JPH0453613A - Chamfering cutter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a chamfer cutter used to form a recess having an inner diameter larger than the inner diameter of the opening edge of a hole formed by a drill. It is.

[Prior Art] Conventionally, as this type of chamfer cutter, there is one disclosed in, for example, Japanese Utility Model Application Publication No. 2-41809. In this technique, a chamfering cutter is constructed by engaging a main body having a cutting edge and a fixing plate in a groove of a drill, and connecting the two with bolts. By using this chamfer cutter, it is possible to form a recess on the edge of the opening at the same time as drilling the hole with a drill.

[Problems to be Solved by the Invention] However, when attaching the conventional chamfer cutter to a drill, first the main body and the fixing plate are engaged with the groove of the drill, and the holes provided in both are made to face each other. and,
Grip the main body and fixing plate with both holes facing each other,
Insert screws into both holes. Therefore, in these operations, it is necessary to accurately grasp the main body and fixing plate, position the holes, etc., and there is room for improvement in terms of workability in mounting.

In addition, since a part of the drill is sandwiched between the main body and the fixing plate, if the chamfer cutter is not securely attached to the drill, it may vibrate or a gap may be created between the drill and the chamfer cutter, from which chips can flow. etc. may be intruded.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to be able to fasten the drill to the drill with a simple operation without any gaps, to generate less vibration, and to prevent chips from being generated at the mounting part. To provide a chamfer cutter that can reliably prevent the intrusion of foreign substances.

[Means for Solving the Problems] In order to achieve the above object, the first invention provides a recess which is attached to a drill and has a recess having an inner diameter larger than the inner diameter of the hole at the opening edge of the hole drilled by the drill. A chamfering cutter for forming a chamfer cutter for forming a chamfer, comprising: an annular main body that can be fitted onto the drill; a fastening means for fastening the main body to the drill; and an axial line extending from the main body along the flank of the drill. The blade extends forward in the direction and has a cutting edge formed at the tip, and when attached to the drill, rotates along the flank with the inner surface of the blade in contact with the flank. The gist is a chamfering cutter in which the radius of curvature of the inner surface of the blade portion is made almost the same as the radius of curvature of the flank surface.

In addition to the configuration of the first invention, a second invention constitutes a fastening means by a screw hole penetrated through the main body portion and a push screw screwed into the screw hole, and the screw hole is connected to the screw hole. Its gist is a chamfer cutter formed on the side facing the cutting edge of the main body.

In addition to the configuration of the first or second invention, the gist of the third invention is a chamfer cutter in which the front edge of the outer circumferential surface of the blade part with respect to the cutting rotation direction of the drill is chamfered to have a curved shape.

A fourth invention is a chamfering cutter that is attached to a drill and is used to form a recess with an inner diameter larger than the inner diameter of the hole at the opening edge of a hole drilled by the drill, which can be externally fitted onto the drill. The main body has an annular shape, and the blade extends forward in the axial direction from the main body along the flank of the drill, and has a cutting edge formed at the tip, and the radius of the inner circumferential surface of the main body is is approximately the same as the radius of curvature of the flank surface of the drill, and the inner peripheral surface allows the land that protrudes from the flank surface to enter when installed on the drill, and also guides the land toward the blade side. Its gist is a chamfering cutter with a guide groove formed therein.

[Operation] When attaching a chamfer cutter to a drill in the first invention, the annular main body is fitted onto the drill, and with the inner surface of the blade in contact with the flank, the chamfer is cut along the flank. Move the chamfering cutter forward while rotating it. After the chamfer cutter is moved to a predetermined position on the drill, the chamfer cutter is fastened to the drill by the fastening means.

When the chamfering cutter is attached to the drill as described above, the inner surface of the blade comes into contact with the flank and there is no gap between the two. This prevents chips from entering the gap when forming the recess.

In the second invention, when fastening the chamfer cutter to the drill, the push screw screwed into the screw hole is tightened. Then, the tip of the push screw comes into contact with the flank of the drill. When the push screw is further tightened, a force is applied to the flank face of the drill against the opposing cutting edge, and the inner surface of the blade portion having the cutting edge comes into pressure contact with the flank face.

In the third invention, since the front edge of the outer circumferential surface of the blade portion in the cutting rotation direction of the drill is curved, this curved portion does not interfere with chips when forming a recess.

Therefore, chips can escape from the curved surface portion.

