JP2002031114A - Screw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screw as a wood screw, for example, a screw used for fixing and holding a roof tile to a roof component. SOLUTION: In the screw having a pointed end on a tip of a shank and a head part on a tail end, the shank is successively constituted of at least a first shank part, a second shank part, and a third shank part which extend from the pointed end to the head part, a preceding thread part is formed on the first shank part, a reamer part is formed on the second shank part, and a succeeding thread part is formed on the third shank part. Inequalities D1>d1>R1 and D2>d1>R2 are satisfied, where D1 and R1 are the diameter at the ridge of thread and the diameter at the bottom of thread of the preceding thread part, respectively, d1 is the outside diameter of the reamer part, and D2 and R2 are the diameter at the ridge of thread and the diameter at the bottom of thread of the succeeding thread part, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw, particularly a wood screw screw, for example, a screw used for fixing and holding a roof tile to a roof component.

[0002]

2. Description of the Related Art Roof tiles (hereinafter simply referred to as "tiles") laid on a roof component are not only displaced when subjected to a strong wind due to a typhoon or the like, but also cause a leak,
There is a danger of being hit by a storm and causing an accident when falling.

Therefore, in order to firmly fix the laid tile to the roof component, a technique of fixing the tile to the roof component with screws has been implemented. For this purpose, a hole for inserting the screw is provided. A preformed roof tile is provided.

[0004] Since wood is used for the roof component, a known screw has a sharp end at the tip of the shank, a head at the tail end, and a wood screw having a thread formed on the outer periphery of the shank. Configure the screw. When fixing and holding the tile, the screw is inserted into the hole of the roof from above the tile, the sharp end is pierced into the roof component, and the shank is screwed into the roof component while driving and rotating with a tool. It is configured to be screwed in and held by holding the top surface of the tile with the head of the screw.

[0005]

Since the work of laying a tile usually covers a very large number of tiles, the work of screwing wood screw screws for fixing and holding each tile is performed quickly to shorten the work time. Is required. In this regard, the screw travel distance per rotation of the screw is proportional to the pitch of the thread,
In order to enable the screw to be screwed in quickly, it is desirable to form a so-called coarse thread in which the pitch of the thread is increased.

However, in recent years, relatively hard members called so-called boards have been used as roof constituent members. For this reason, when screwing a wood thread screw into such a hard member, when screwing a coarse thread formed over the entire length of the shank of the screw into the hard member, an extremely large torque is required to drive and rotate the screw, There is a risk that the tool engaging portion on the head of the screw may be damaged, or the screw may not be able to rotate during the screwing.

[0007]

SUMMARY OF THE INVENTION According to the present invention, the above-mentioned problems have been solved, and a screw can be quickly screwed into a work (a roof component) by a coarse thread at an initial stage of screwing, and a screw which is to be subsequently screwed into a workpiece (roof component) can be obtained. At the subsequent stage of the insertion, a screw is provided which can also reduce the torque required for the drive rotation, while also maintaining the rapid threading by the coarse thread.

[0008] The purpose of such torque reduction is to form a hole in the work by screwing a leading thread portion forming a coarse thread into the work, and then enlarge the hole by a reamer portion which subsequently enters. Then, when the subsequent thread portion forming the course thread is allowed to enter the hole,
This is achieved by making the following thread portion easy to screw into the hole.

By the way, since the hole of the work is enlarged by the reamer, it is easy to screw in the subsequent thread portion, but the valley portion of the subsequent thread portion is not guided by the enlarged hole of the work. In this case, the straightness of screw insertion is degraded. In this regard, according to the present invention, according to the present invention, the succeeding thread portion constitutes a double thread composed of the first thread having the mountain height and the second thread having the mountain lower, and the second thread having the mountain lower is formed. Since the screw is guided and screwed into the enlarged hole of the work, a screw having excellent straightness is provided.

Further, in the case of a screw for fixing a tile, a blank without a thread is provided between a shank portion with a thread to be screwed into a roof component and a head for holding and holding the tile from above. The shank portion thus formed is formed, which causes a problem in strength at that portion. According to the present invention, a screw having a high shank portion of the blank is provided.

