JPS5822612A - Hole drill - Google Patents

Abstract

PURPOSE:To cut smoothly the inner surface of a perforated hole of wood by a method wherein a ring cutter is fixed to the tip of a chiesel edge part and the chiesel edge part is inclined in a centripetal direction. CONSTITUTION:A drill (straight shank drill) body 1 has a point 1a and chiesel edges 1b on the cutting part and besides a ring cutter (hole saw) 2 is caped by a screw 3 on the tip of the cutting part. The ring cutter 2 is nearly cylindrical, cutting edges 2a in the form of this cutter is formed on the tip part and the end of each chiesel edge is inclined 2b in the inward or centripetal direction. Marking operation is carried out by the cutting edges 2a of the ring cutter 2 and the inside of the hole is finished smoothly.

Description

[Detailed description of the invention] The present invention relates to a hole drill.

A hole drill, which is mainly used for drilling holes in wood, has a cutting edge consisting of an awl A, a cutting blade, and a cutting edge C formed on the outer edge of the cutting blade, as shown in Figure 1. .

This hole drill is used when drilling through holes in boards and columns.
Although there is no particular problem outside the fish body where the inner surface of the hole is generally rough, there are cases where a semicircular groove d is formed on the end surface of the plate, or another hole f is bored perpendicular to one hole θ. In some cases, it often causes problems. For example, when forming a semicircular groove on the wood end surface of a board, use the tip of the drill half a turn to make the cutting edge C.
The cake groove is cut using the following steps, and the bottom of the hole is cut to make it flat in the next half turn. At this time, since the drill d is idling, it does not perform its original function of positioning, and the cutting direction gradually deviates due to the difference in cutting stress, drilling an accurate groove in the same direction as the drill axis. It is not possible.

Also, when drilling two long holes perpendicularly,
When drilling one long hole into the other, if the hole penetrates into the other side, the drill will often shake and the axis of the hole will be misaligned.

The present invention eliminates such conventional disadvantages, and
This is an attempt to provide a hole drill that is capable of finely cutting the inner surface of a hole, and the gist is that a ring cutter is attached to the tip of the drill blade, and the blade is inclined in the centripetal direction. .

Hereinafter, the present invention will be explained with reference to the illustrated embodiment. L is a drill (straight shank drill) main body, which has a drill bit 1a and a cutting blade 1b at the blade part, and a ring cutter (hole ring) 2 at the tip of the blade part. is adhered with Inno3 stopper. This ring cutter 2 has a cylindrical shape and has a serrated blade 2a formed at its tip, and the end face of the sword is inclined 2b inward, that is, in the centripetal direction. When drilling with the drill according to the present invention configured as described above, a cutting action is performed by the tip of the blade 2a of the ring cutter 2, and the ring cutter 2 cuts the hole into a ring shape with a width approximately equal to the thickness of the ring cutter. Therefore, the ring cutter 2 is in a biting state, and while this state is maintained, the cutting blade 1b chases and cuts the inner part surrounded by the ring cutter 2. For this reason, the center of the cutting hole is cone 1
Since the peripheral edge of the hole is held by the ring cutter 2, the drilling operation is performed extremely stably, and eccentricity of the shaft of the drill is prevented. Therefore, even when forming semicircular grooves on the wood end surface as described above, or when forming mutually orthogonal through holes, eccentricity can be prevented by the holding force of the ring cutter's peripheral edge of the hole. and can perform the correct cutting process.

In addition, in the case of a conventional drill, the inner surface of the hole is scratched by the cutting blade, resulting in a rough and rough surface, but in the case of the drill according to the present invention, the surface cut by the ring cutter 2 This results in a clean, smooth finish and eliminates the need for subsequent finishing. Furthermore, in the case of the present invention, since cutting is performed with both the cutting blade and the ring cutter 2,
Cutting efficiency is improved and workability is high.

As is clear from the above description, the hole drill according to the present invention can be used not only for ordinary drilling, but also for cutting semicircular grooves on the end surface of wood or drilling multiple holes that intersect with each other. The drill can work accurately without wobbling during cutting, and has excellent effects such as high efficiency and a beautiful finished cutting surface.

[Brief explanation of drawings]

Figure 1 shows a conventional example: (a) is an external view of the tip of the drill, (b) is an explanatory diagram of its cutting state, and (c) is a semicircular groove formed on the end surface of the wood, which is perpendicular to each other. 2 shows a drill according to the present invention, (A) is an external view of the tip, (B) is a front view thereof, and FIG. 3 is a cross section of the ring cutter. FIG. 4 is an explanatory diagram of the cutting state. 1...Drill body 2...Ring cutter 2a...Blade 2b...Inclination 3...Screw Patent applicant Nippon Gakki Manufacturing Co., Ltd. No. 1v ! J (a) @2 rri

Claims (2)

[Claims] (1) A hole drill characterized by having a ring cutter attached to the tip of the blade of a straight shank drill. (2) The hole drill according to claim 1, wherein the blade portion of the ring cutter is inclined in a centripetal direction.