JPH025922Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a woodworking drilling awl that is used in conjunction with an electric motor.

[Prior art]

The inventor of this device had previously registered a utility model.
In the invention of No. 548834, we proposed a drilling awl for woodworking that allows the diameter of the hole to be changed with a single awl.

This drilling cone has a dovetail groove cut horizontally at the bottom of one side of the main body of the cone, with a gentle vertical inclination, and the upper wall of the dovetail groove is vertically cut continuously upward from the bottom of the dovetail groove. It is formed on the lower end edge of the push plate formed by the split groove, a horizontal scooping blade is provided at the lower end of the main body, a small guiding cone is provided at the rotation center, and a plate-shaped perforating blade is provided in the dovetail groove. It is movably inserted and fixed with a fixing screw attached to the push plate part, and a scooping blade is provided on the lower edge of the surface of the perforating blade, and a sharp cutting edge is provided on the lower surface of the inclined lower end of the perforating blade. It has a configuration in which a claw-shaped cutting blade for cutting the tip around the hole is connected to the scooping blade and protrudes downward.

When drilling with this drilling awl, the small guiding cone provided at the lower end of the main body is screwed into the wood surface to be drilled, and the claw-shaped cutting edge of the drilling blade cuts a cutting line around the hole. The wood surface on the inside of the line is cut with the scooping blade of the punching blade, and the central part is cut with the scooping blade at the lower end of the main body, thereby making a hole of the planned diameter.

With this perforation drill, the diameter of the perforation can be changed in various ways by moving the perforation blade relative to the main body by loosening and tightening the fixing screws on the push plate, and the perforation blade can be replaced. Although this drill bit is easy to make and very convenient to handle, it was designed as a drill bit that rotates manually and has a slow rotation speed.

[The problem that the idea attempts to solve]

By the way, considering the shape of the drilling blade of the drilling awl with the above-mentioned configuration, a claw-shaped cutting blade is located in front of the scooping blade provided on the lower edge of the surface of the drilling blade and cuts around the hole first. It is not possible to provide a cutting edge around the hole, and the cutting blade for cutting around the hole is provided on the lower surface of the inclined lower end of the punching blade, and its cutting edge is continuous with the scooping blade edge, and is located at the rear of the scooping blade. It is something to do.

Therefore, when drilling, due to the positional relationship between the scooping blade and the cutting blade, cutting by the scooping blade will not start unless the claw-shaped cutting blade bites (cuts) into the wood surface to its base. When this drilling drill is attached to an electric motor and used under high-speed rotation, frictional heat is generated at the cutting edge, which is constantly biting into the wood surface all the way to the base, and this heat is transferred to the cage and immediately burns it. Not only does it cause
High-temperature frictional heat has the disadvantage of causing a tempering phenomenon on the cutting edge and deteriorating its sharpness.

This invention was developed in consideration of the above points, and it is an electric drill for woodworking that can be used under high-speed rotation by an electric motor, and can easily and quickly perform drilling to increase work efficiency. The purpose is to provide.

[Means to solve the problem]

The gist of this invention to achieve the above purpose is that a movable plate-shaped perforating blade is installed in a dovetail groove that is horizontally and gently inclined in the vertical direction at the bottom of one side of the main body of the cone. In the woodworking drill which is fitted and fixed, a horizontal scooping blade is provided at the lower end of the main body substantially perpendicular to the drilling blade, and a claw-shaped cutting blade is provided in front of the scooping blade corresponding to the outer end of the scooping blade. and a small guiding cone directed downward at the center of rotation of the main body, and the perforating blade has a scooping blade on the lower edge of the surface thereof, and a scooping blade protruding downward from the lower surface of the inclined lower end of the perforating blade. This electric drill for woodworking is characterized by being equipped with a chisel blade body and having a variable hole diameter.

[Effect]

According to this invention constructed as described above, the small guiding cone provided at the lower end of the main body is inserted into the wood surface to be drilled, and the chisel blade provided on the lower surface of the inclined lower end of the drilling blade is activated. , cut a narrow groove around the hole. At approximately the same time that the end of the scooping blade provided on the lower edge of the surface of the perforating blade starts cutting, the inner wood surface of this thin groove is cut by a claw-shaped cutting blade provided on the main body against the wood surface. A dividing score line is cut by. Then, the horizontal scooping blade installed at the lower end of the main body cuts the wood surface inside the split score line immediately after cutting the split score line, and the wood surface outside the split score line first starts cutting near the narrow groove. As the cutting progresses with the scooping blade of the drilling blade, the hole is cut diagonally.

〔Example〕

Hereinafter, embodiments of this invention will be described with reference to the drawings.

A dovetail groove part 6 is cut in the lower part of one side of the main body part 1 of the cone A in a horizontal direction and is gently inclined in the vertical direction.

