JPH0512730U - Screw with drill blade - Google Patents

Abstract

(57) [Summary] [Purpose] To enable screws with drill blades to be efficiently screwed in with low thrust. [Structure] A first blade tip 15 and a second blade tip 16 following the first blade tip 15 are provided at the tip of the screw shaft 13, and the drill angle of the second blade tip is set to be smaller than the drill angle of the first blade tip 15. By providing the holes in two stages, it is possible to reduce the thrust at the time of screwing.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a screw with a drill blade, and more particularly to a tapping screw with a drill blade used for attaching an outer wall to a lightweight steel of steel frame construction.

[0002]

[Prior Art]

 As shown in Fig. 5, the conventional tapping screw used to attach the outer wall to the light-weight steel has a drill with an outer diameter equal to that of the shaft of the screw shaft 1 as shown in Fig. 5. When the tapping screw is screwed in, the drill blade 2 penetrates the outer wall 4 to make a pilot hole in the lightweight steel 3, and then the screw shaft 1 is screwed into the pilot hole. The groove is screwed in while carving, and the outer wall is pressed down and fixed by the head.

[0003]

[Problems to be solved by the device]

 By the way, the resistance at the time of drilling the pilot hole for screwing in the tapping screw as described above is proportional to the diameter of the drill blade, and the larger the shaft diameter, the larger the screwing thrust required. Since the outer diameter of the shank of No. 1 and the outer diameter of the drill blade 2 are almost equal, the diameter of the drill blade 2 is large, and in the case of a large size such as a tapping screw with a diameter of 6 mm, a large thrust force must be applied when screwing in. The problem is that it is also inefficient.

Further, the tapping screw is often screwed in at a high place, and it is dangerous to screw it in by applying a large thrust, and a large thrust is applied when screwing it into a place higher than the operator's head. However, there is a problem that it is difficult to perform the fastening work.

[0007] Therefore, the present invention is a screw with a drill blade that generates less resistance when drilling a pilot hole, can be screwed with a low thrust even in a thick size, and can perform fastening work efficiently at any place. The challenge is to provide.

[0006]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention provides a drill blade provided at the tip of a screw shaft with a first blade tip at the tip and a second blade tip following the first blade tip, and a drill angle at the first blade tip. In contrast to this, a configuration in which the drill angle of the second cutting edge is set small is adopted.

[0007]

[Action]

 When screwed into the light-weight steel, first the first cutting edge at the tip pierces, then the second cutting edge expands the above-mentioned piercing to form a pilot hole having a diameter corresponding to the screw shaft, and then the screw The shaft enters while making a thread groove in the pilot hole. When forming the pilot hole, the first cutting edge at the tip is small and thin, so there is less resistance and the biting effect is enhanced. Next, the second cutting edge is set to have a smaller angle than the first cutting edge. Since it is carried out while scraping around the perforation, the pilot hole can be formed with low thrust, and the efficiency of the fastening work can be improved.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to the accompanying drawings. As shown in FIGS. 1 to 4, the screw 11 with a drill blade is provided with a drill blade 14 for drilling at the tip of a screw shaft 13 having a head 12, and the drill blade 14 has a first cutting edge 15 at the tip. It is formed by the second cutting edge 16 following this, and has a structure in which the drill angle A of the first cutting edge 15 at the tip and the drill angle B of the second cutting edge 16 are set to different angles. The drill angle B of the second cutting edge 16 is set smaller than the drill angle A of.

The screw shaft 13 is formed by providing a screw 13b on the outer circumference of a circular shaft 13a, and its diameter and axial length depend on the conditions such as the outer wall 4 fixed to the lightweight steel 11, for example. The head 12 is illustrated as a hexagon with a collar as an example, but a shape or structure having a driver engaging groove such as a circular shape or a truncated cone shape may be adopted.

The drill blade 14 provided at the tip of the screw shaft 13 is provided with notches 17 on the outer surfaces on both sides of the axis, and the side edge of the notch 17 is located rearward in the screw turning direction of the screw with the drill blade. Is the cutting edge 18.