Therefore, the present invention is configured as a first means, in a screw provided with a sharp end at the tip of the shank and a head at the tail end, the shank is directed from the sharp end toward the head. At least a first shank portion, a second shank portion, and a third shank portion extending are sequentially formed, a leading thread portion is formed in the first shank portion, a reamer portion is formed in the second shank portion, and a third shank portion is formed in the third shank portion. The following thread portion is formed, the leading thread portion has a peak diameter of D1 and a root diameter of R1, the outer diameter of the reamer portion is d1, the trailing thread portion has a peak diameter of D2, and a root diameter of R2. Then, D1>d1> R1 and D2>
d1> R2.

Next, the present invention is configured as a second means, in a screw provided with a sharp end at the tip of the shank and a head at the tail end, the shank is directed from the sharp end toward the head. At least a first shank portion, a second shank portion, and a third shank portion extending are sequentially formed, a leading thread portion is formed in the first shank portion, a reamer portion is formed in the second shank portion, and a third shank portion is formed in the third shank portion. A first thread and a second thread are formed by forming a subsequent thread forming a two thread, the leading thread has a peak diameter of D1 and a valley diameter of R1, and an outer diameter of the reamer. Is d1, the crest diameter of the first thread of the subsequent thread is D2 and the valley diameter is R2, and the crest diameter of the second thread of the subsequent thread is d2.
D1>d1> R1, and D2>d1> R
2 and d2 ≧ d1.

Both the leading thread portion and the first thread of the trailing thread portion constitute a coarse thread having a pitch larger than that of a normal wood screw, and the pitch of the leading thread portion is P1. When the pitch of the first thread of the succeeding thread portion is P2, it is preferable that P1 and P2 be substantially equal to P1 = P2.

In a preferred embodiment of the present invention, the shank has at least a first portion extending from the sharp end toward the head.
The shank portion, the second shank portion, the third shank portion, and the fourth shank portion are sequentially formed, and the fourth shank portion forms a work hardened portion having a knurled surface on a peripheral surface.

[0015]

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

As shown in FIG. 1, the screw 1 is made of a metal having excellent corrosion resistance (austenitic stainless steel or iron material which has been formed and then subjected to rust prevention treatment). And a head 3 at a tail end thereof, and the shank has at least a first shank portion 4, a second shank portion 5, a third shank portion 6 extending continuously from the sharp end 2 toward the head 3. The fourth shank portion 7 is sequentially formed.

The sharp end 2 forms a notched vertical groove 8 extending in the axial direction from the front end. As shown in FIG.
Is provided with an engaging portion 9 formed of a plus groove, a minus groove or the like at the top, and the screw 1 is driven to rotate by engaging a rotary driving tool with the engaging portion 9. The head 3 has a flange 10, and a neck 11 formed between the fourth shank 7 and the head 3 is formed in a tapered shape whose outer diameter gradually increases toward the flange 10, and a peripheral surface of the neck 11. An annular groove 12 forming a continuous surface is formed on the lower surface of the flange 10.

As shown in FIG. 1, the first shank portion 4
A preceding thread portion 1 constituting a course thread as described later.
The leading thread portion 13 extends to near the tip of the sharp end 2. The second shank part 5 constitutes a reamer part 14 in which the peripheral surface of the blank shank having no thread is subjected to knurling. The third shank portion 6 forms a subsequent thread portion 15, which comprises a first thread 16 having a mountain height and a second thread 17 having a mountain height.
A first thread 16 having a mountain height constitutes a course thread as described later, and a second thread 17 having a lower mountain constitutes a straight guide means as described later. The fourth shank part 7 constitutes a work hardening part 18 in which the peripheral surface of the blank shank having no thread is subjected to knurling.

FIG. 2 shows an embodiment in which the above screw 1 is used for fixing a roof tile. The roof tile 19 is previously provided through a hole 20 and is sequentially laid on a roof component 23 having a base member 21 and a pillow member 22 made of wood. Although not shown, the adjacent tiles are laid so as to overlap each other, and the holes 20 of the previously laid tile 19 are laid.
The next tile to be laid next is overlaid on top of the. At the time of the laying operation, the hole 20 of the roof tile 19 is filled with the sealing agent 24 made of silicon or the like. In this state, the screw 1 is inserted through the hole 20 through the sealing agent 24 while rotating the screw 1 by the rotary driving tool. 2, the leading thread portion 13, the reamer portion 14, and the trailing thread portion 15 are screwed and fixed to the pillow member 22 and the base member 21, and the flange 1 of the head 3 of the screw 1 is fixed.
0 presses and holds the upper surface of the tile 19. In this state,
As shown in FIG. 3, the sealing agent 24 is filled between the hole 20 of the roof tile 19 and the fourth shank portion 7 and the neck portion 11 of the screw 1, and the annular groove 1 formed on the lower surface of the flange 10.
2 to seal the hole 20 in a watertight manner.