The upper wall of the dovetail groove part 6 is separated from the main body part 1 side by a vertical groove 3 cut upward continuously from the bottom of the dovetail groove part, and is formed on the lower edge of the push plate part 2 connected at the upper part of the main body part 1. Then, a plate-shaped perforating blade 7 is movably inserted into the dovetail groove 6, and the perforating blade 7 is fixed with a fixing screw 9 provided on the push plate 2.

At the lower end of the main body 1 adjacent to the dovetail groove 6, there are provided a horizontal scooping blade 4 substantially orthogonal to the perforating blade 7, a guiding small cone 5 directed downward from the center of rotation, and a scooping blade 4 extending downward from the center of rotation. A claw-shaped cutting blade 4a is provided corresponding to the outer end and positioned in front of the scooping blade 4 to cut into the dividing cutting line.

The punching blade 7 has a scale 8 engraved on its upper surface to indicate the diameter of the hole, the lower surface is curved forward as a whole and has a protruding shape, and a scooping blade 1 is provided on the lower edge of the surface.
0, and a chisel blade 11 for cutting a narrow groove around the hole is provided on the lower surface of the inclined lower end of the drilling blade 7 to protrude downward. The width of the chisel blade 12 of this chisel blade body 11 is suitably about 2 to 3 mm.

In addition, 13 in the figure is a reference line engraved on the pressing plate portion corresponding to the scale 8 of the punching blade 7.

In the above configuration, to adjust the drilling blade 7 to match the diameter of the hole to be drilled, loosen the fixing screw 9, move the drilling blade 7 based on the scale 8 and reference line 13, and tighten the fixing screw 9. Tighten and secure.

In the drilling operation, a small guiding cone 5 provided at the center of rotation at the lower end of the main body pierces the center of the hole in the wood surface and a chisel blade protrudes from the lower surface of the inclined lower end of the drilling blade 7 midway through the screwing process. A narrow groove is cut around the hole by the chisel blade 12 of the body 11.

Cutting of the wood surface by the scooping blade 10 of the perforating blade 7 starts near the narrow groove when the depth of the narrow groove by the chisel blade 11 increases. The claw-shaped cutting blade 4a starts cutting into the wood surface, and a dividing cutting line is cut.
The wood surface inside the dividing score line is cut immediately after the dividing score line is cut by the scooping blade 4 of the main body part 1.

Cutting from the vicinity of the narrow groove by the scooping blade 10 of the punching blade 7 eventually reaches the dividing score line portion and becomes a diagonal cut.

〔effect〕

According to this invention configured as described above, the following effects are achieved.

(1) With the guiding small cone at the lower end of the main body of the cone screwed into the wood surface to be drilled and holding the center, first rotate the lower surface of the inclined lower end of the drilling blade around the hole to be drilled. Since the chisel blade of the chisel blade provided in the chisel blade body cuts a narrow groove corresponding to the blade width, even if it is attached to an electric motor and used under high speed rotation, there will be no claw-shaped grooves around the hole at all times like in the past. It can withstand long-term use without generating frictional heat or the like when cutting a wood surface with the cutting blade biting into its base.

(2) The inner wood surface of the thin groove is cut with a dividing score line so as to concentrically divide into two parts using a claw-like cutting blade provided at the lower end of the main body. Cut with a scooping blade,
The outer wood surface is perforated by cutting diagonally from the narrow groove side with the scooping blade of the perforating blade, which has a gently sloped shape, changing the cutting method, so the perforation diameter can be freely adjusted to create a large diameter. Even when drilling a hole, it bites into the wood surface well, extremely reducing cutting resistance, and always maintains a sharp edge to perform the drilling work smoothly and quickly.

[Brief explanation of drawings]

Figure 1 is a front view of this invention, Figure 2 is a side view,
3 is a bottom view, FIG. 4 is a perspective view of essential parts, FIG. 5 is a front view of the punching blade, and FIG. 6 is a bottom view of the same. 1...Main part, 2...Press plate part, 3...Vertical groove,
4... scooping blade, 5... small cone, 6... dovetail groove, 7
...Drilling blade, 8...Scale, 9...Fixing screw,
10... scooping blade, 11... chisel blade body, 12... chisel blade, 13... reference line.

Claims (1)

[Scope of utility model registration request] In a woodworking awl in which a movable plate-shaped drilling blade is inserted and fixed into a dovetail groove provided laterally and gently inclined in the vertical direction at the lower end of one side of the main body of the cone, the lower end of the main body includes: A horizontal scooping blade substantially perpendicular to the punching blade, a claw-shaped cutting blade in front of the scooping blade corresponding to the outer end of the scooping blade, and a small cone for guiding downward at the center of rotation of the main body. and the perforating blade body is provided with:
An electric drill for woodworking with a variable drilling diameter, characterized in that a scooping blade is provided on the lower edge of the surface, and a chisel blade protrudes downward from the lower surface of the inclined lower end of the drilling blade.