The drill angle A of the first cutting edge 15 is 120 ° ± 5 °, which is set to an optimum angle with a high biting effect on the lightweight steel 3, and the second cutting edge 16 has the same cutting angle. The drill angle B may be smaller than the drill angle A of the first cutting edge 15, and a preferable angle is, as will be described later, more acute than 90 °.

The first cutting edge 15 has a small diameter and is thinly formed in the axial direction, and the second cutting edge 16 is formed so as to start from an outer peripheral portion of the first cutting edge 15 and have a conical shape in the axial direction. It

The drill blade screw of the present invention is configured as described above, and applies the thrust and rotation to the drill blade screw 11 by pressing the first blade tip 15 from the outer wall 4 toward the lightweight die steel 3. First, the first blade edge 15 penetrating the outer wall 4 bites into the lightweight steel 3 to form a small-diameter pilot hole, and then the second blade edge 16 scrapes off the periphery of the small-diameter pilot hole to form a large-diameter pilot hole. Form.

As described above, the cutting resistance generated when the pilot hole is formed by the screw 11 with a drill blade is proportional to the diameter of the drill blade 14, but since the first blade tip 15 has a small diameter and is thinly formed, The cutting resistance of the second cutting edge 16 is smaller than that of the first cutting edge 15 and the second cutting edge 16 has a sharper angle than the first cutting edge 15. Therefore, the cutting resistance is small in this case as well. The pilot hole can be formed with low thrust, and even a thick drill screw can be screwed in smoothly.

When the screw 11 with the drill blade is screwed in, the drill blade 2 has the same diameter as the screw shaft 1 and the drill angle is set to 120 ° as in the conventional case shown in FIG. Since the biting amount of the drill blade with respect to the blade is large, and a large area must be cut before the drill blade 2 penetrates, a large resistance is generated and a large thrust force is required.

On the other hand, when the drill blade 14 is formed by the first blade edge 15 and the second blade edge 16 following the first blade edge 15 and the first blade edge 15 has a small diameter and is thin, the biting amount with respect to the lightweight die steel 3 is small. Therefore, the generation of cutting resistance is reduced, and the first cutting edge 15 and the second cutting edge 16 can smoothly penetrate the lightweight steel 3 with a low thrust to form a pilot hole.

As described above, when the first cutting edge 15 and the second cutting edge 16 penetrate the lightweight die steel 3, the screw shaft 13 then enters the pilot hole, and the screw 13b forms a thread groove around the pilot hole. The outer wall 4 can be clamped and fixed by the head 12 after being formed and screwed.

[0018]

【effect】

 As described above, according to this invention, the first cutting edge and the second cutting edge are provided in series at the tip of the screw shaft, and the drill angle of the second cutting edge is set smaller than that of the first cutting edge. Holes can be drilled in two stages, and even thick screw screws can be screwed in with low thrust, enabling smooth fastening work even in high places. Further, the screwing work can be shortened, and the work efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a front view of a screw with a drill blade according to the present invention.

[Fig. 2] Bottom view of the above

FIG. 3 is an enlarged view of the drill blade.

FIG. 4 is an explanatory view showing an initial state of formation of a pilot hole in the above.

FIG. 5 is an explanatory diagram showing conventional hole cutting of a screw with a drill blade.

[Explanation of symbols]

 11 Screw with Drill Blade 12 Head 13 Screw 14 Drill Blade 15 First Blade Edge 16 Second Blade Edge A, B Drill Angle

Claims (2)

[Scope of utility model registration request] 1. A drill blade provided at a tip of a screw shaft is formed by a first blade tip at a tip and a second blade tip following the first blade tip, and a drill having a second blade tip with respect to a drill angle of the first blade tip. Screw with a drill blade that has a small angle. 2. The screw with a drill blade according to claim 1, wherein the drill angle of the first cutting edge is 120 ° ± 5 °, and the drill angle of the second cutting edge is smaller than the drill angle of the first cutting edge. Set screw with drill blade.