FIG. 4 shows a characteristic configuration of the present invention.
As shown in FIG. 4A, the leading thread portion 13 provided on the first shank portion 4 forms a coarse thread in which the thread pitch P1 is relatively large and coarse. For example, the outer diameter of the first shank portion 4 is 4.3 mmφ and the length is 25 mm.
mm, the leading thread portion 13 is formed at 9 ridges / inch, so that the pitch P1 in this case is about 2.
8 mm, forming a so-called course thread. By the way, in order to form such a coarse thread, the leading thread portion 13 has a larger difference between the peak diameter D1 and the valley diameter R1 than a normal thread. That is, when forming a thread with a rolling die on a shank material, the larger the thread pitch, the more the extra thickness generated from a wide valley must be moved to the peak, and the peak becomes higher. It is. In the illustrated embodiment, the crest angle θ1 of the leading thread portion 13 is about 60 degrees.

As shown in FIG. 4B, the reamer portion 14 provided on the second shank portion 5 is formed by processing a knurled knurl on the peripheral surface of the blank shank, and has a large number of knurled grooves. 25 knurled teeth are provided. Therefore, the outer diameter d1 of the reamer 14 is smaller than the peak diameter D1 and larger than the valley diameter R1 of the preceding thread portion 13, that is, D1>d1> R1.

The succeeding thread portion 15 is provided with a first thread 16 of mountain height.
Thus, a coarse thread having a relatively large thread pitch P2 is formed. In the illustrated embodiment, the pitch P2 of the first thread 16 is substantially equal to the pitch P1 of the preceding thread portion 13, that is, P2 = P1. Therefore, in the case of the illustrated example, the number is 9 peaks / inch (pitch P2 is about 2.8 mm), and a so-called coarse thread is formed.

As described above, the trailing thread portion 15 is composed of the first thread 16 having a high mountain height and the second thread 1 having a low mountain height extending in a parallel spiral shape with the first thread 16 having a high mountain height.
7 are provided. Naturally, the thread pitch of the second thread 17 is equal to that of the first thread 16 to form the two thread.
Is substantially equal to the thread pitch P2 of the second thread 17 in this embodiment, but in the present embodiment, the ridge of the second thread 17 is disposed at the center between two adjacent ridges of the first thread 16. The interval P3 between the peaks of the first thread 16 and the second thread 17 is:
P2 ・.

Subsequent thread portion 1 composed of such a double thread
5 is formed on the shank material by a rolling die in the same manner as described for the preceding thread portion 13. At this time, since the first thread 16 forms a coarse thread, the difference between the peak diameter D2 and the valley diameter R2 is made larger than that of a normal thread. In this regard, since the second thread 17 is formed simultaneously with the first thread 16, the first thread 16 is formed.
It is difficult to form the ridge diameter D2 of the first thread portion 13 at a height substantially equal to or equal to the ridge diameter D1 of the preceding thread portion 13. Therefore, in the case of the illustrated embodiment, the leading thread portion 13
The peak angle θ2 (about 40 degrees) of the first thread 16 is smaller than the peak angle θ1 (about 60 degrees), that is, θ1> θ2. By forming the first thread 16 thin as described above, the second thread 17 ( The trailing thread portion 15 having a peak angle θ3 of about 60 degrees)
Enables molding. Article 2 thread diameter d2 of thread 17
Is d2 ≧ d with respect to the outer diameter d1 of the aforementioned reamer portion 14.
It is one. FIG. 4B illustrates the case where d2 = d1, but the configuration may be such that d2> d1. Then, the peak diameter D2 and the root diameter R2 of the first thread 16 are determined.
D1 and d2 are located between, that is, D2> d2 ≧ d
1> R2.

According to the above configuration, when the screw 1 is screwed into the roof component 23 from the sharp end 2 and screwed into the roof component 23, first, as shown in FIG. In the initial stage of the screwing into which the shank portion 4 enters, a quick screwing is performed by the course thread formed by the preceding screw portion 13, and thereafter, as shown in FIG. In the stage, the screw thread is also quickly screwed in by the coarse thread constituted by the first thread 16 of the succeeding thread section 15, but the driving torque of the screw 1 during this time is reduced.

