JP3436734B2 - Screw - Google Patents

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, and for example, to a screw used for fixing and holding a roof tile to a roof component.

[0002]

2. Description of the Related Art A roof tile (hereinafter simply referred to as "tile") laid on a roof constituent member not only causes a positional shift when it receives a strong wind due to a typhoon or the like, but also causes a rain leak,
There is a danger of being blown away by the wind and causing an accident when falling.

Therefore, in order to firmly fix the laid roof tile to the roof constituent member, a technique for fixing the roof tile to the roof constituent member with a screw has been carried out. For this purpose, a hole for inserting the screw is provided. Preformed roof tiles are provided.

Since wood is used for the roof component, the known screw is a wood screw in which a sharp end is provided at the shank and a head is provided at the tail end, and a thread is formed on the outer periphery of the shank. Make up a screw. When fixing and holding the roof tile, insert the screw from above the roof tile into the hole of the roof tile, pierce the roof component with the sharp end, and rotate the tool to rotate the shank to the roof component. It is configured to be screwed in, and the top of the roof tile is pressed and held by the head of the screw.

[0005]

Since the roof tile laying work usually covers an extremely large number of roof tiles, it is necessary to quickly screw in the wood screw screws for fixing and holding each roof tile to shorten the work time. Is required. In this regard, the screw travel distance per revolution of the screw is proportional to the pitch of the thread,
In order to allow 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.

In recent years, however, laminated members, plywood, and other so-called boards, which are relatively hard members, have been used as roof constituent members. Therefore, when a wood screw screw is screwed into such a hard member, when a coarse thread formed over the entire length of the shank of the screw is screwed into the hard member, an extremely large torque is required to drive and rotate the screw, There is a possibility that the tool engaging portion of the head of the screw may be damaged or the screw may become unrotatable during screwing.

[0007]

According to the present invention, the above-mentioned problems are solved, and quick screwing by a course thread can be performed at the initial stage of screwing into a work (roof constituting member), and subsequent screwing can be performed. A screw is provided that can reduce the torque required for driving rotation while maintaining the rapid screwing by the course thread in the subsequent stage of the turning.

The purpose of reducing the torque is to form a hole in the work by screwing the preceding thread portion formed with the coarse thread into the work, and then to enlarge it by the reamer part that successively enters the hole. , Then, when letting the subsequent threaded portion forming the course thread enter the hole,
This is achieved by arranging the trailing thread portion so that it can be easily screwed into the hole.

By the way, since the hole of the work is enlarged by the reamer portion, it is easy to screw the succeeding screw portion, but the enlarged hole of the work does not guide the valley portion of the succeeding screw portion. Therefore, the straightness of screw-in is deteriorated. In this regard, according to the present invention, the trailing screw portion constitutes a two-thread screw consisting of a first thread thread having a mountain height and a second thread thread having a mountain height, and a second thread thread having a mountain thread is formed. Since it is screwed while being guided into the enlarged hole of the work, a screw having excellent straightness is provided.

Further, in the case of the screw for fixing the roof tile, a blank without a screw thread is provided between the shank portion with the screw thread to be screwed into the roof constituent member and the head portion for pressing and holding the roof tile from above. Although the shank portion formed is formed and a problem occurs in the strength at that portion, the present invention provides a screw in which the shank portion of the blank has high strength.

[0011]

Therefore, the present invention is configured as the means , and in a screw having a sharp end at the tip of the shank and a head at the tail end, at least the shank extends from the sharp end toward the head. The first shank portion, the second shank portion, and the third shank portion are sequentially configured, the leading thread portion is formed on the first shank portion, the reamer portion is formed on the second shank portion, and the first shank portion is formed on the third shank portion. It is formed by forming a trailing screw portion that constitutes a two-thread screw of a thread thread and a second thread thread. The leading thread portion has a mountain diameter of D1 and a valley diameter of R1, and the outer diameter of the reamer portion is d1. The mountain diameter of the first thread of the succeeding thread is D2 and the valley diameter is R2, and the mountain diameter of the second thread of the succeeding thread is d2.
Then, D1>d1> R1 and D2>d1> R
2 and d2 ≧ d1.

The leading thread portion and the first thread of the trailing thread portion both constitute a coarse thread having a pitch larger than that of a normal wood screw screw, and the pitch of the leading thread portion is P1. Assuming that the pitch of the first thread of the succeeding screw portion is P2, it is preferable that P1 and P2 are formed to be approximately P1 = P2.

