JP2000107918A - Throw away tip and cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a throw away tip and a cutting tool which are capable of efficiently installing and replacing the throw away tip. SOLUTION: A center drill 3 is combined with an outer peripheral cutting edge tip 5 to form a throw away tip 7. That is, the shaft part 17 of the center drill 3 is fit-inserted into a tip side through hole 25 of the outer peripheral cutting edge tip 5 in the direction of arrow A, and thus the center drill 3 is combined with the outer peripheral cutting edge tip 5. At this time, the drill side tapered part 19 of the outer peripheral cutting edge tip 5 is seated on the tip side tapered part 29 of the outer peripheral cutting edge tip 5, and thus the center drill 3 is structured to be integrated with the outer peripheral cutting edge tip 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applicable to, for example, a drill or an end mill as a rotary tool, and is provided with a throwaway tip comprising a center drill and an outer peripheral tip, and the throwaway tip. It relates to a cutting tool.

[0002]

2. Description of the Related Art Conventionally, as a drill having a replaceable cutting edge, for example, a drill in which a center drill and an outer peripheral cutting tip are attached to the tip side of a holder is known (Japanese Utility Model Laid-Open No. 64-34).
No. 111, Japanese Utility Model Laid-Open No. 7-40016).

[0003] This type of exchangeable cutting edge drill is, for example, shown in FIG.
As shown in FIG. 5, in addition to a rod-shaped center drill P1 for processing the vicinity of the center of the hole, at least two plate-shaped outer peripheral cutting tips P2 and P3 for processing the vicinity of the outer periphery of the hole are provided. When fixing the outer peripheral edge tips P2 and P3 to the holder P4 of the drill, the screws P7 and P7 are inserted into tapered holes P5 and P6 provided through the side surfaces of the outer peripheral edge tips P2 and P3 in the thickness direction.
The outer peripheral blade tips P2 and P3 were screwed to the holder P4 by the screws P7 and P8. Also,
Other than this, there is one that clamps a plate-shaped outer peripheral blade tip to a holder using a wedge mechanism.

[0004]

However, when the outer peripheral cutting tips P2 and P3 are attached to the holder P4 as described above, in addition to the work of clamping the center drill P1 by screws, the outer peripheral cutting tips P2 and P3 are fixed. Since P3 is also independent, screwing work must be performed at least twice, and there is a problem in work efficiency.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a cutting insert and a cutting tool that can efficiently attach and replace a cutting insert.

[0006]

Means for Solving the Problems (1) The invention according to claim 1 for achieving the above object is a throw-away chip detachably attached to a tip end of a holder in a cutting tool, and A center drill for machining a portion corresponding to the center of rotation, and an outer peripheral edge tip for machining a portion corresponding to the periphery of the center of rotation. The center drill includes a shaft fixed to the holder, And a head provided on the tip end side of the shaft portion. The outer peripheral blade tip has a through hole (for example, a chip side through hole) through which the shaft portion of the center drill penetrates at the center of rotation. Further, the center drill and the outer peripheral cutting tip are locked to each other when the shaft portion of the center drill is inserted into the through hole of the outer peripheral cutting tip, and the outer peripheral cutting tip is dropped to the tip side. Prevent The throw-away tip, characterized in that a locking mechanism and gist.

The indexable insert of the present invention is used by combining a center drill and an outer peripheral tip integrally with each other by passing a shaft portion of a center drill through a through hole of the outer peripheral tip. In particular, this throwaway tip:
Since the locking mechanism is provided, when the shaft part of the center drill is inserted into the through hole of the outer peripheral tip, the center drill and the outer peripheral tip are locked to each other, so that the outer peripheral tip is moved toward the distal end side. , That is, the outer peripheral tip does not fall out of the center drill and does not fall to the tip side.

That is, in the present invention, once the shaft portion of the center drill is passed through the through hole of the outer blade tip, the outer blade tip does not fall off. For example, if the shaft portion of the center drill is fixed to the holder, Not only the center drill but also the outer peripheral tip can be fixed. Therefore, if this throw-away tip is used, it is extremely easy to attach and replace the throw-away tip to the holder.

