JP4684158B2 - Chopped self-drilling screw for fastening plasterboard - Google Patents

Description

The present invention is related to paddy cutting, self-drilling screws for fastening a gypsum board to a substrate.

  There are two types of self-drilling screws: a chopping type with a sharp tip and a drill type with a drill part with a cutting edge at the tip. The former type of chopped screw makes the shaft enter the member by expanding the structure of the member (work) at the tapered portion with the sharpened tip, and the base material made of soft material such as wood For example, it is frequently used to fasten various workpieces to a thin steel plate substrate having a plate thickness of about 0.5 to 1.2 mm.

  Various improvements have been made to chopped self-drilling screws. For example, two threads are formed on the shaft, and various development examples have been proposed based on the two-thread system. For example, a portion of the shaft excluding the tapered portion is formed in a straight shape having a constant valley diameter over the entire length, and the heights of the two threads are made different from each other.

  On the other hand, in Patent Document 1, in which the entire thread portion is composed of two threads, the height (or outer diameter) of both threads is the same in a certain range on the head side of the thread portion. It is described that it is formed with the same high portion, and a portion of the screw thread on the tip side of the high height portion is formed with a different height portion where the heights of both screw threads are different.

Further, in Patent Document 2, when the entire thread portion is formed of two threads, the thread portion is divided into a small-diameter parallel thread portion located on the distal end side and a large-diameter parallel thread portion located on the head side. And a tapered intermediate threaded portion that smoothly connects the small-diameter parallel threaded portion and the large-diameter parallel threaded portion.
JP 2001-200222 A Japanese Patent No. 3334563

  Self-drilling screws are used in various applications, and one of the applications is to fasten a gypsum board constituting a wall or ceiling of a building to a frame material. Conventionally, wood has been widely used as a frame material (base material) constituting walls and ceilings. However, in recent years, in order to improve fire resistance and durability, for example, a thickness of about 0.5 to 1.2 mm and a cross section of about C A thin steel plate frame material (underlying material) formed in a letter shape is often used.

  In any case, the work is fastened by the screw thread biting into the base material. If the outer diameter of the tip side portion is formed in a tapered shape as in Patent Document 2, the work enters the base material. Can be said to be easy.

  By the way, when two threads are formed, the lead angle of each thread can be increased, so that the length of the screw that advances per rotation can be increased, and there is an advantage that the working efficiency can be improved. However, in the case where two threads are set to the same height in each part as in Patent Document 2, if the height of the thread becomes high, the screwing resistance becomes too large, and if the height of the thread is made low, the base material There is a problem that the hooking resistance becomes small and the fastening strength becomes weak.

This invention is made | formed in view of such a present condition, and makes it a subject to provide the chopping type self-drilling screw for gypsum board fastening of the improved form.

A grated cutting self-drilling screw for fastening a gypsum board according to the present invention comprises: a shaft having a circular cross section and a head provided at the base end thereof, and the tip of the shaft opposite the head is the has become a tapered-off portion a pointed tip, the shaft, while the threaded portion having a double-threaded screw thread to start the destination Subomari portion is formed, on said head, driver It has a basic configuration that an engagement hole into which a bit fits is formed.

The portion of the threaded portion excluding the tapered portion is a smooth portion of the large diameter portion located on the head side, the small diameter portion located on the distal end side, and the large diameter portion and the small diameter portion. The valley of the large diameter portion and the valley of the small diameter portion are each in a straight shape with a substantially constant outer diameter, and the valley diameter of the large diameter portion is the small diameter portion. On the other hand, the two thread threads are different in height from each other in each of the portions, and the outer diameters of the large diameter portion and the small diameter portion are substantially the same. It has a constant straight shape, and the angle of the high thread is smaller than the angle of the low thread.

Furthermore, before Symbol head is formed in a trumpet shape with a curved surface profile which is curved in longitudinal section view with an outer diameter gradually enlarged toward the top surface, and an outer peripheral edge of the trumpet-shaped portion is set forms a flange portion thickness equal to dimensions greater than twice the maximum outer diameter of the flange portion sleep Flip part in.

As described above, in the self-drilling screw, if the thread portion is configured as a double thread, the lead angle of the thread can be increased, so that the screwing operation can be performed quickly.

And in this invention, while the front end side is small diameter among screw parts, while the initial approach to a workpiece | work and a base material is made easy, and the head side is large diameter, it is a screw thread to a base material. It is possible to obtain a high fastening strength by firmly biting, and furthermore, since the two thread threads have different heights in each part, the high thread threads are firmly bitten into the base material. It is possible to suppress the screwing resistance from becoming excessively high.

In summary, the self-drilling screw of the present invention can improve the fastening strength and reduce the labor required for the fastening operation while maintaining the advantage of the double thread screw that can perform the fastening operation efficiently.