In a preferred embodiment of the 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 configured, and the fourth shank portion forms a work-hardened portion in which the peripheral surface is knurled.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, the screw 1 is formed of a metal having excellent corrosion resistance (austenitic stainless steel or iron material which has been subjected to rust-preventing treatment after molding) and has a sharp end 2 at the tip of the shank. And a head 3 at the tail end, and the shank has at least a first shank portion 4, a second shank portion 5, and a third shank portion 6 that extend in series from the sharp end 2 toward the head 3. The fourth shank portion 7 is sequentially configured.

The sharp end 2 forms a notched vertical groove 8 extending axially from the tip. As shown in FIG. 3, the head 3
Has an engaging portion 9 formed of a plus groove, a minus groove, or the like at the top, and the screw 1 is driven and rotated by engaging a rotary drive tool with the engaging portion 9. The head portion 3 is provided with a flange 10, and a neck portion 11 formed between the fourth shank portion 7 and the head portion 3 is formed in a taper shape whose outer diameter gradually increases toward the flange 10 and a peripheral surface of the neck portion 11. The 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 is
Leading thread portion 1 that constitutes a course thread as described later
3 is formed, and the preceding thread portion 13 extends to the vicinity of the tip of the sharp end 2. The second shank portion 5 constitutes a reamer portion 14 in which the peripheral surface of the blank shank having no thread is knurled. The third shank portion 6 forms a trailing screw portion 15, and the trailing screw portion 15 is composed of a first thread 16 having a mountain height and a second thread 17 having a mountain height.
The first thread 16 having a mountain height forms a course thread, which will be described later, and the second thread 17 having a mountain height forms a linear guide means, which will be described later. The fourth shank portion 7 constitutes a work hardening portion 18 in which the peripheral surface of the blank shank having no thread is knurled.

An embodiment in which the above-mentioned screw 1 is used for fixing a roof tile is illustrated in FIG. The roof tiles 19 are preliminarily provided through the holes 20, and are sequentially laid on a roof constituent member 23 having a base member 21 and a pillow member 22 each made of wood. Although not shown in the drawing, adjacent roof tiles are laid so as to overlap each other, and the holes 20 of the roof tile 19 laid earlier are provided.
The next roof tile to be laid next is overlaid on the upper part of the. During the laying work, the hole 20 of the roof tile 19 is filled with the sealing agent 24 made of silicon or the like, and in this state, the screw 1 is passed through the sealing agent 24 and inserted into the hole 20 while rotating the screw 1 by the rotary driving tool, and the sharp end is formed. The leading screw portion 13, the reamer portion 14, and the trailing screw portion 15 are screwed and fixed to the pillow member 22 and the base member 21 in order from 2 to the flange 1 of the head 3 of the screw 1.
The upper surface of the roof tile 19 is pressed and held by 0. In this state,
As shown in FIG. 3, the sealant 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 constitutes a coarse thread having a relatively large and coarse thread pitch P1. For example, the outer diameter of the first shank portion 4 is 4.3 mmφ and the length is 25 mm.
In the case of the embodiment with mm, the leading threaded portion 13 is formed to have 9 threads / inch, so the pitch P1 in this case is about 2.
It is 8 mm and constitutes a so-called course thread. By the way, since such a course thread is formed, the leading thread portion 13 has a larger difference between the peak diameter D1 and the valley diameter R1 than that of a normal thread. That is, when the thread is formed on the shank material with a rolling die, the larger the screw pitch, the more the surplus generated from the wide valley portion needs to be moved to the mountain portion, which increases the mountain portion. Is. In the illustrated embodiment, the ridge 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 groove 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 portion 14 is formed to be smaller than the mountain diameter D1 of the preceding thread portion 13 and larger than the valley diameter R1, that is, D1>d1> R1.

The succeeding screw portion 15 is a first thread 16 having a mountain height.
Thus, a coarse thread having a relatively large and coarse 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 13, that is, P2 = P1. Therefore, in the case of the illustrated example, it is 9 peaks / inch (pitch P2 is about 2.8 mm), and constitutes a so-called course thread.

As described above, the trailing thread portion 15 has the mountain-shaped second thread 1 extending in parallel with the mountain-height first thread 16.
7 is provided. Since the two-thread screw is configured, the thread pitch of the second-thread screw 17 is naturally the same as that of the first-thread screw 16.
In the present embodiment, the crest portion of the second thread 17 is arranged at the center between the two crest portions of the first thread 16 adjacent to each other. , The interval P3 between the peaks of the first thread 16 and the second thread 17 is
It is P2 1/2.