In the fourth invention, when attaching the chamfer cutter to the drill, the land is engaged in the guide groove, and in this state, the chamfer cutter is advanced while rotating along the land. Then, the chamfering cutter is guided so that the inner surface of the blade is in contact with the flank of the drill.

When the chamfering cutter is installed, the inner peripheral surface of the main body comes into contact with the flank of the drill, and there is no gap between the two. Therefore, the chamfering cutter is stable against the drill by the amount of space that is eliminated. Furthermore, when forming the recess, chips are prevented from entering the gap.

[First Embodiment] A first embodiment embodying the present invention will be described below with reference to FIGS. 1 to 5.

Figure 2 is a front view of the drill l and chamfering cutter 2;
The figure is a bottom view of the drill 1. This drill 1 consists of a shank 3 and a shaft body 4, and the shaft body 4 is formed with two helical grooves 5 that form a spiral with respect to the axis. Two helical flanks 6 are formed on the outer circumferential surface of the shaft body 4 by both helical grooves 5 . Here, assuming that the cutting rotation direction of the drill 1 is X, a narrow land 7 is located at the front edge of each flank 6 in the same cutting rotation direction X, and the land 7 is slightly protruded radially outward from the flank 6 It is set in. In the main body embodiment, the radius of curvature A of the flank 6 is 4.85 mm,
The radius of curvature B of the land 7 is 5.0 mm.

FIG. 1 is a front view of the chamfering cutter 2 attached to the drill l, and FIG. 5 is a bottom view of the chamfering cutter 2. This chamfering cutter 2 is equipped with an annular main body portion 8 that can be fitted onto a drill l. The radius C of the inner circumferential surface 8a of the main body portion 8 is set to 5.0+0°01 mm, which is approximately the same as the radius of curvature B of the land 7 of the drill l. A pair of screw holes 9 are provided through the main body portion 8 at opposing positions, and a push screw 10 is screwed into each screw hole 9. In this embodiment, these screw holes 9 and push screws 1O constitute a fastening means for fastening the main body 8 to the drill 1.

A pair of blade portions 11 spirally extend from a position below each screw hole 9 in the main body portion 8 in correspondence with the flank surface 6 of the drill 1. Each blade portion 11 extends to a position below the screw hole 9 opposite to its upper end, and has a conical oblique curved surface 12 formed at its lower end (third
, see Figure 5).

The angle α that this oblique curved surface 12 makes with the axis is 45° in this embodiment, but it can be changed to 30°, 60°, etc. as appropriate. The front edge of the obliquely curved surface 12 with respect to the cutting rotation direction X of the drill 1 is a cutting edge 13 . Further, the front edge 11a of the outer peripheral surface of each blade portion 11 is chamfered to have a curved shape.

The radius of curvature of the inner surface 11b of each blade portion 11 is approximately the same as the radius of curvature A of the flank surface 6 at any location.
．． It is 85±0.01mm.

When attaching the chamfering cutter 2 configured as described above to the drill l, the double set screws 10 are set back from the inner circumferential surface 8a of the main body portion 8. In this state, the main body 8 is placed over the tip of the drill l. At this time, the radius C of the inner circumferential surface 8a of the main body 8 is almost the same as the radius of curvature B of the land 7 in the drill l, so the main body 8 is placed at the tip of the drill 1 with the inner circumferential surface 8a in contact with the land 7. It is covered over the body.

Since the radius of curvature of each inner surface 11b of the double-edged portion 11 of the chamfering cutter 2 is slightly smaller than the radius of curvature B of the land 7, both lands 7 cannot be brought into contact with the same inner surface 11b. Therefore, as shown in FIG. 3, the inner surface 11b of the blade portion 11 is slightly shifted from both lands 7.
Adjust the angle of the chamfer cutter 2 with respect to the drill l.

In this state, since the radius of curvature of the inner surface 11b of the double-edged portion 11 is approximately the same as the radius of curvature A of the flank surface 6 of the drill 1, the inner surface 11b abuts against the flank surface 6.

With only the inner surface 11b of the blade part 11 in contact with the flank surface 6 as described above, align the chamfering cutter 2 with the spiral shape of the flank surface 6, and while rotating it as shown by the arrow E in FIG. advance. Then, when the chamfering cutter 2 is advanced to a predetermined position as shown in FIG. 1, each set screw 10 is tightened.