Now, gypsum board is often used as an interior material for buildings mainly in houses, but in recent years, gypsum board tends to be reduced in strength because it often contains waste materials. In this regard, if the head is configured as in the present invention , the head has a flange portion, and the outer diameter of the flange portion is larger than twice the maximum outer diameter of the screw portion (external to the head of the conventional screw). diameter is substantially because it is twice the outside diameter of the threaded portion) is coupled with improved holding force against the workpiece, particularly suitable to conclude the brittle gypsum board than traditional.

Next, it described based on the embodiment of the present invention with reference to the drawings.

(1). Structure of the First Embodiment In FIG. 1, (A) is a front view of a self-drilling screw, (B) is a front view in a state where a screw thread is omitted, (C) is a plan view, and (D). FIG. 4 is a partial cross-sectional view. In (D), the parallel diagonal lines (hatching) of the cross-sectional display are only partially displayed.

  The self-drilling screw includes a shaft 1 having a circular cross section and a head 2 integrally connected to the base end thereof, and the tip of the shaft 1 opposite to the head 2 has a pointed tip. It is a narrowed portion 3. The taper angle of the tapered portion 3 is set to about 25 degrees. In addition, although the tapered portion 3 of the present embodiment is formed in a conical shape, it can be formed in a bullet shape having a curved shape in a longitudinal sectional view.

Two threads of the first thread 4 and the second thread 5 are formed on the shaft 1, and a flat valley is exposed between the adjacent threads 4 and 5 in a sectional view. is doing. Both screw threads 4 and 5 start (rise) from the constricted portion 3, and both screw threads 4 and 5 extend to the vicinity of the neck (the end of the screw threads 4 and 5 and the head 2 There may be unthreaded parts in between . And the height of the 1st thread 4 is higher than the height of the 2nd thread 5 in each site | part except the start end and the termination | terminus.

In the present embodiment, the starting end (tip) of the first screw thread 4 extends to the tip of the tapered portion 3, and the starting end of the first screw thread is the chopped portion 4 a. By the biting action of the chopping portion 4a, an opportunity for the shaft 1 to enter the member ( gypsum board , base material) is created. The terminal portions of both the first screw thread 4 and the second screw thread 5 are gradually lowered in height, and the terminal ends of the second screw threads 5 are located at the back surface in FIG.

  Of the threaded portion in which the two threads 4 and 5 are formed, the portion excluding the tapered portion 3 is a large-diameter portion 6 located on the head 2 side and a small-diameter portion 7 located on the tip side. And the taper portion 8 that smoothly connects both the large diameter portion 6 and the small diameter portion 7. It has a straight shape with a constant outer diameter.

  That is, the valley diameter D1 of the large diameter portion 6 is substantially constant over the entire length of the large diameter portion 6, and the outer diameter D2 of the first thread 4 and the outer diameter D3 of the second thread 5 in the large diameter section 6 are Except for the terminal end, each is substantially constant over the entire length of the large-diameter portion 6. Similarly, the valley diameter D 4 of the small-diameter portion 7 is substantially constant over the entire length of the small-diameter portion 7. The outer diameter D5 of the mountain 4 and the outer diameter D6 of the second screw thread 5 are substantially constant over the entire length of the small diameter portion 7, respectively.

  The outer diameter difference (D2-D5) of the first thread 4 and the outer diameter difference (D3-D6) of the second thread 5 are substantially the same as the difference in valley diameter (D1-D4). In the present embodiment, the height of the first thread 4 is set to about twice the height of the second thread 5 in both the large-diameter portion 6 and the small-diameter portion 7, but the ratio of the height is arbitrary. Can be set. It is also possible to set the outer diameter D5 of the first screw thread 4 in the small diameter portion 7 to the same extent as the outer diameter D3 of the second screw thread 5 in the large diameter portion 6.

  In the present embodiment, θ1 is set to about 30 degrees and θ2 is set to about 60 degrees, but of course, the angle can be arbitrarily set as necessary.

The head 2 has a trumpet shape having a profile curved outwardly concave, and a cross hole 9 is formed on the top surface as an example of an engagement hole into which a driver bit is fitted. A flange portion 2a is provided at the upper end. The outer diameter of the flange portion 2a is set to about three times the outer diameter D2 of the first thread 4 in the large diameter portion 6.

(2) Usage state Fig. 2 shows an example of the use of screws. In this example, the gypsum board 10 is used for fastening to a frame material ( base material: base material) 11 made of a thin steel plate and having a substantially C-shaped cross section, and (A) is a sectional view in a screwed state. (B) is sectional drawing in the middle of screwing. A cover 12 is attached to the surface of the gypsum board 10 and a backing paper 13 is attached to the back.