A succeeding screw thread portion 1 made of such a double thread
5 is molded by a rolling die on the shank material in the same manner as described for the preceding thread portion 13. At this time, since the first thread 16 constitutes a coarse thread, the difference between the peak diameter D2 and the valley diameter R2 is formed to be larger than that of the normal thread. In this regard, since the second thread 17 is molded at the same time as the first thread 16, the first thread 16
It is difficult to form the ridge diameter D2 of the front thread portion 13 substantially equal to or comparable to the ridge diameter D1 of the preceding thread portion 13. Therefore, in the illustrated embodiment, the preceding thread portion 13
The crest angle θ2 (about 40 degrees) of the first thread 16 is smaller than the crest angle θ1 (about 60 degrees), that is, θ1> θ2. By forming the first-thread thread 16 thinly in this way, the second thread 17 (while the diameter D2 of the first thread 16 is D2 = D1 which is comparable to that of the preceding thread section 13). The trailing screw portion 15 having a mountain angle θ3 of about 60 degrees)
It enables the molding of. Article 2 Thread diameter of thread 17 d2
Is d2 ≧ d with respect to the outer diameter d1 of the reamer portion 14 described above.
It is 1. In FIG. 4B, the case where d2 = d1 is illustrated, but the configuration may be such that d2> d1. Then, the ridge diameter D2 and the valley diameter R2 of the first thread 16
Between d1 and d2, that is, D2> d2 ≧ d
1> R2.

According to the above construction, when the screw 1 is screwed into the roof constituent member 23 from the sharp end 2 and screwed into the roof constituent member 23, first, as shown in FIG. In the initial stage of screwing in which the shank portion 4 enters, rapid screwing is performed by the course thread constituted by the preceding thread portion 13, and thereafter, as shown in FIG. In the step, the rapid threading is maintained by the coarse thread which is also formed by the first thread 16 of the subsequent threaded portion 15, but the driving rotational torque of the screw 1 during this time is reduced.

That is, when the first shank portion 4 having the preceding 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. 4 (A)), the hole 26a is cut and enlarged by the reamer portion 14 that is subsequently inserted,
A hole 26b having an enlarged inner diameter is formed (see FIG. 4).
(B)).

Therefore, the succeeding thread portion 15 enters the hole 26b enlarged by the reamer portion 14 first, so that it is easy to enter and the torque required to drive and rotate the screw 1 is reduced as a whole. To do. The trailing screw portion 15 forms a two-thread screw thread including a first thread thread 16 having a mountain height and a second thread thread 17 having a mountain height, and the first thread thread 16 having a mountain height is provided with a female thread groove in the hole 26b. Screw in while engraving. At this time, if the mountain diameter d2 of the mountain-shaped second thread 17 and the inner diameter d1 of the hole 26b are set to d2 = d1, the mountain-shaped second thread 17 is placed along the hole 26b. 3 Guide the approach direction of the shank portion 6 in a straight direction. On the other hand, the thread diameter d2 of the thread-like second thread 17 is low.
Even when the inner diameter d1 of the hole 26b is set to d2 ≧ d1, the crest portion of the second thread 17 having a low crest easily goes into the hole 26b while being guided along the hole 26b in a straight direction.

As a result, the leading thread portion 13 of the first shank portion 4 and the trailing thread portion 1 of the third shank portion 6 are formed.
5 and the first thread 16 are all pitch P1
And a coarse pitch coarse thread having a relatively large P2 is formed to increase the screwing distance per rotation, but the torque required for driving and rotating the screw is reduced as a whole. Even when the roof constituent member 23 is made of a hard member such as a board as described above, the screw 1 can obtain a large thrust with a comparatively light driving torque, and the roof tile installation work time can be reduced. It greatly contributes to shortening.

Then, as shown in FIG. 2, the reamer portion 14 does not penetrate through the roof constituent member 23 in the screwed state of the screw 1 and remains inside a part thereof (the base member 21 in the drawing). With this structure, the reamer portion 1 is inserted into the hole 26a formed by the first shank portion 4.
Since the 4 bites and stops, the screw 1 is prevented from reversing and functions as a loosening stopper.

Further, in a state in which the roof tile 19 is fixedly held by the head 3 of the screw 1, the fourth shank portion 7 extends below the head 3 through the neck portion 11, and the position of the roof tile 19 in the direction of displacement ( 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 a work-hardened portion 18 whose peripheral surface is knurled, it 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 a higher corrosion resistance, strengthening by normal quenching cannot be expected.
Therefore, particularly in the case of screws for holding roof tiles, it is advantageous to form the work-hardened portion 18 by knurling in the fourth shank portion 7 required to have strength against bending or shearing. Further, the knurling configuration has the effect of two birds with one stone that the adhesiveness with the sealant 24 filled in the holes 20 of the roof tile becomes good as described above.