In this embodiment, the screw hole 9 into which the push screw IO is screwed is formed on the side of the main body 8 that faces the cutting blade 13. Therefore, when the push screw 10 is tightened as described above, the tip of the push screw 10 will always come into contact with the flank 6 of the drill 1, no matter where the chamfering cutter 2 is located on the drill 1.

When the set screw 10 is further tightened, the cutting blade 13 on the opposite side
A force is applied to the flank 6 side of the drill l to the blade portion 11 having the shape. For example, when the set screw 10 on the right side is tightened in FIG. do. Therefore, by tightening both set screws 10, the chamfer cutter 2 can be effectively fastened.

When the chamfering cutter 2 is fastened to the drill l in this manner, the inner surface 11b of the double-edged portion 11 comes into contact with the flank surface 6, so that there is no gap between them.

By the way, when drilling and chamfering work is performed using the drill 1 to which the chamfering cutter 2 is attached, the drill 1 is attached to a chuck (not shown) of a drilling machine or the like, and the drill 1 is rotated in the cutting rotation direction X. While rotating the machine, its tip is brought into contact with a workpiece or other workpiece.

Then, as shown in FIG. 1, a hole H is drilled in the work W by the drill L. At this time, cutting waste is discharged from the helical groove 5 of the drill l. When the drill l is further advanced, the cutting edge 13 of each blade part 11 of the chamfering cutter 2
It comes into contact with the opening edge of the hole H made by. Then, the cutting edge 13 forms an inverted truncated conical recess Ha having an inner diameter larger than the inner diameter of the hole H at the opening edge of the hole H.

Since there is no gap between each blade portion 11 and the flank surface 6 of the drill l, chips generated due to the formation of the recess Ha do not enter there. In particular, in this embodiment, the inner surface 11b of each blade portion 11 is connected to the flank surface 6 by the push screw lO as described above.
Since the material is pressed against the material, the intrusion of chips can be effectively prevented. Furthermore, in this embodiment, since the front edge 11a of the outer peripheral surface of each blade portion 11 is chamfered and has a curved shape,
This curved surface portion does not interfere with chips, and the chips can escape from the curved surface portion.

Furthermore, when forming the recess Ha, the blade portion 11
Since chips and the like do not enter between the inner surface 11b and the flank surface 6, unnecessary vibration of the chamfering cutter 2 due to this entry is suppressed.

In this way, according to this embodiment, the chamfering cutter 2 can be firmly attached to the drill 1 with a simple operation.
Installation workability is improved compared to conventional ones. Furthermore, when forming the recess Ha, it is possible to prevent chips from entering between the blade portion 11 and the flank face 6, thereby suppressing vibration generation.

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7.

FIG. 6 is a longitudinal cross-sectional view of the chamfering cutter 2, and FIG. 7 is a cross-sectional view taken along the line ■--■ in FIG. In this embodiment, the radius C of the inner circumferential surface 8b of the main body portion 8 and the radius of curvature of the inner surface 11b of each blade portion 11 are both made substantially the same as the radius of curvature A of the flank surface 6 of the drill l. Further, the inner circumferential surface 8b of the main body portion 8 allows the land 7 protruding from the flank 6 to engage when the chamfering cutter 2 is attached to the drill l, and the land 7
Two guide grooves 14 are formed to guide the blade toward the blade portion 11 side. These guide grooves 14 are formed on the inner circumferential surface 8 of the main body 8.
b Extends downward from the upper end to reach the upper end of each blade portion 11. The configuration other than the above is the same as the first embodiment.

Therefore, according to this embodiment, in addition to producing the same functions and effects as those of the first embodiment, when attaching the chamfering cutter 2 to the drill l, the land 7 is inserted into each guide groove 14,
In this state, the chamfering cutter 2 is rotated and advanced along the spiral shape of the land 7. Then, the chamfering cutter 2 is guided so that the inner surface of the blade portion 11 is in contact with the flank surface 6 of the drill 1.

When the chamfering cutter 2 is attached, the inner circumferential surface 8b of the main body portion 8 comes into contact with the flank surface 6 of the drill l, and there is no gap between the two. Therefore, the chamfering cutter 2 is stabilized relative to the drill l by the amount that the gap is eliminated. Furthermore, when forming the recess Ha, chips are prevented from entering the gap portion.

It should be noted that the present invention is not limited to the configuration of the above-mentioned embodiments. For example, the number of blade portions 11, screw holes 9, and push screws 10 may be increased to one or three or more, within a range that does not depart from the spirit of the invention. You can change it as you like.

