the counterbore 9 due to aging, and there is a problem in quality.

Therefore, the present inventor does not employ a configuration in which the tapping screw 3 is screwed to the screw-in support member 1 from the front surface side of the outer wall material 2 as in the conventional construction method. If the self-threading screw is passed through the support member and screwed into the back surface of the outer wall material (hereinafter referred to as the method of the present invention), the number of working steps can be reduced, and the surface of the outer wall material is beautiful. It has been found that it is advantageous because it can be maintained in a state.

However, according to the method of the present invention, the fixing and fixing force between the support member and the outer wall material depends on the screwing force of the self-threading screw screwed into the outer wall material. Since the length of the self-screw screw must be formed short so as not to penetrate from the back surface to the front surface, how to increase the screwing force of the screw to the outer wall material is an issue. As described above, the outer wall material made of the cement compression board is denser and harder than the conventional ALC made of foamed concrete, but still has a brittle property, so that the pull-out strength of the self-threading screw screwed into the outer wall material is reduced. Special development is required to satisfy the requirements.In addition, the screwing property is good and it can be screwed into the outer wall material with low screwing torque, but the female thread formed on the outer wall material is crushed and idles. Special development is necessary to satisfy the trade-off condition of increasing the idling torque so as not to cause the problem.

[0008]

SUMMARY OF THE INVENTION The present invention provides a structure for mounting an outer wall material in a building which has solved the above-mentioned problems. In the structure for attaching and fixing the outer wall material, a self-screw screw that penetrates the support member from the back surface side of the outer wall material is screwed into the back surface of the outer wall material, and the self-screw screw has a head at a tail end. A thread extending spirally along the outer periphery of the shank having a Gimmune point at the tip, and the ratio (D / d) of the thread diameter D and the thread root diameter d of the thread is 1.9> D / d> 1.5 and the ratio of thread diameter D to thread pitch P (D / P)
2.0> D / P> 1.6, and the flank angle α of the entry-side flank and the flank angle β of the extraction-side flank of the screw thread are formed such that β> α.

In the embodiment of the present invention, the flank angle α of the entry flank is preferably about 15 degrees, and the flank angle β of the extraction flank is preferably about 40 degrees.

It is preferable that the angle of the Gimmune point is formed in a range from 30 degrees to 40 degrees.

Further, it is preferable that the thread extends to the point of the Gimmune point at the thread pitch P.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

(Structure of Self-Screw Screw) As shown in FIG. 1, a self-screwing screw 12 used to carry out the present invention is used.
Has a head 13 at the tail end and a gymne point 14 at the tip
Is formed along the outer periphery of the shank 15 having a spiral shape. The head 13 is provided with an engaging portion 13e of a rotary tool such as a plus groove or a minus groove, and FIG. 1 shows a so-called truss head that bulges in a substantially spherical shape. It may be formed in a so-called dish head as shown in FIG.

As shown in FIG. 3, when the thread diameter of the thread 16 is D and the thread root diameter is d, the thread diameter D and the thread root diameter d
Are formed such that 1.9> D / d> 1.5, preferably 1.8 ≧ D / d ≧ 1.6. Also,
When the thread pitch is P, the thread diameter D and the thread pitch P
Are formed such that 2.0> D / P> 1.6, preferably 1.8 ≧ D / P ≧ 1.7. Screw 1
The thread No. 6 has an entry flank (flank toward the Gimmune point) 16f and a withdrawal flank (flank toward the head) 16r. Side flank 16r
Are formed at an unequal angle where β> α, preferably α is formed at about 15 degrees and β is formed at about 40 degrees. In FIG. 3, the approach direction is indicated by an arrow F. Further, as shown in FIG. 1, the angle Q of the gymne point 14 is 40 degrees ≧ Q ≧ 30 degrees, preferably 35 degrees ≧ Q
≧ 30 degrees, and the thread 16
By extending the tip 14p of the gymné point 14 as it is, an introduction thread portion 16g is formed, which gradually reduces the diameter of the thread at the tip 14p.

(Attaching Structure of Outer Wall Material) The attaching structure of the outer wall material using such a self-threading screw 12 is implemented by the above-described method of the present invention. That is, as shown in FIG.
In the state in which the self-screw screw 12 is formed through the support member 17 on the back side of the outer wall
And screwed into the back surface of the outer wall material 18 and self-screwed and fastened. The outer wall material 18 is made of a cement compression board as described above, and is preferably reinforced by mixing a fibrous material such as wood fiber. The screwing of the self-threading screw 12 into the back surface of the outer wall material 18 starts from the approach of the Gimmune point 14 formed at the angle Q as described above. The screwing is started while biting, and the screw 16 of the succeeding shank 15 then self-screws. Such a screwing operation is performed by a driving rotary tool such as an air driver, but the self-screwed screw 12 does not idle inside the outer wall material 18 even at the end of the fastening. Usually, the thickness of the outer wall material 18 composed of a cement compression board for the purpose of thinning is about 30 mm, and the surface is provided with a relief 20 representing a tile pattern or other uneven pattern,
The threaded length of the self-threading screw 12 is within 15 mm, preferably about 12 mm.

In the present invention, the thread shape defined by the flank angles α and β as described above, the ratio (D / d) between the thread diameter D and the thread root diameter d, the thread diameter D and the thread pitch P (D / P), the angle Q of the gymné point 14
Is a numerical value obtained from repeated experiments, and explains the results of the experiment based on the table.

Regarding the shape of the thread, the flank angles α and β
Table 1 shows the results of experiments conducted on the basis of a test product in which was changed as follows.

