JPH05318216A - Hole cutter - Google Patents

Abstract

PURPOSE:To provide a hole cutter which can exhaust splinters stagnating in the body of the cutter in a lump simply and quickly without requiring skillfulness. CONSTITUTION:A plurality of openings 1c stretching in the axial direction are provided in a cylindrical part 1a of a cup-shaped cutter body 1 where a cutting edge C is formed at the tip, and a disc-shaped member (exhaust tool) 2 slidable in the axial direction along the internal circumference of the cylindrical part 1a is inserted in this body 1 of cutter, and to the periphery of this disc-shaped member 2, a plurality of projections (knobs) 3 are secured which protrude outward through the abovementioned openings 1c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called hole cutter for cutting a plate-shaped work material into a circular shape to form a hole.

[0002]

2. Description of the Related Art Generally, in a hole cutter, a cutter having a bottomed cylindrical shape (hereinafter referred to as a cup shape) having a cutting edge formed at its tip is pressed against a work material while being rotated, To cut a circle to make a hole,
The disc-shaped cut piece (cut dust) generated by this cutting remains inside the cutter.

If such cutting dust accumulates inside the cutter to some extent, it becomes impossible to continue cutting. Therefore,
Conventionally, as illustrated by a partially cutout external view in FIG. 4, in a hole cutter for machining a metal-based relatively hard material, an opening 42 extending in the axial direction is formed in a cylindrical portion of a cutter body 41. Or, a plurality of through holes 43 are provided diagonally in the bottom of the cutter body 41, and a screwdriver or a suitable rod is inserted from the outside of the opening 42 and used as a lever to pry out the cutting dust. , A method of discharging internal chips by hitting the driver or the like diagonally, or inserting a rod into the cutter body 41 from the through hole 43 and tapping out the chips with a hammer or the like through the rod. Etc. are adopted.

[0004]

In the conventional method of discharging cutting chips as described above, in the method of discharging the cutting chips from the side by inserting a driver or the like through the opening 42, the cutting chips in the cutter body 41 are twisted. There is a problem that the discharge work becomes extremely difficult and requires a certain amount of skill, and also in the method of tapping out from the through hole 43 at the bottom of the cutter body 41 through a rod, the work is also difficult due to the clogging of chips. Not only that, but also the cutter body 41 needs to be removed from an electric drill or the like, which has the disadvantage of poor workability and a large loss of time.

An object of the present invention is to provide a hole cutter capable of easily and quickly discharging the chips left in the hole cutter without requiring skill, and easily discharging several chips at once. Especially.

[0006]

A structure for achieving the above-mentioned object will be described with reference to FIG. 1 which is an embodiment drawing, and a hole cutter of the present invention is cut at a tip portion of a bottomed cylindrical body. Inside the cutter body 1 in which the blade C is formed, and a plurality of openings 1c extending in the axial direction penetrating the inside and outside of the cylindrical portion 1a are formed in the cylindrical portion 1a, the cylindrical portion 1a is formed. A disc-shaped member (discharging tool) 2 which is slidable in the axial direction is inserted along the inner peripheral surface of the disc-shaped member, and the openings 1c of the cutter body 1 are provided on the outer periphery of the disc-shaped member 2.
It is characterized in that a plurality of protrusions (knobs) 3 each protruding to the outside via the are fixed.

[0007]

[Function] When the disc-shaped member 2 is moved to the tip side of the cutter body 1 after the cutting process is performed with the disc-shaped member 2 attached to the cutter body 1, the cutting stuck in the cutter body 1 is cut. The dust is pushed by the disc-shaped member 2 and discharged to the outside. In this discharging operation, since the scraps move while being pressed uniformly by the disk-shaped member 2 by surface contact, no kinking occurs, and the cylindrical portion 1a of the cutter body 1 moves to the side thereof. Since such discharge is performed by operating the protruding protrusion, the cutter body 1
It is possible to discharge chips without removing them from an electric drill or the like.

[0008]

1 is an external perspective view of an embodiment of the present invention, and FIG. 2 is a central sectional view thereof. The cup-shaped cutter body 1 including the cylindrical portion 1a having the cutting edge C formed at the tip and the bottom portion 1b is fixed to the drill 4 at the center of the bottom portion 1b, and in this state, the base portion of the drill 4 is an electric drill or the like. Be attached to.

The cylindrical portion 1a of the cutter body 1 has three openings 1c which penetrate the cylindrical portion 1a inward and outward and extend axially from near the bottom portion 1b to near the tip portion.
Is formed at a position that divides the cylindrical portion 1a into three. A disc-shaped discharge tool 2 is axially slidably inserted into the cylindrical portion 1a.