According to a second aspect of the present invention, in the locking mechanism, the head of the center drill has a larger diameter than its own shaft portion and the through hole of the outer peripheral cutting tip has a smaller diameter than the head of the center drill. A feature of the indexable insert according to claim 1 is a configuration.

The present invention exemplifies a locking mechanism. Here, the head of the center drill is made larger in diameter than its own shaft, and the through hole of the outer peripheral tip is made smaller in diameter than the head of the center drill. In this case, the outer peripheral tip does not catch on the head, so that the outer peripheral tip does not fall off.

The invention according to claim 3 is characterized in that a drill-side taper portion having a diameter smaller toward the rear end side is provided at a rear end side of the head of the center drill, and at a front end side of a through hole of the outer peripheral tip. A tip-side tapered portion having a larger diameter at the tip end side is provided.

The present invention exemplifies a locking mechanism. In the present invention, when the shaft portion of the center drill is passed through the through hole of the outer peripheral tip, the drill side taper portion of the center drill and the tip side taper portion of the outer peripheral tip are securely locked, and the tip of the outer peripheral tip is formed. Dropping to the side can be prevented.

According to a fourth aspect of the present invention, in order to fix the center drill to the holder, a side surface of the shaft portion of the center drill is fixed to project from the holder side and press the shaft portion of the center drill. The indexable tip according to any one of claims 1 to 3, wherein a locking recess corresponding to the member (for example, a screw member) is provided.

In the present invention, since the locking recess is provided on the side surface of the shaft portion of the center drill, if the fixing member is projected from the holder side and fitted into the locking recess (for example, if the screw member is used). When the fixing member is locked in the locking concave portion, the shaft portion of the center drill can be pressed and fixed in a state where the fixing member is locked in the locking recess. In other words, by fixing the fixing member to the locking recess, the center drill can be fixed to the holder, and the outer peripheral tip is also fixed, so that the entire throw-away tip can be fixed to the holder.

According to a fifth aspect of the present invention, the center drill is urged toward the rear end side when the shaft portion of the center drill is fixed by the fixing member.
The present invention is characterized in that the indexable tip according to the fourth aspect is provided with an inclined portion that becomes shallower toward the rear end side.

In the present invention, an inclined portion which is shallower toward the rear end is provided at the rear end of the locking recess. Accordingly, when the fixing member is pushed vertically into the locking recess, for example (by rotating the screw member), so that the front end of the fixing member abuts on the inclined portion, the inclined portion (therefore, the center drill) is moved to the rear end. Receives a component force (biasing force) that is drawn into the side. Thereby, the center drill can be firmly fixed.

According to a sixth aspect of the present invention, there is provided a cutting tool comprising the indexable insert according to any one of the first to fifth aspects provided on a tip end side of the holder. In the present invention, the indexable insert having the above-described configuration is provided on the distal end side of the holder. Therefore, attachment or replacement of the throw-away tip is extremely easy.

For example, by simply loosening or tightening the fixing member attached to the holder and adjusting the locking state between the shaft portion of the center drill and the fixing member, it is possible to quickly attach or replace the indexable tip. it can. The gist of the invention of claim 7 is that the cutting tool is a rotary tool for cutting a work by rotating the throw-away tip and the holder.

The present invention exemplifies a cutting tool, and examples of the cutting tool include a rotary tool which rotates itself. The gist of the invention of claim 8 is the cutting tool according to claim 7, wherein the rotary tool is a cutting edge replaceable drill for replacing the indexable insert.

The present invention exemplifies a rotary tool, and examples of the rotary tool include a drill having a replaceable cutting edge. According to a ninth aspect of the present invention, the holder has a shaft fitting hole into which the rear end of the shaft portion of the center drill fits at the center of the shaft, and the shaft fitting from a side surface to the side surface of the holder. The cutting tool according to any one of claims 6 to 8, further comprising a side fixing hole which reaches the hole and in which the fixing member is arranged.

The present invention exemplifies the structure of the holder. In this holder, the rear end side of the shaft portion of the center drill is fitted into the shaft fitting hole, and a fixing member is disposed in the side surface fixing hole. Therefore, by protruding the fixing member toward the shaft center, the shaft portion of the center drill can be fixed.

