JP2592885Y2 - Woodworking drill - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the improvement of woodwork drills.

[0002]

2. Description of the Related Art As a conventional woodworking drill, as shown in FIG. 3 and FIG. When performing drilling with such a woodworking drill with a leading screw, the leading screw 2 enters the wood, and then the material is cut by the cutting blade 3 at the tip of the drill body 1 and the marking blade 4 (drilling). It is a thing to open. This cutting blade 3
Cuts the bottom surface of the hole being drilled. The scribing blade 4 is for cutting off the wood fibers, thereby preventing the edge of the hole from being cut off and the wings from appearing.

[0003] Some conventional woodworking drills have a third or fourth drilling center cone 5 projecting from the center of the tip of a drill body 1 as illustrated in FIG. The center cone 5 is used for positioning a hole to be formed and for facilitating discharge of cutting chips through the spiral chip groove 6 of the body of the drill body 1.

[0004]

As shown in FIG. 4, a work piece 7 is formed by using the above-mentioned conventional woodworking tool with a thread.
In some cases, holes may be formed obliquely on the surface. In this case, first, the center position 0 of the hole to be machined on the surface of the workpiece 7 is drawn as the intersection of the black lines X and Y perpendicular to each other. Next, the tip of the leading screw is applied to the center position 0, and the drill body 1 is rotated by an electric drill body (not shown).
When the drill body 1 starts rotating, as shown in FIG. 4, the drill body 1 is slanted, so that the thread 8 projecting from the tip of the leading screw 2 rotates to form the workpiece 7. The tip screw 2 of the drill body 1 slides in the direction of the arrow B on the surface, causing a shift of the distance Δy as shown by the dashed line in the figure.

When the marking blade 4 at the tip of the drill body 1 that is rotating before the leading screw 2 sufficiently bites into the workpiece 7 hits the surface of the workpiece 7, the rotational force of the drill body 1 causes The drill body 1 is shifted in the black line X direction of FIG. 5 by the distance Δx.

From these facts, even when the tip of the leading screw 2 is set to a desired center position 0, when the drill body 1 starts rotating for drilling, the leading end of the leading screw 2 becomes as shown in FIG. Then, the position is shifted by Δx in the direction of the black line X and Δy in the direction of the black line Y, and is shifted to the position of the hole indicated by the dashed line in the figure.

[0007] In addition, as shown in FIG. 6, a case in which a hole is formed obliquely on the surface of a workpiece 7 using a woodworking drill having a central cone 5 at the tip of the drill body 1. In
Since the center cone 5 has no screw thread, there is no displacement of the woodworking drill due to the screw thread when the rotation of the drill body 1 is disclosed. However, since the center cone 5 has no thread, even when the center cone 5 is rotated, a thrust to bite into the workpiece 7 does not work. Therefore, when drilling with a hand-held electric tool using a wood drill with a central cone, there is a large resistance to pushing the central cone 5 into the workpiece 7 and no thrust works, so a great amount of labor is required. There was a problem that needed.

Further, regardless of whether a woodworking tool with a front thread or a woodworking tool with a center cone is used, when a hole having a large inclination angle from the vertical direction with respect to the surface of the workpiece 7 is formed, the front screw 2 is used. Of the work piece 7
Before hitting the surface of the workpiece, the marking blade 4 of the woodworking drill 1
And the tip of the leading screw 2 or the center cone 5 does not sufficiently enter the workpiece 7 and cannot be reliably positioned. Therefore, when the drill body 1 is rotated for drilling in this state, the marking blade 4 hits the workpiece 7 and moves the tip of the drill body 1, so that the drill is accurately positioned and drilled at the correct position. There was a problem that it was difficult.

In view of the above points, the present invention can accurately position the tip of the drill body even when drilling an inclined hole in the surface of the workpiece, and furthermore, the drill body is rotated and the drill body is first drilled. It is an object of the present invention to provide a new woodworking drill which can be lightly fed by an action of a thrust acting on a screw to reduce labor for work, and can be accurately drilled at a desired position.

[0010]

Means for Solving the Problems] woodworking tung of the present invention is Paulownia body (1) central tip portion center projection of the axis coaxial with the Paulownia body (1) to (9) projecting from the, the central projections the distal portion (9) formed in the key re portion (10), said central projection (9)
Threaded portion on the root end portion (11) formed of, scribe blade
(4) The length from the tip to the tip of the drill body (1) is longer than half the outer diameter of the marking blade (4) .

[0011]

With the above construction, when drilling a hole inclined with respect to the surface of the workpiece using a woodworking drill,
Since the drill portion of the central projection penetrates the workpiece sufficiently to position and maintain the drill body at a desired position, the thread portion of the central projection is covered when the drill body is rotated to cut a hole. It is possible to prevent the cutting part from sliding and changing its position when hitting the workpiece, and even if the marking blade of the drill body rotates and hits the workpiece, The drilling portion positions and supports the drill body so that the drill body does not shift.