[Table 1]

Ratio of thread diameter D to thread root diameter d (D / d)
Table 2 shows the results of experiments conducted on the basis of the test product modified as follows. The self-threading screw aimed at by the present invention is required to have a low screwing torque A and a high idling torque B. Therefore, a screw with a large A / B ratio was evaluated as good and a screw with a small A / B ratio was evaluated as bad.

[Table 2]

The ratio of the thread diameter D to the thread pitch P (D /
With respect to P), Table 3 shows the results of experiments performed on the basis of test articles modified as follows. In the table, A / B indicates the ratio between the screwing torque A and the idling torque B as described above. In addition, it has been found that the pull-out resistance is caused by the presence or absence of clogging of the thread by cutting powder when the thread is screwed into the outer wall material, and is affected by the quality of the screwability.

[Table 3]

With respect to the angle Q of the Gymné point 14,
Table 4 shows the results of experiments performed on the basis of the test product modified as follows. It has been found that the pull-out resistance is affected by the effective length of the screw and the screw-in property because the screw-in depth is limited to be short in the method of the present invention.

[Table 4]

The above experimental results show a relative evaluation rather than an absolute evaluation. When these are comprehensively evaluated, the shape of the thread is determined by the flank angle α of the entry flank 16f and the flank angle α of the extraction flank 16r. The flank angle β is preferably an unequal angle that satisfies β> α, and according to further experimental results, the unequal angle in which α is formed at about 15 degrees and β is formed at about 40 degrees is the best mode.

Further, the ratio of the thread diameter D to the thread root diameter d (D
/ D) is 1.9> D / d> 1.5, preferably 1.8
≧ D / d ≧ 1.6, and the best mode is to form such that D / d is about 1.8.

The ratio (D / P) of the thread diameter D to the thread pitch P is 2.0> D / P> 1.6, preferably 1.8 ≧ D / P ≧ 1.7.

Further, the angle Q of the gymne point 14 is
40 degrees ≧ Q ≧ 30 degrees, preferably 35 degrees ≧ Q ≧ 30 degrees.

[0025]

According to the present invention, the self-threading screw 12 is provided on the back side of the outer wall member 18 made of a cement compression board.
Is penetrated through the support member 17 and screwed into the back surface of the outer wall material 18 to be screwed.
The number of working steps can be reduced, and the surface of the outer wall material can be maintained in a beautiful state.

By the way, in the case of the mounting structure according to such a construction method, the screw-in length of the self-threading screw 12 must be formed short so as not to penetrate from the back surface to the front surface of the outer wall material 18. It is difficult to increase the contact force, and furthermore, it is easy to cause slippage at the time of tightening, making it difficult to securely tighten, and further, it is not allowed to drill a prepared hole in the outer wall material 18 for the purpose of reducing the number of work steps, According to the present invention, there is a great difficulty in the driving property, and the ratio (D) of the thread diameter D and the thread root diameter d of the thread is adjusted according to the present invention.
/ D) is set to 1.9> D / d> 1.5, and the ratio (D / P) of the thread diameter D to the thread pitch P is 2.0> D
/P>1.6, and the flank angle α of the entry flank and the flank angle β of the extraction flank of the screw thread are formed so as to satisfy β> α, and more preferably the flank angle of the entry flank. α is set to about 15 degrees, the flank angle β of the flank on the extraction side is set to about 40 degrees, and the angle of the Gimmune point is formed to be not less than 30 degrees and not more than 40 degrees. Based on the self-threading screw 12 provided in the above, it is possible to realize good screwing with a low torque and to set a high limit of the idling torque, and to make it possible to attach and fix with a large pull-out resistance. It has an extremely excellent effect.

[Brief description of the drawings]

FIG. 1 is a front view showing one embodiment of a self-threading screw used for an outer wall material mounting structure according to the present invention.

FIG. 2 is a cross-sectional view showing one embodiment of an outer wall material mounting structure according to the present invention.

FIG. 3 is an enlarged sectional view showing a fixing portion between a self-threading screw and an outer wall material.

FIG. 4 is a cross-sectional view showing an embodiment of an outer wall material mounting structure using a self-threading screw having a countersunk head.

FIG. 5 is a cross-sectional view showing a mounting structure of an outer wall material according to a conventional example.

[Description of Signs] 12 Self-Screw Screw 13 Head 14 Gymne Point 14p Pointed End 15 Shank 16 Screw 16f Entry Flank 16r Extraction Flank 16g Introducing Thread 17 Support Member 18 Outer Wall Material D Thread Diameter d Screw Root diameter P Thread pitch α Entry flank angle β Extraction flank angle Q Angle of Gimmune point

Claims (4)

[Claims] 1. A structure for attaching and fixing an outer wall material made of a cement compression board to a support member, wherein a self-screw screw that penetrates the support member from the back surface side of the outer wall material is screwed into the back surface of the outer wall material. The self-threading screw has a head at the tail end and
A thread extending spirally along the outer circumference of the shank having points is formed, and the ratio (D / d) between the thread diameter D and the thread root diameter d of the thread is 1.9> D / d> 1. 5, the ratio (D / P) of the thread diameter D to the thread pitch P is 2.0> D / P> 1.6, and the flank angle α of the flank on the entry side and the drawing side on the thread. A mounting structure for an outer wall material in a building, wherein a flank angle β of the flank is formed so that β> α. 2. The flank angle α of the approaching flank is set to about 15
The mounting structure for an outer wall material in a building according to claim 1, wherein the flank angle β of the drawing-out flank is formed at about 40 degrees. 3. The mounting structure of an outer wall material in a building according to claim 1, wherein the angle of the gymné point is formed in a range of 30 degrees or more and 40 degrees or less. 4. The screw thread remains at the thread pitch P.
The mounting structure for an outer wall material in a building according to claim 1, 2 or 3, wherein the mounting structure is extended to a point of the point.