JPH05318217A - 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 consisting of several pieces simply and quickly without requiring skillfulness and which has no risk of influencing the quality of the work machined. CONSTITUTION:A cutter body 1 is provided with a cutting edge at the tip of a bottom-equipped cylinder, and also a plurality of grooves 1c are formed in the cylindrical part 1a leading to the tip from a specified part, wherein a disc- shaped exhaust tool 2 provided with a plurality of long holes 2a alongside the cylindrical part of the cutter body 1 except the grooves 1c is fitted slidably in this part with long holes 2a.

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 chips remain in the cutter to a certain extent or more, it becomes impossible to continue cutting. Therefore, conventionally, the following measures have been taken in order to easily discharge the chips left inside the cutter. Has been done.

5 to 7 are perspective views showing the construction of a conventional hole cutter used for processing a relatively soft material such as synthetic resin. In the structure shown in FIG. 5, a seated spring 53 provided with an appropriate seat at the tip of a compression coil spring is arranged along a drill 52 fixed to the center of a cutter body 51 as a center member, and cut by the spring pressure. It is configured to automatically discharge dross.

Further, in the structure shown in FIG. 6, a plurality of cutout grooves 62 extending to the tip of the cylindrical portion of the cutter body 61 are provided.
Are divided into equal parts, and a notch groove 62 is used to insert a screwdriver or an appropriate rod from the outside of the cutter body 61 to discharge the internal chips.

Further, in the structure shown in FIG. 7, a plurality of through holes 72 are diagonally formed in the bottom of the cutter body 71, and a rod is inserted into the cutter body 71 through the through holes 72,
A hammer etc. is used to strike out the chips through the stick.

[0007]

By the way, in the above-mentioned conventional measures for discharging cutting chips, as shown in FIG. 5, the cutting portion of the work material is above a certain level, such as immediately before the completion of cutting of the work material. When the wall is thinned, the spring pressure of the seated spring 53 forcibly extrudes the cut dust in a state where it is not yet completely cut, and the cut surface of the processed hole is chipped to cause unevenness. Not only the finished surface becomes extremely bad, but also during the processing of the synthetic resin product, there is a possibility that cracks may occur and the product may become defective.

Further, in the structure shown in FIG. 6, it is necessary to sequentially insert a screwdriver or the like through each notch groove 62 to gradually discharge the chips, so that not only some skill is required, but also a cutter. If the chips are twisted in the body 61, there is a problem that the discharge becomes extremely difficult.

Further, in the structure shown in FIG. 7, the through hole 72
In order to insert the rod into the cutter body 71, it is necessary to remove the cutter body 71 from an electric drill or the like, which has a disadvantage that workability is poor and time loss is large.

The present invention has been made in view of the above circumstances, and it is possible to easily and quickly discharge chips left in a hole cutter without requiring skill, and to discharge several chips at once. The purpose of the present invention is to provide a hole cutter that does not affect the quality of the work material.

[0011]

A structure for achieving the above object will be described with reference to FIGS. 1 to 3 which are drawings of an embodiment. A hole cutter according to the present invention has a tip end of a bottomed cylindrical body. In the cutter body 1 in which a cutting edge C is formed, and in the cylindrical portion 1a, a plurality of cutout grooves 1c from a predetermined portion to a tip portion are formed, the cutout groove 1c of the cutter body 1 is removed. A plurality of arc-shaped elongated holes 2a along the cylindrical portion
The disc-shaped member (discharging tool) 2 in which is formed is characterized in that it is slidably fitted into the cylindrical portion 1a at the portion of each elongated hole 2a.

[0012]

[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. Dust is discharged. In this discharging operation, the scraps move while being pressed by the disk-shaped member 2 in surface contact, so that no kinking occurs and the disk-shaped member 2 is moved from the side surface of the cutter body 1. Therefore, it is not necessary to remove the cutter body 1 from the electric drill or the like. Further, since the disc-shaped member 2 does not apply pressure to the work material during cutting, it does not affect the quality of the work material.

[0013]

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 3 at the center of the bottom portion 1b, and in this state, the base portion of the drill 3 is an electric drill or the like. Be attached to.

The bottom portion 1 is provided on the cylindrical portion 1a of the cutter body 1.
Three notch grooves 1c extending from the vicinity of b to the tip end portion are formed at positions that divide the cylindrical portion 1a into three equal parts. A disc-shaped discharge tool 2 is fitted in the cylindrical portion 1a of the cutter body 1 so as to be slidable in the axial direction.

The ejector 2 is, as shown in the front view of FIG.
A through hole 2b for inserting the drill 3 is formed in the central portion, and three pieces each of which is capable of inserting each piece of the cylindrical portion 1a divided into three by the cutout groove 1c around the through hole 2b are formed. With a structure in which an arc-shaped elongated hole 2a is formed, and in a state in which this discharge tool 2 is fitted into the cutter body 1, each piece of the cylindrical portion 1a is inserted into each elongated hole 2a and the through hole 2b is inserted. With the drills 3 inserted, they are slidably supported in the axial direction of the cutter body 1 by using the drills as guides.

Here, the radial dimension of the portion of the discharge tool 2 outside the elongated hole 2a, that is, the projection margin that projects outward from the outer peripheral surface of the cutter body 1 when attached to the cutter body 1 is at the fingertip. The thickness may be about 6 mm, for example, and the thickness may be 5 mm or less for weight reduction. Although any metal can be used as the material of the discharge tool 2, it is desirable to use a light metal-based material for weight reduction.