After the thread at the central projection of the drill body is screwed into the workpiece, the screw action of the thread generates a thrust to advance the drill body, and the drilling operation can be performed with a light force. It has the effect of being advanced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a woodworking drill according to the present invention will be described below with reference to FIGS. In FIGS. 1 and 2, parts corresponding to those of the conventional example shown in FIGS. 3 to 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a side view of a main part on the tip side in a used state of the woodworking tool of this embodiment, and FIG. 2 is a side view showing the main part on the front end side of the woodworking tool body.
Is a cutting blade, 4 is a marking blade, 6 is a chip groove, 7 is a workpiece, 9
Is a central protrusion.

The central protruding portion 9 protrudes from the center of the tip of the drill body 1 in the form of a concentric cone, and extends from the distal end to the intermediate portion, such as a third, fourth or conical drill. And a thread portion 11 is formed from the intermediate portion to the root end portion.

That is, the sharp tip length 1 which is the length of the portion of the central projection 9 projecting from the tip of the marking blade 4 is formed so as to protrude more than half the outer diameter D of the marking blade 4. Note that the woodworking drill of this example is used when the inclination angle of the drill body from the vertical line to the surface of the workpiece 7 is within a range of up to 45 degrees. In order to cope with this, the tip length l of the drill is appropriately increased.

Next, a description will be given of the operation of drilling a hole inclined with respect to the surface of the workpiece by using the woodworking drill of the present embodiment configured as described above. First, the front end of the central projection 9 is pressed against the center position previously drawn on the surface of the workpiece 7 to perform positioning.

Next, the drill body 1 is rotated by an electric drill body (not shown). Then, the drill portion 10 bites into the workpiece 7 while rotating, and supports the positioning. Further, when the central projection 9 enters the workpiece 7, the thread 11 is moved to the workpiece 7.
Screwed into. At this time, even if the screw thread hits the surface of the workpiece 7 with the rotation of the drill body, since the drill portion 10 pierced into the workpiece 7 sufficiently positions and supports the drill body 1, The position of the projection 9 does not shift.

Further, even if the marking blade 4 hits the workpiece 7 due to the rotation of the cutting body 1, the cutting portion 10 pierced by this.
Since the drill body 1 sufficiently positions and supports the drill body 1, the drill body 1 does not deviate from the desired positioning position, so that the drill body can be accurately drilled at the desired position.

Further, when the single thread portion 11 is screwed into the workpiece 7, a thrust for advancing the drill body 1 is generated by the action of the screw, and thereafter, the drilling operation is performed by the drill body 1 with a lighter force. Can be.

[0021]

As described in detail above, according to the woodworking drill of the present invention, a central projection is provided at the center of the tip of the drill body and coaxial with the axis of the drill body. Is formed in a drill portion such as a third drill, a fourth drill, or a conical drill,
A thread is formed at the root end side of the central protrusion, and the length of the portion of the central protrusion that protrudes from the marking blade at the tip is longer than half the outer diameter of the marking blade. When drilling a hole inclined to the surface of the workpiece using
Since the drilled portion of the central projection penetrates the workpiece sufficiently to position and maintain the drill body at a desired position, the threaded portion of the central projection is covered when turning the drill body to advance the hole. It is possible to prevent the cutting part from sliding and changing its position when hitting the work material, and even if the marking blade of the drill body rotates and hits the work material while rotating, Since the drilled portion positions and supports the drill body so as not to cause a positional shift, there is an effect that a hole can be accurately drilled at a desired position.

Further, after the thread portion at the central projection of the drill body is screwed into the workpiece, the screw action of the thread portion generates a thrust for moving the drill body forward, and the drilling operation can be performed with a light force. There is an effect that the labor can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view of an essential part of a tip of a drill body in a drilling start state, showing an embodiment of a woodwork drill of the present invention.

FIG. 2 is a side view of a main part of the woodwork drill body taken out and shown.

FIG. 3 is a side view of a main part of a woodworking drill main body, which illustrates a conventional woodworking drill with a tip screw, in which a leading end side main part is taken out and shown.

FIG. 4 is a side view of a main part on the tip side of a drill body in a state in which drilling of the conventional woodworking drill with a thread is started.

FIG. 5 is an explanatory diagram for explaining the occurrence of a position error when a hole inclined with respect to the surface of a workpiece is drilled in a workpiece using the conventional threaded woodworking tool.

FIG. 6 is a side view showing a tip-side main part of a conventional woodworking drill with a central cone taken out.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Drill body 2 ... Tip screw 3 ... Cutting blade 4 ... Marking blade 5 ... Center cone 6 ... Chip groove 7 ... Workpiece 8 ... Thread 9 ... Central projection 10 ... Drill part 11 ... Thread part

Claims (1)

(57) [Scope of request for utility model registration] 1. A central projecting portion, which is concentric with the axis of the drill body, is formed at the center of the distal end of the drill body, and the distal end portion of the central projecting portion is formed in the drill portion, and the root of the central projecting portion is formed. A thread is formed on the end side to extend the length from the end of the marking blade to the end of the drill body.
Woodworking Kiri, characterized by being configured longer than half of the outer diameter of the scribing blade and is.