JPS597048Y2 - Large diameter woodworking drill - Google Patents

Description

[Detailed description of the invention] This invention is for drilling large-diameter holes such as counterbore drills, hole saws, and free drills for drilling door lock mounting holes, double holes, etc. This invention relates to a woodworking drill which is composed of a center drill for drilling a center hole and a large diameter drill.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The large-diameter woodworking awl of the present invention will be described below with reference to the attached drawings, which are examples thereof.

The center drill 1 includes one equipped with an induction screw 4 as shown in Fig. 1, and one that cuts directly as shown in Fig. 2, but in both cases, the depth of cut (cutting speed) is adjusted to match the diameter of the drill bit. It is set as.

However, if the drill bit 2 has a larger diameter than the center drill 1, for example, the
When the counterbore drill shown in the figure or the hole saw shown in FIG. 2 are attached, there is a drawback that the cutting speed and depth of cut of the large diameter drill 2 are not compatible.

In other words, when drilling a double hole with the counterbore drill shown in FIG. 1, the amount of cut (feed amount) by the induction screw 4 becomes too large, resulting in an overload condition.

Furthermore, when drilling a large diameter through hole such as a door lock mounting hole, the hole will not cut in unless it is pressed very strongly by hand.

This also applies to the hole saw shown in FIG.

Therefore, the present invention has a large diameter cone 2 on the outer surface of the center drill 1.
By providing a guide screw 3 with a pitch suitable for the depth of cut, the amount of feed is always constant, and the large diameter drill does not cut too far and become unable to rotate due to overload, and there is no need to press forcefully by hand. It is.

The guide screw 3 is installed at the top of the center drill 1;
That is, it should be placed immediately before the large-diameter drill 2 or slightly above the cutting edge 5 of the cutting blade in the case of hole saws, free drills, etc., as shown in Figure 2, so that it can fit into the hole in the workpiece drilled by the center drill. do.

The center drill 1 normally has the largest diameter D1 at the tip, and the diameter D2 becomes slightly smaller toward the top to ensure smooth rotation.

Therefore, the thread diameter D3 of the guide screw should be approximately equal to or slightly larger than the diameter D1 of the tip portion, and should not be too large.

Even if the diameter is approximately the same, it can sufficiently function as a guide screw due to the natural expansion of the material to be cut after drilling, the deflection of the center drill, etc., and does not create an unnecessarily large resistance.

In other words, D3≧D1. The pitch P of the guide screw 3 may be changed as appropriate depending on the type and diameter of the large diameter cone.

According to the large-diameter woodworking drill of the present invention, the guide screw 3 formed on the outer surface of the center drill is bitten into the hole drilled by the center drill 1, and the guide screw 3 formed on the outer surface of the center drill is bitten by the pitch of the guide screw 3 as the center drill rotates. A center drill can be sent.

Therefore, by setting the pitch of the guide screw 3 to a pitch suitable for the cutting capacity of the large diameter drill bit 2 installed in the center drill, the cutting amount (feed amount) of the large diameter drill hole 2 can be kept constant. A large diameter hole can be efficiently drilled without applying unnecessary force.

This is true whether the tool is used as a hand tool or an electric tool.

Furthermore, the large-diameter woodworking drill of the present invention has the advantage of being able to drill cleaner and more accurate holes, as can be seen from the fact that cutting waste of a certain thickness is discharged, for example.

[Brief explanation of the drawing]

The attached drawings show an embodiment of the large-diameter woodworking awl of the present invention. Figure 1 is a partially longitudinal front view applied to a counterbore awl, and Figure 2 is a partially longitudinal front view applied to a hole saw. be. 1... Center drill, 2... Large diameter drill, 3... Guide screw, 4... Guide screw.

Claims (1)

[Scope of utility model registration request] A large-diameter woodworking drill consisting of a center drill and a large-diameter drill, characterized in that a guide screw 3 with a pitch suitable for the depth of cut of the large-diameter drill 2 is provided on the outer surface of the center drill 1. .