Then, the drill 3 in the through hole 2b of the discharge tool 2
The clearance with respect to the outer diameter surface of the discharge tool 2 is preferably about 0.05 to 0.1 mm so that the discharge tool 2 can smoothly slide in the cutter body 1 without being twisted. Chamfer or R on each edge
It is desirable to form the surface so that it is not caught. Further, in order to prevent the discharge tool 2 from being twisted when sliding, it is desirable to form a thick portion 2c around the through hole 2b to increase the guide distance from the drill 3.

Further, in this embodiment, in order to prevent the discharge tool 2 from falling in vertical downward work or the like, a small hole is formed from the outer periphery of the thick portion 2c toward the through hole 2b as shown in FIG. , The ball 2d and the compression coil spring 2 inside thereof
A structure is adopted in which the ball 2d is elastically pressed into the through hole 2b by inserting e and the ball 2d is fitted into the twist groove of the drill 3.

When using the above embodiment of the present invention, the discharging tool 2 is inserted from the tip side of the cutter body 1 toward the bottom portion 1b side. At this time, the ball 2d fits properly into the twist groove of the drill 3, but by moving the discharge tool 2 from the outside with a finger, the compression coil spring 2e is compressed and the ball 2d retracts, and the twist groove is moved. Can be exceeded. Then, for example, the cutting is performed in a state where the ball 2d is fitted into and locked in the twist groove of the drill 3 at an approximately central portion in the axial direction of the cutter body 1. In this state, the discharge tool 2 needs to rotate along the twist groove in order to move to the tip side of the cutter body 1 due to its own weight, but the cylindrical portion 1a of the cutter body 1 is inserted into the elongated hole 2a.
This rotation is prevented by the structure in which the respective pieces are inserted, and the ejecting tool 2 does not drop by a force of about its own weight even during vertical work.

Every time the processing of one hole is completed, cutting wastes are accumulated in the cutter body 1 one by one, but if the cutting wastes are accumulated to a certain extent or more, the discharging tool 2 is considerably affected by the pressing force at the time of processing. The force is applied, and it retreats in sequence with each processing. Then, when the discharge tool 2 is pushed to the vicinity of the retracted end and the cutter body 1 is almost completely filled with cutting dust, the discharge tool 2 is placed on the tip side of the cutter body 1 by placing a finger on the protruding portion of the cutter tool 1 to the outside. To move. As a result, the chips in the cutter body 1 are pushed in a plane by the discharge tool 2 and are easily discharged to the outside without being twisted.

The experimental results of actually discharging chips by using the above-described embodiments of the present invention will be described together with comparative examples. [Table 1] is a summary of the experimental results. The case where the conventional hole cutter shown in FIGS. 5, 6 and 7 is used as a comparative example.
We investigated the time and workability required to discharge all of the scraps, and the condition of the cut surface of the work material. As is clear from this [Table 1], in the examples of the present invention, the time required for discharging and the workability thereof were superior to all the comparative examples, and no influence was observed on the cut surface.

[0022]

[Table 1] As a mechanism for preventing the discharge tool 2 from falling during vertical work or the like, a mechanism as shown in a perspective view of the cutter body 1 in FIG. 4 can be adopted instead of the mechanism of the above-described embodiment. That is, in this example, each cutout groove 1c formed in the cylindrical portion 1a of the cutter body 1 is bent at the end portion on the side of the bottom portion 1b into a substantially L shape, and the discharge tool 2 is attached to the cutter body 1. When processing is performed, the discharging tool 2 is rotated with the bending tool A inserted into the bent portion A to prevent the discharging tool 2 from falling.

[0023]

As described above, according to the present invention,
A disc in which a plurality of notched grooves extending to the tip are formed in the cylindrical portion of the cup-shaped cutter body, and a plurality of long holes that are fitted into each piece of the cylindrical portion divided by the notched grooves are formed. Since it has a structure in which the shaped discharge tool is attached to the cutter body so as to be slidable in the axial direction, by moving the discharge tool to the tip side after processing, It is pushed in a plane and discharged to the outside without being twisted. Moreover, since the discharging tool is moved by pushing with a finger from the side surface of the cutter body, it is not necessary to remove the cutter body from the electric drill or the like in this discharging operation. Further, since the discharge tool does not apply pressure to the work material during cutting, it does not affect the quality of the work material.

[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 an external perspective view of a cutter body 1 according to another embodiment of the present invention.

FIG. 5 is a perspective view of the appearance of a conventional hole cutter with measures against cutting chips.

FIG. 6 is an external perspective view of another conventional hole cutter.

FIG. 7 is a partially cutaway perspective view of still another conventional hole cutter.

[Explanation of symbols]

 1 Cutter main body 1a Cylindrical part 1b Bottom part 1c Notch groove C Cutting edge 2 Discharge tool 2a Long hole 2b Through hole 2c Thick part 2d Ball 2e Compression coil spring 3 Drill

Claims (1)

[Claims] 1. A cutter body in which a cutting edge is formed at the tip of a bottomed cylindrical body, and a plurality of notched grooves extending from a predetermined portion to the tip is formed in the cylindrical portion of the cutter body. A hole cutter in which a disk-shaped member having a plurality of arc-shaped elongated holes formed along a cylindrical portion excluding the cutout groove is slidably fitted into the cylindrical portion at each elongated hole portion.