The invention according to claim 10 is characterized in that the fixing member is a screw member, and the shaft portion of the center drill is pressed and fixed by screwing the fixing member. The gist is a cutting tool.

The present invention exemplifies a fixing member. Since a screw member (screw) is used as the fixing member, the center drill, and eventually the indexable tip, can be easily attached or replaced simply by tightening or loosening the screw member.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, examples (embodiments) of embodiments of a throw-away insert and a cutting tool according to the present invention will be described. (Example) a) First, as a cutting tool of the present example, a structure of a cutting edge replaceable drill will be described.

As shown in FIG. 1, the indexable drill 1 according to the present embodiment has a throw-away tip 7 comprising a center drill 3 and an outer peripheral tip 5, and a holder 9 having the throw-away tip 7 attached to the tip. It is composed of The throw-away tip 7 is a combination of the center drill 3 and the outer peripheral cutting tip 5. As will be described in detail later, the center drill 3 is pressed and fixed by a screw member (screw) 11, so that the throw-away tip 7 is pressed. It has a configuration in which the entire away chip 7 is fixed to the holder 9.

The material of the center drill 3 is high-speed tool steel, the material of the outer peripheral cutting tip 5 is superhard, and the material of the holder 9 is alloy steel. The blade diameter of the drill 1 is 22 mm. Hereinafter, each configuration will be described in more detail. As shown in FIG. 2, the center drill 3 is a rod-shaped member that cuts a portion corresponding to the rotation center of the replaceable drill 1 when processing a work (not shown). The head 15 has a cylindrical shaft 17 extending from an end face on the rear end side (right side in FIG. 2A) of the head 15. FIG. 2 (c)
Is a cross section taken along the line II ′ in FIG. 2B (that is, FIG. 2B).
(A cross section obtained by rotating the left side view of FIG. 1 by 30 degrees clockwise).

In the center drill 3, the outer diameter (φ10mm) of the head 15 is larger than the outer diameter (φ4mm) of the shaft portion 17. Further, on the rear end side of the head 15, there is provided a tapered portion whose diameter becomes smaller toward the rear end side, that is, a drill-side tapered portion 19 whose diameter becomes smaller by a taper of 60 degrees.
Further, a locking recess 21 into which the tip of the screw member 11 fits is formed on the side surface of the shaft portion 17, and the rear end of the locking recess 21 has an inclination of 25 degrees and becomes shallower toward the rear end. Is provided.

Next, as shown in FIG.
Is a plate-like member that cuts a portion corresponding to the periphery of the center of rotation of the center drill 3 and a side surface of a hole formed in the work when processing the work. To b. In addition, the outer peripheral blade tip 5
Has a slope of 5 degrees that is slightly receded toward the outer periphery.

A tip side through hole 25 into which the shaft portion 17 of the center drill 3 is inserted is formed at the center of the axis of the outer peripheral edge tip 5. On the tip side (left side in FIG. 3A) of the tip side through hole 25, a tapered portion having a larger diameter toward the tip side, that is, a tip side taper portion 29 having a larger diameter with a taper of 60 degrees is provided. Have been.

Then, as shown in FIG. 4, the center drill 3 and the outer peripheral tip 5 are combined to form a throw-away tip 7. That is, the shaft 17 of the center drill 3 is inserted into the tip side through hole 25 of the outer peripheral edge tip 5 by the arrow A.
The center drill 3 and the outer peripheral edge tip 5 are combined with each other, and at this time, the drill side taper portion 19 of the center drill 3 is seated on the tip side taper portion 29 of the outer peripheral edge tip 5. The center drill 3 and the outer peripheral tip 5 are integrally combined.

Here, the tip side taper portion 29 of the outer peripheral edge tip 5 and the drill side taper portion 19 of the center drill 3 are
Since both of them have a taper of 60 degrees, as shown in FIG. 4B, when the center drill 3 is pressed in the direction of arrow A and moves when the screw member 11 is tightened in the direction of arrow B, as shown in FIG. The entire surface of the tapered portion 29 is in contact and firmly engaged. FIG. 4 (b) is the same as FIG.
3B shows a part of the II ′ cross section.