That is, when the first shank portion 4 provided with the leading thread portion 13 enters, the roof component 23 has a hole 26a having an inner diameter equal to the root diameter R1 and a female screw groove formed in the hole 26a. Is formed (FIG. 4A), but the hole 26a is cut and enlarged by the reamer portion 14 that subsequently enters,
A hole 26b having an enlarged inner diameter is formed (FIG. 4).
(B)).

For this reason, since the subsequent thread portion 15 enters the hole 26b enlarged by the reamer portion 14 first, the entry is easy, and the torque required for driving and rotating the screw 1 as a whole is reduced. I do. The subsequent thread portion 15 forms a double thread composed of the first thread 16 having a mountain height and the second thread 17 having a mountain height, and the first thread 16 having a mountain height is formed with a female thread groove in the hole 26b. Screw in while engraving. At this time, if the crest diameter d2 of the second thread 17 at the crest and the inner diameter d1 of the hole 26b are set to d2 = d1, the second thread 17 at the crest is aligned with the hole 26b. The approach direction of the three shank portions 6 is guided in the straight traveling direction. On the other hand, the crest diameter d2 of the second thread 17 at the crest
Even when the inner diameter d1 of the hole 26b is set to d2 ≧ d1, the crest of the second thread 17 at the crest easily enters the hole 26b and enters the straight direction while being guided along the hole 26b.

As a result, the leading thread portion 13 in the first shank portion 4 and the trailing thread portion 1 in the third shank portion 6
5, the first thread 16 has the respective pitch P1.
And a coarse pitch coarse thread having relatively large P2 is formed to increase the screwing distance per rotation, but the torque required to drive and rotate the screw is reduced as a whole. As described above, even when the roof component member 23 is made of a hard member called a board or the like, the screw 1 can obtain a large thrust with a relatively light driving torque, and the time required for installing the tile can be reduced. It greatly contributes to shortening.

As shown in FIG. 2, when the screw 1 is screwed, the reamer 14 does not penetrate the roof component 23 but remains inside a part thereof (the base member 21 in the figure). With such a configuration, the reamer portion 1 is inserted into the hole 26a formed by the first shank portion 4.
Since the screw 4 bites and stops, the screw 1 is prevented from reversing and functions as a slack stop.

Further, in a state where the roof 19 is fixedly held by the head 3 of the screw 1, a fourth shank portion 7 extends below the head 3 via a neck portion 11, and the direction of displacement of the roof 19 ( With respect to the movement in the (lateral direction), the fourth shank portion 7 receives a force in the bending direction or the shearing direction. In this regard, since the fourth shank portion 7 has the work hardened portion 18 formed by knurling the peripheral surface, the fourth shank portion 7 has sufficient strength to withstand bending or shearing. That is, as described above, when the screw 1 is formed of austenitic stainless steel (for example, SUS304, XM-7) having more excellent corrosion resistance, reinforcement by ordinary quenching cannot be expected.
Therefore, particularly in the case of a screw for holding a roof tile, it is advantageous to form a work hardened portion 18 by knurling in the fourth shank portion 7 which is required to have strength against bending or shearing. According to the configuration of the knurling process, there is an effect that the adhesion with the sealing agent 24 filled in the hole 20 of the tile is improved as described above.

[0031]

According to the first aspect of the present invention, the first
The ridge diameter of the preceding thread portion 13 formed on the shank portion 4 is D1 and the valley diameter is R1, the outer diameter of the reamer portion 14 formed on the second shank portion 5 is d1, and the succeeding portion formed on the third shank portion 6 is When the crest diameter of the thread portion 15 (first thread 16) is D2 and the valley diameter is R2, D1>d1> R1 and D2>.
d1> R2, the leading thread portion 13
The hole 26a formed in the workpiece (the roof component member 23) by the entry of the first shank portion 4 provided with the first shank portion 4 is cut by the reamer portion 14 that subsequently enters, and is formed in the hole 26b whose inner diameter is enlarged. The succeeding subsequent thread portion 15 easily enters the hole 26b, and reduces the torque required for driving and rotating the screw 1 as a whole. As a result, the leading thread portion 13 of the first shank portion 4 and the trailing thread portion 15 (first thread 16) of the third shank portion 6 are each pitch P1.
And P2 is formed into a relatively large course thread so that a quick screwing operation can be performed.
The torque required for screw driving rotation is small, especially
Even when the work (the roof component member 23) is made of a hard member, a large thrust can be achieved with a light driving torque, and further, after screwing, the reamer portion 14 does not bite into the work to prevent loosening by preventing reverse rotation. There is an effect that the enabled screw can be provided.