The discharge tool 2 has a front view as shown in FIG.
A through hole 2a for penetrating the drill 4 is formed in the center thereof, and the outer diameter dimension thereof is slightly smaller than the inner diameter dimension of the cylindrical portion 1a of the cutter body 1, and
Three female screws 2b are formed on the outer peripheral surface of the cutter body 1 at equal intervals.
In a state where the knob 3 is inserted in a, a knob 3 described later is screwed in through each opening 1c of the cylindrical portion 1a. The clearance of the through hole 2a with respect to the outer diameter surface of the drill 4 is preferably, for example, about 0.05 to 0.1 mm so that the discharge tool 2 can smoothly slide in the cutter body 1 in the axial direction without twisting. For that purpose, it is desirable that all the edge portions of the discharging device 2 be R-faces. Further, the discharge tool 2 is formed with a thick portion 2c projecting toward the tip side of the cutter body 1 around the through hole 2a.
With this, the guide length between the drill 4 and the drill 4 is increased to prevent twisting of the discharging tool 2 when sliding, and as will be described later, it is possible to discharge the innermost cutting chips in the cutting chip discharging operation. There is. That is, this thick portion 2
The protrusion margin of c is such that the chips left in the innermost part of the cutter body 1 are discharged from the tip of the cutter body 1 to the outside in a state where the discharge tool 2 reaches the forward end in the cutter body 1. It has different dimensions.

The knob 3 described above, as shown in FIG.
A male screw 3a screwed into the female screw 2b of the discharging tool 2, a neck 3b penetrating the opening 1c of the cylindrical portion 1a, and a head 3c protruding outward from the cylindrical portion 1a through the opening 1c.
The protrusion margin from the outer peripheral surface of the cylindrical portion 1a to the outside is such that a finger is caught, for example, about 6 mm.

When using the above-described embodiment of the present invention, first, the ejector 2 with the knob 3 removed is inserted from the tip side of the cutter body 1 and the opening is formed in each female screw 2b on the outer peripheral surface thereof. The knob 3 is screwed in via 1c to bring it to the state of FIG. 1 or 2, and the cutting process is performed. Every time one machining is performed, chips are accumulated in the cutter body 1, and the discharging tool 2 is pushed backward as it goes along.
When the discharge tool 2 reaches the vicinity of the retreat limit, that is, the knob 3 reaches the vicinity of the rear end of the opening 1c of the cutter body 1 by several processes, place a finger on the knob 3 from the side of the cutter body 1. Hang it to move the discharge tool 2 to the tip side. As a result, the chips in the cutter body 1 are uniformly pushed in a planar manner by the discharge tool 2, and are easily discharged to the outside of the cutter body 1 without being twisted. At this time, due to the presence of the thick-walled portion 2c provided in the discharging tool 2, the forward end of the discharging tool 2, that is, the knob 3 reaches the tip of the opening 1c, and is clogged in the innermost part of the cutter body 1. It is possible to discharge the cutting chips that are present.

Experimental results of actually discharging chips using the above-described embodiment of the present invention will be described together with a comparative example. [Table 1] summarizes the experimental results, and as a comparative example,
Using the conventional hole cutter shown in FIG. 4, a method of inserting a driver through the opening 42 of the cutter body 41 to discharge the chips and a method of inserting a rod from the through hole 43 at the bottom of the cutter body 41 and hammering The method of hammering out the cutting chips was given, and the time required for discharging all of the cutting chips and the workability thereof were investigated in a state where each of the cutter bodies was clogged with five cutting chips. As is clear from Table 1 above, it was confirmed that the examples of the present invention are superior to the comparative examples in both the required discharge time and the workability.

[0014]

[Table 1]

[0015]

As described above, according to the present invention,
A plurality of openings extending along the axial direction are formed in the cylindrical portion of the cup-shaped cutter body, and a circle that is slidable in the axial direction along the inner peripheral surface of the cylindrical portion inside the cutter body. Since a plate-shaped ejector is inserted and a plurality of knobs that stick out to the outside through the openings of the cutter body are fixed to the outer periphery of the ejector, it is necessary to use the knobs after drilling. By moving the discharging tool to the tip side, the chips left in the cutter body due to processing are uniformly pressed in a planar shape and easily discharged to the outside without being twisted. Moreover, since the movement of the discharging tool is performed by the operation from the side surface of the cutter body, it is not necessary to remove the cutter body from the electric drill or the like for discharging, and skill is required even when several chips are accumulated. These can be discharged all at once without any.

[Brief description of drawings]

FIG. 1 is an external perspective view of an embodiment of the present invention.

FIG. 2 is a central sectional view of the embodiment of the present invention.

FIG. 3 is a front view of the discharging tool 2.

FIG. 4 is a partially cutaway perspective view showing a structural example of a conventional hole cutter.

[Explanation of symbols]

 1 Cutter body 1a Cylindrical part 1b Bottom part 1c Opening part 2 Discharge tool 2a Through hole 2b Female screw 2c Thick part 3 Knob 3a Male screw 3b Neck part 3c Head part 4 Drill

Claims (1)

[Claims] 1. A cutter in which a cutting edge is formed at a tip portion of a bottomed cylindrical body, and a plurality of openings are formed in the cylindrical portion so as to extend inward and outward through the cylindrical portion and extend along an axial direction. A disc-shaped member that is slidable in the axial direction along the inner peripheral surface of the cylindrical portion is inserted inside the main body, and the openings of the cutter body are provided on the outer periphery of the disc-shaped member. A hole cutter in which a plurality of protrusions that protrude to the outside are fixed to each other via.