The locking mechanism 30 is constituted by the tip-side tapered portion 29 of the outer peripheral edge tip 5 and the drill-side tapered portion 19 of the center drill 3. Next, as shown in FIG. 5, the holder 9 is provided with a long shank 31 and has a structure such as a groove 35 for fixing the throw-away tip 7 on the tip side (left side in the figure).

Specifically, as shown in FIG.
1 is provided with a groove 35 (having a substantially square cross section) perpendicularly crossing the axial center of the holder 9.
A holder-side through-hole 37 is formed at the center of 5 and penetrates the axis center of the holder 9. Incidentally, FIG.
The left side of (a) is shown.

The holder-side through-hole 37 is used as a coolant supply hole, and the tip of the holder-side through-hole 37 is slightly smaller than the rear end so that the shaft 17 of the center drill 3 can be fitted. A large-diameter shaft fitting hole 39 is provided.
In the holder-side through-hole 37, the branch through-holes 41 a and 4 (as coolant supply holes) branch midway.
1b, the branch through holes 41a, 41b
Are opened at the openings 43a and 43b on the distal end side of the holder 9.

Further, the holder 9 is provided with a side surface fixing hole 45 extending from the side surface to the shaft fitting hole 39 in a direction perpendicular to the center of the shaft. Since the side fixing holes 45 are for fixing the shaft 17 of the center drill 3 with the screw members 11, the inner peripheral surface thereof is threaded so that the screw members 11 can be screwed. It is.

The screw member 11 is a member whose entire side surface is threaded, and has the same outer diameter in the axial direction so that the entire member can enter into the side surface fixing hole 45 and be screwed. is there. b) Next, the procedure for assembling the drill 1 having the above-described structure and its operation will be described.

For example, as shown in FIG. 4, the shaft 17 of the center drill 3 is inserted into the through hole 25 on the tip side of the outer peripheral tip 5.
With the indexable tip 7 assembled through
As shown in FIG. 7, the indexable tip 7 is attached to the tip end side of the holder 9. FIG. 7 (c) shows the left side surface of FIG. 7 (a).

Specifically, with the indexable insert 7 assembled, the shaft 17 of the center drill 3 is attached to the holder 9.
Of the outer peripheral edge chip 5
Into the groove 35 of the holder 9. Next, the side fixing holes 4
The screw member 11 screwed into 5 is further tightened, and the tip of the screw member 11 is inserted into the locking recess 21 of the center drill 3 while pressing it. By this insertion, the tip of the screw member 11 comes into contact with the inclined portion 23 of the locking concave portion 21, so that the shaft portion 17 of the center drill 3 is pressed and moved in the direction of arrow A.

That is, by strongly tightening the screw member 11, the center drill 3 is pressed (biased) in the direction of arrow A.
Accordingly, the drill-side tapered portion 19 of the center drill 3 comes into contact with the tip-side tapered portion 29 of the outer peripheral edge tip 5, and the outer peripheral edge tip 5 is pressed in the direction of arrow A. Thereby,
The center drill 3 and the outer peripheral tip 5 are integrated, and the outer peripheral tip 5 is firmly fixed to the groove 35 on the distal end side of the holder 9.

As described above, in the present embodiment, the outer peripheral tip 7
The shaft portion 17 of the center drill 3 is passed through the through hole 25 on the tip side, the shaft portion 17 of the center drill 3 is fitted into the shaft fitting hole 39 of the holder 9, and the outer peripheral edge tip 5 is fitted into the groove portion 35 of the holder 9. In this state, just by tightening the screw member 11, the throw-away tip 7 including the center drill 3 and the outer peripheral cutting tip 5 can be firmly attached to the tip end side of the holder 9.

Therefore, when mounting or exchanging the throw-away tip 7, it is not necessary to turn many screws as in the prior art, and only one screw member 11 needs to be turned.
This has a remarkable effect that attachment and replacement of the throw-away tip 7 are extremely easy.

In this embodiment, since the inclined portion 23 is provided at the rear end side of the locking concave portion 21 of the shaft portion 17 of the center drill 3, when the screw member 11 is tightened, the center drill 3 is moved. As a result, the outer peripheral cutting tip 5 is pressed and fixed into the groove 35 by the center drill 3. Therefore, there is an advantage that the entire throw-away tip 7 is fixed more strongly and there is no backlash.