  In screwing in the screw, the small diameter portion 7 first enters the frame material 11 from the gypsum board 10, and then the large diameter portion 6 enters the gypsum board 10 and the frame material 11. In the screwed state, the threads 4 and 5 of the large-diameter portion 6 are hooked on the inner peripheral edge of the frame member 12, and the flange portion 2b of the head portion 2 is in a state of being recessed into the gypsum board 10 (on the cover sheet 12). To put wallpaper.)

  The frame member 11 is formed with a burring-like bulging portion 11a protruding in the screwing direction by the screw entry, and the bulging portion 11a is caught by the flank (following flank) of the screw threads 4 and 5 to be screwed. Omission is prevented.

  In the present invention, since the small diameter portion 7 first enters the frame member 11, the screwing resistance from the initial stage to the middle stage of the screwing is small and the screwing can be smoothly performed. (Ie, the frame material 11 is pushed and spread), there is no backlash between the large diameter portion 6 and the frame material 11, and the threads 4 and 5 are formed in the bulging portion 11 a of the frame material 11. It can be hooked firmly, and thereby a high fastening strength can be ensured.

  As in this embodiment, when the flange portion 2a of the head 2 is set to about 3 times the maximum diameter (nominal diameter) D2 of the screw thread (the conventional product is about 2 times), the pressing force against the gypsum boat 2 is increased. Although it can be remarkably improved, since it is necessary to squeeze the flange portion 2a into the gypsum board 10, if the outer diameter of the flange portion 2a is larger than before, a high pulling resistance is required at the end of screwing. For this, the hooking resistance of the frame member 11 to the threads 4 and 5 must be large.

In this regard, in the present invention, as described above, since the hooking resistance of the frame member 11 with respect to the threads 4 and 5 of the large-diameter portion 6 increases, the bulging portion 11a of the frame member 11 is crushed and the screw is idle. (screw phenomenon Do that to fool) while avoiding the whole of the head 2 can be sink into the interior of the gypsum board 10.

  In addition, if the entire screw portion is straight, the gypsum board may collapse and play may occur between the screw portion. However, in the present invention, the large diameter portion 6 bites into the gypsum boat 10 as well. The thread portion can be brought into close contact with the tissue of the gypsum board 10.

Needless to say, the screw of the present embodiment can also be used to fasten the gypsum board 10 to a wooden frame material (base material) . In this case, the whole or most of the threaded portion remains in the frame material in many cases. However, since the screwing resistance as a whole is reduced by the presence of the small diameter portion 7, the burden on the operator during the fastening work is reduced. can do.

The present invention can in addition to ingredients body of even the above embodiment.

Form of engagement hole in the head Ri Nodea not limited to cross-hole, four square hole and hexagonal hole, or a star-shaped hole of, can be adopted engagement holes of various shapes.

A diagram showing a structure of implementation form is the (A) is a front view, (B) is a front view of a state omitting the thread, (C) is a plan view, (D) is a partial cross-sectional view . It is sectional drawing which shows a use condition.

As an example of uniaxial 2 head 3 destination Subomari unit 4 first screw thread 5 second threads 6 large-diameter portion 7 cross recess 10 stone as an example of the small diameter portion 8 tapered portion 9 engages hole plaster board 11 substrate Thin steel frame material (base material)

Claims (1)

A chopped self-drilling screw for fastening a gypsum board to a substrate,
A shaft having a circular cross section and a head provided at the base end thereof, and the tip of the shaft on the side opposite to the head is a tapered portion sharpened at the tip, while threaded portion having a double-threaded screw thread to start the destination Subomari portion is formed, wherein the head portion forms a engaging hole driver bit is fitted,
In the configuration
Of the threaded portion, the portion excluding the tapered portion is smoothly connected to the large-diameter portion located on the head side, the small-diameter portion located on the distal end side, and the large-diameter portion and the small-diameter portion. The taper part
The trough of the large diameter portion and the trough of the small diameter portion are each in a straight shape with a substantially constant outer diameter, and the trough diameter of the large diameter portion is set larger than the trough diameter of the small diameter portion. While
The two thread threads are different in height from each other in the respective parts, and the large diameter part and the small diameter part are each in a straight shape having a substantially constant outer diameter. The high thread angle is smaller than the low thread angle,
Further, the head is formed in a trumpet shape having a curved profile that is curved in a longitudinal sectional view while the outer diameter gradually increases toward the top surface, and is formed on the outer periphery of the trumpet-shaped portion. Form a flange portion having the same thickness, and the flange portion is set to a size larger than twice the maximum outer diameter of the screw portion.
A chopped self-drilling screw for fastening plasterboard .

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