According to the second aspect of the present invention, the subsequent thread portion 15 of the third shank portion 6 is composed of the first thread 16 having a high mountain and the second thread 17 having a low mountain. When the thread is formed and the crest diameter of the second thread 17 is d2, the second thread 17 enters along the inner surface of the hole 26b of the work cut and enlarged by the reamer portion 14, Since the ridge diameter d2 of the second thread 17 and the outer diameter d1 of the reamer 14 are formed so as to satisfy d2 ≧ d1, the third shank 6 is formed into the hole 2 as described above.
6b, the straightness of the approach can be maintained.

According to the third aspect of the present invention, the pitch P1 of the preceding thread portion 13 and the pitch P2 of the first thread 16 of the succeeding thread portion 15 are substantially equal to P1 = P2. However, since any of them can be formed into a coarse thread, it is possible to provide a screw excellent in the speed of the above-described operation.

Further, according to the present invention as set forth in claim 4,
Even when formed of austenitic stainless steel that cannot be strengthened by ordinary quenching, the fourth shank portion 7 that is required to have bending resistance or shearing resistance especially for a screw for holding a roof tile has a work hardened portion 18 formed by knurling. Since it is formed, it is possible to sufficiently withstand bending and shearing, and according to the configuration of knurling,
There is a one-stone-two-bird effect that the adhesion to the sealant 24 filled in the hole 20 of the tile is improved.

[Brief description of the drawings]

FIG. 1 is an external view showing an embodiment of the present invention.

FIG. 2 is an explanatory view showing an example in which a roof tile is fixed and held on a roof component using screws according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a sealing portion when a roof tile is fixedly held to a roof component using a screw according to one embodiment of the present invention.

4A and 4B show the operation of a screw according to an embodiment of the present invention, wherein FIG. 4A is a cross-sectional view showing a preceding thread portion at an initial stage of screwing into a work, and FIG. It is sectional drawing which shows the reamer part and the following thread part in the following stage.

[Explanation of symbols]

 Reference Signs List 1 screw 2 sharp end 3 head 4 first shank part 5 second shank part 6 third shank part 7 fourth shank part 13 preceding thread part 14 reamer part 15 succeeding thread part 16 first thread 17 Screw thread 18 Work hardening part 19 Tile 20 Tile hole 21 Base member 22 Pillow member 23 Roof component 24 Sealant 26a, 26b Work hole

Claims (4)

[Claims] 1. A screw having a sharp end at a tip end thereof and a head at a tail end, wherein the shank extends from the sharp end toward the head, at least a first shank portion, a second shank portion and a second shank portion. Three shank portions are sequentially formed, a leading thread portion is formed in the first shank portion, a reamer portion is formed in the second shank portion, and a trailing thread portion is formed in the third shank portion. D1>d1> R1 and D2>, where D1 is the crest diameter of the thread portion, R1 is the trough diameter, D1 is the outer diameter of the reamer portion, and D2 is the crest diameter of the subsequent thread portion. d1
> A screw formed in R2. 2. A screw having a sharp end at a tip end thereof and a head at a tail end thereof, wherein the shank extends from the sharp end toward the head, at least a first shank portion, a second shank portion and a second shank portion. Three shank portions are sequentially formed, a first thread portion is formed in the first shank portion, a reamer portion is formed in the second shank portion, and a first thread and a second thread are formed in the third shank. A first thread of the succeeding thread is formed by forming a trailing thread portion constituting the thread thread, a ridge diameter of the preceding thread portion being D1 and a valley diameter of R1, an outer diameter of the reamer portion being d1, and a first thread of the succeeding thread portion. D is the thread diameter
2 and the root diameter are R2, and the crest diameter of the second thread of the succeeding thread is d2, D1>d1> R1 and D2> d1
> R2, wherein d2 ≧ d1. 3. When the pitch of the preceding thread portion is P1 and the pitch of the first thread of the succeeding thread portion is P2, P1 and P
The screw according to claim 1 or 2, wherein 2 is formed substantially at P1 = P2. 4. A shank extending at least from a sharp end toward a head to sequentially form at least a first shank portion, a second shank portion, a third shank portion, and a fourth shank portion, and the fourth shank portion is knurled on a peripheral surface. The screw according to claim 1, 2 or 3, wherein a processed hardened portion is formed.