In addition, the blade part 11 is slightly bent inward at the boundary with the main body part 8 so that the radius of curvature of the inner surface 11b at the lower end becomes smaller. flank 6
The radius of curvature A may be approximately the same as the radius of curvature A of .

[Effects of the Invention] According to the first invention, it is possible to eliminate the gap between the flank face of the drill and the inner surface of the blade part of the chamfering cutter, thereby preventing chips from entering the same part, and also to prevent chips from entering the gap. It is possible to suppress vibrations based on

According to the second invention, in addition to the effects of the first invention, the blade part can be effectively pressed against the flank surface of the drill by tightening the push screw, and the intrusion of chips and vibration can be suppressed. It can be done reliably.

According to the third invention, in addition to the effects of the first or second invention, chips can be released from the curved surface portion formed on the outer peripheral edge of the blade portion.

According to the fourth invention, it is possible to eliminate the gap between the inner circumferential surface of the main body of the chamfer cutter and the flank surface of the drill to prevent chips from entering the same part, and the attachment of the chamfer cutter to the drill is Stability can be improved, and furthermore, the positioning of the blade portion relative to the flank surface becomes easier.

[Brief explanation of drawings]

Figures 1 to 5 show a first embodiment embodying the present invention, Figure 1 is a front view of a drill with a chamfer cutter attached, Figure 2 is a front view of the drill and chamfer cutter, and Figure 3 is a front view of the drill and chamfer cutter. is a bottom view of a drill with a chamfer cutter attached to it, FIG. 4 is a bottom view of the drill, FIG. 5 is a bottom view of the chamfer cutter, and FIG. 6.7 shows a second embodiment of the present invention. Figure 6 is a vertical cross-sectional view of the chamfering cutter, and Figure 7 is the ■ of Figure 6.
It is a sectional view taken along the line -■. 1... Drill, 6... Flank surface, 7... Land, 8
...Body portion, 8b...Inner circumferential surface, 9...Screw hole forming part of the fastening means, 10...Push screw forming part of the fastening means, 11...Blade portion , 11a... Front edge, 11b... Inner surface, 13... Cutting edge, 14... Guide groove, A... Radius of curvature of flank surface, C... Radius of inner peripheral surface of main body, D ... radius of curvature of the inner surface of the blade, H ... hole,
Ha: recess, L: axis, X: cutting rotation direction. Patent applicant: Omi Kogyo Co., Ltd. agent, patent attorney: Hironobu Onda (and 1 other person)! Figure 6

Claims (1)

[Claims] 1. A recess (Ha) is attached to the drill (1) and has a recess (Ha ) for forming a chamfer cutter, comprising: an annular main body (8) that can be fitted onto the drill (1); and fastening means (9) for fastening the main body (8) to the drill (1). , 10), and a flank (6) of the drill (1) from the main body (8).
It extends forward along the axis (L) direction, and has a cutting edge (
13) is formed, and when attached to the drill (1), the blade part (11)
The blade portion (11
) is characterized in that the radius of curvature (D) of the inner surface (11b) is approximately the same as the radius of curvature (A) of the flank (6). 2. A fastening means is constituted by a screw hole (9) provided through the main body (8) and a push screw (10) screwed into the screw hole (9), and the screw hole (9) The chamfering cutter according to claim 1, characterized in that the chamfering cutter is formed on a side of the main body (8) facing opposite to the cutting blade (13). 3. The blade portion (1) relative to the cutting rotation direction (X) of the drill (1)
1) The chamfer cutter according to claim 1 or 2, characterized in that the front edge (11a) of the outer peripheral surface is chamfered to have a curved shape. 4. Attached to the drill (1), for forming a recess (Ha) with an inner diameter larger than the inner diameter of the hole (H) at the opening edge of the hole (H) drilled by the drill (1). The chamfering cutter includes: an annular main body (8) that can be fitted onto the drill (1); and a flank (6) of the drill (1) from the main body (8).
It extends forward along the axis (L) direction, and has a cutting edge (
13), and a radius (C) of the inner circumferential surface (8b) of the main body (8).
) is approximately the same as the radius of curvature (A) of the flank (6) of the drill (1), and the inner peripheral surface (8b) has a land that protrudes from the flank (6) when attached to the drill (1). A chamfering cutter characterized in that a guide groove (14) is formed to allow the land (7) to engage and guide the land (7) toward the blade portion (11).