JPH0222174Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention relates to a core drill used for drilling holes in foamed concrete materials, new construction materials, composite wall materials, etc.

(Prior Art) Conventionally, core drills have been used to drill holes with relatively large diameters in foamed concrete materials, new building materials, composite wall materials, and the like.

This core drill has a structure in which a cylindrical body is provided on the outside of the center drill, and a cutting tip is provided on the edge of the cylindrical body.When drilling, the center drill secures the core, while the cylindrical body A cutting tip provided on the edge of the hole cuts the edge of the hole. Incidentally, the cutting tip is generally made of cemented carbide.

(Problem that the invention attempts to solve) When drilling with the above core drill, when the drilling is completed, the scraps (inner part of the hole) produced by the drilling
It was unavoidable that the liquid remained inside the cylindrical body.

Therefore, after completion of drilling, it is necessary to remove the scrap from the cylindrical body before the next drilling operation, which poses a problem in terms of work.

In order to remove the scraps, you will not only need appropriate tools such as spanners, wrenches, screwdrivers, or special tools prepared separately, but you will also need to remove the core drill itself from the motor, making it difficult to remove the scraps. This poses problems such as being troublesome and time-consuming, which impairs work efficiency.

(Means for solving the problem) Therefore, in this invention, the outside of the scraped part can be cut at the same time as the drilling operation, so that the scraped part falls under its own weight from the cylindrical body.

That is, the core drill of this invention is characterized in that, in the core drill as described above, a cutting tip is also drilled in the inner wall of the cylindrical body, and a cutting waste discharge hole is bored in the side wall of the cylindrical body. There is.

The number of cutting chips protruding from the inner wall of the cylindrical body may be one or more than two. In terms of cutting efficiency, it is best to use one piece, but considering the balance during rotation of the core drill, it was recognized that about three pieces can be used stably.

On the other hand, since the purpose of the cutting waste discharge hole is to discharge cutting waste generated by the cutting chip provided on the inner wall of the cylindrical body, it is preferable that the cutting waste discharge hole be provided adjacent to the cutting chip in the forward direction of rotation. . In addition, this cutting waste discharge hole is formed by providing a spiral groove on the outer wall of the cylindrical body, and when the spiral groove is connected to the spiral groove, the cutting waste discharged through the cutting waste discharge hole is further covered with the spiral groove. It can be efficiently guided to the outside of the perforation member.

(Function of the invention) According to the core drill of this invention, the hole edge is cut by the cutting tip provided on the edge of the cylindrical body, while the cutting tip protruding from the inner wall of the cylindrical body cuts the hole edge. The outer wall of the scrap remaining inside the cylindrical body is cut. Cutting waste generated by cutting the outer wall is discharged to the outside through a cutting waste discharge hole formed in the side wall of the cylindrical body.

As a result, when the core drill is turned downward after drilling is completed, the scraps remaining inside the cylindrical body can fall to the outside by their own weight.

(Example) Hereinafter, an example of this invention will be described with reference to the attached drawings.

As shown in FIGS. 1 and 2, a center drill 2 is connected to the shank 1, and via a flange 3 provided on the outside of the lower end of the shank 1,
A cylindrical body 4 is provided outside the center drill 2. This cylindrical body 4 has cutting chips 5 made of cemented carbide at predetermined intervals on the lower edge of the side wall 4a.
5 are fixed thereto, and cutting chips 6, 6 (for example, three equally spaced) made of cemented carbide are protruded from the inner side of the intermediate portion (the portion near the lower edge) of the side wall 4a.
Further, a cutting waste discharge hole 8 is bored in the side wall 4a of the cylindrical body 4 in front of the cutting chips 6, 6 in the direction of rotation (direction of arrow 7).
The cutting waste discharge hole 8 is continuous with a spiral groove 9 formed in the outer wall of the side wall 4a.

The figure shows a cutting waste discharge hole 8 and a spiral groove 9.
Although a case is shown in which the cutting tips 6 are provided in correspondence with one cutting tip 6 among the plurality of cutting tips, they may be provided in correspondence with a plurality of cutting tips 6, 6 individually.

FIG. 3 shows an object 10 to be drilled with the core drill of the embodiment.
This figure shows a state in which a hole 11 with a large diameter is drilled in a foamed concrete plate (for example, a foamed concrete board).

The center drill 2 drills the core hole 12, while the cutting chips 5, 5 fixed to the edge of the cylindrical body 4 cut the edge of the hole 11.

Further, the cutting chips 6, 6 bored inside the side wall of the cylindrical body 4 are connected to the inside part of the hole 11, that is, the cutting chips 13.
Cut the outer wall in the area where it will become. Cutting waste generated by this cutting is discharged to the outside of the side wall 4a through the cutting waste discharge hole 8, and further guided to the outside of the drilled object 10 along the spiral groove 9.

When the drilling of hole 11 is completed as described above,
The scraps 13 remain inside the cylindrical body 4. The outer diameter of this scrap 13 is made sufficiently smaller than the inner diameter of the cylindrical body 4 due to cutting by the cutting tips 6, 6, so the core drill is held facing downward to remove the scrap 13.
can be removed by falling under its own weight.

(Effects of the invention) As explained above, according to this invention, not only no tools are required to remove scraps from drilling, but also no special work is required, so the efficiency of drilling work can be improved. effective.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of this invention, FIG. 2 is a longitudinal sectional view of the embodiment, and FIG. 3 is a longitudinal sectional view of the embodiment in a state of use. 2... Center drill, 4... Cylindrical body,
5, 6... Cutting tip, 8... Cutting waste discharge hole, 9
...Spiral groove, 13...Removed scraps.

Claims (1)

[Claims for Utility Model Registration] 1. A core drill consisting of a center drill and a cylindrical body, in which a cutting tip is provided on the edge of the cylindrical body, the cutting tip also protruding from the inner wall of the cylindrical body, and A core drill characterized by a cutting waste discharge hole drilled in the side wall of the cylindrical body. 2. The core drill according to claim 1, wherein the number of cutting chips protruding from the inner wall of the cylindrical body is one or more. 3. The core drill according to claim 1, wherein the cutting waste discharge hole is provided adjacent to and in front of the cutting tip protruding from the inner wall of the cylindrical body in the rotational direction. 4. The core drill according to claim 1, wherein the cutting waste discharge hole is continuous with a spiral groove formed on the outer wall of the cylindrical body.