[0031]

According to the present invention described in claim 1, the first
The leading thread portion 13 formed on the shank portion 4 has a mountain diameter D1 and a valley diameter R1, the outer diameter of the reamer portion 14 formed on the second shank portion 5 is d1, and the trailing portion formed on the third shank portion 6 When the thread diameter of the thread portion 15 (first thread 16) is D2 and the root diameter is R2, D1>d1> R1 and D2>
Since the configuration is such that d1> R2, the preceding thread portion 13
Since the hole 26a formed in the work (roof constituent member 23) by the entry of the first shank portion 4 provided with is cut by the reamer portion 14 that subsequently enters and is formed in the hole 26b having an enlarged inner diameter, The succeeding succeeding screw portion 15 easily enters the hole 26b and reduces the torque required to drive and rotate 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 respectively pitch P1.
Even when performing a quick screwing operation by forming P and P2 on a relatively large course thread,
The torque required to drive and rotate the screw is small, especially
Even when the work (roof constituent member 23) is made of a hard member, a large driving force can be achieved with a light driving torque, and after screwing, the reamer portion 14 bites into the work to prevent loosening by preventing reverse rotation. It has the effect of providing the screws that have been made possible.

In particular, according to the present invention , the trailing thread portion 15 of the third shank portion 6 constitutes a two-thread thread consisting of a first thread thread 16 having a mountain height and a second thread thread 17 having a mountain height. When the thread diameter of the second thread 17 is d2, the second thread 17 is inserted so that the second thread 17 enters along the inner surface of the hole 26b of the workpiece cut and enlarged by the reamer portion 14. Since the mountain diameter d2 of the thread 17 and the outer diameter d1 of the reamer portion 14 are formed such that d2 ≧ d1, as described above, the third shank portion 6 can be easily inserted into the hole 26b. The straightness of the approach can be maintained.

According to the present invention as set forth in claim 2 , the pitch P1 of the preceding threaded portion 13 and the pitch P2 of the first thread 16 of the trailing threaded portion 15 are substantially equal to each other, and P1 = P2. However, since any of them can be formed into a course thread, it is possible to provide a screw having excellent promptness of the work as described above.

Further, according to the present invention as set forth in claim 3 , even when it is formed of austenitic stainless steel, which cannot be expected to be strengthened by ordinary quenching, bending resistance or shear resistance is particularly high in the roof tile holding screw. The fourth shank portion 7 required is a work hardening portion 18 by knurling.
Since it is formed, it is possible to sufficiently withstand bending and shearing, and further, due to the knurling structure, the adhesiveness with the sealing agent 24 filled in the holes 20 of the roof tile is improved. It has the effect of two birds with one stone.

[Brief description of 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 fixedly held on a roof constituent member using a screw according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a seal portion when a roof tile is fixedly held on a roof constituent member using a screw according to an embodiment of the present invention.

4A and 4B show the operation of a screw according to an embodiment of the present invention, 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 a sectional view showing a reamer part and a succeeding screw part at a subsequent stage.

[Explanation of symbols]

1 screw 2 sharp tip 3 heads 4 First shank part 5 Second shank part 6 Third shank part 7 4th shank part 13 Leading thread 14 Reamer 15 Subsequent screw part 16 Article 1 Thread 17 Article 2 Thread 18 Work hardening part 19 roof tiles 20 tile holes 21 Base member 22 Pillow material 23 Roof components 24 Sealant 26a, 26b Work hole

Claims (3)

(57) [Claims] 1. A screw having a sharp end at the tip of the shank and a head at the tail end, wherein the shank has at least a first shank portion, a second shank portion, and a second shank portion extending from the sharp end toward the head. 3 shank parts are formed in sequence, a leading thread part is formed on the first shank part, a reamer part is formed on the second shank part, and a first thread thread and a second thread thread are formed on the third shank part. It is formed by forming a trailing screw portion that constitutes a thread, and the leading thread portion has a ridge diameter of D1 and a trough diameter of R1, the reamer portion has an outer diameter of d1, and the first thread of the trailing screw portion is formed. Thread diameter D
2 and the root diameter is R2, and the crest diameter of the second thread of the succeeding thread is d2, D1>d1> R1 and D2> d1
A screw which is> R2 and is formed such that d2 ≧ d1. 2. When the pitch of the preceding thread portion is P1 and the pitch of the first thread of the following thread portion is P2, P1 and P
請 characterized by comprising forming 2 to approximately P1 = P2
The screw according to claim 1 . 3. The shank comprises at least a first shank portion, a second shank portion, a third shank portion and a fourth shank portion, which extend from the sharp end toward the head, and the fourth shank portion is knurled on the peripheral surface. The screw according to claim 1 or 2 , which is formed by forming a work-hardened portion.