It should be noted that the present invention is not limited to the above-described embodiment at all, and it goes without saying that the present invention can be carried out in various modes without departing from the scope of the present invention. (1) For example, in the above-described embodiment, the inclined portion is provided in the locking concave portion, but the throw-away tip can be fixed even with a simple concave portion having no inclined portion.

(2) In the above embodiment, for example, FIG.
The screw member is tightened in the up and down direction so that its tip hits the locking recess of the shaft portion of the center drill. However, if the screw member can be locked in the locking recess and the center drill can be fixed, particularly There is no limitation. For example, a center drill can be fixed by providing a side fixing hole in the front-rear direction of the paper surface of FIG. 7A and inserting a screw member so that the screw member fits into the locking concave portion.

(3) In the above-described embodiment, the recess is a recess such as the locking recess. However, a through hole through which a screw member penetrates or fits may be used. (4) In the above embodiment, the center drill is fixed by the screw member, but a member other than the screw member may be used. For example, a simple bar may be inserted into the side fixing hole, and the bar may be fixed using, for example, screws or wedges.

(5) In the above embodiment, the rotary tool
Although the present invention has been described with reference to the example of the cutting edge replaceable drill, the present invention is also applicable to other rotary tools such as a cutter and an end mill. Further, the present invention can be applied not only to a rotary tool but also to a cutting tool that performs cutting by rotating a work.

[0047]

As described above in detail, according to the present invention, a throw-away tip is formed by passing the shaft portion of the center drill through the through hole of the outer peripheral cutting tip, and this throw-away tip is attached to the tip end side of the holder. For example, since the shaft portion of the center drill is fixed with a fixing member such as a screw member, the attachment and replacement of the throw-away tip are extremely easy, and the workability is high.

[Brief description of the drawings]

FIG. 1 is a front view showing a cutting edge replaceable drill according to an embodiment.

FIG. 2 shows a center drill, (a) is a front view thereof,
(B) is an explanatory view showing a part of a cross section taken along the line II ′ of (b).

FIG. 3 shows an outer peripheral edge tip, (a) is a front view thereof,
(B) is a bottom view thereof, and (c) is a left side thereof.

FIG. 4 (a) is an explanatory view showing a throw-away insert combining a center drill and an outer peripheral tip, and FIG. 4 (b).
FIG. 2 is an explanatory view showing a part of a section taken along the line II ′ of FIG.

FIG. 5 is a front view showing a holder of the replaceable drill.

6A and 6B are enlarged views of a part of the holder, FIG. 6A is an explanatory view showing a front surface thereof, FIG. 6B is an explanatory view showing a bottom surface thereof, and FIG. 6C is a left side view thereof.

FIG. 7 is an enlarged view of a part of a cutting edge replaceable drill,
(A) is an explanatory view showing the front face, (b) is an explanatory view showing the bottom face, and (c) is a left side view.

FIG. 8 is an explanatory diagram showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Drill with exchangeable cutting edge 3 ... Center drill 5 ... Outer edge tip 7 ... Indexable insert 9 ... Holder 11 ... Screw member 21 ... Locking concave part 23 ... Inclined part 19 ... Drill side taper part 25 ... Tip side through hole 29 ... Tip side taper part 30 ... Locking mechanism 35 ... Groove part 39 ... Shaft part fitting hole 45 ... Side part fixing hole

Claims (10)

[Claims] 1. A cutting insert which is detachably attached to a tip end of a holder of a cutting tool, wherein a center drill for machining a portion corresponding to a rotation center with respect to a work, and a center drill corresponding to a periphery of the rotation center. And an outer peripheral tip for processing a portion to be formed, wherein the center drill is fixed to the holder,
A head having a cutting edge and provided at a tip end side of the shaft portion, wherein the outer peripheral cutting edge tip has a through hole at a rotation center thereof, through which a shaft portion of the center drill passes. A locking mechanism that locks each other when the shaft portion of the center drill is inserted into the through-hole of the outer peripheral cutting tip to prevent the outer peripheral cutting tip from dropping to the tip side; A throwaway tip characterized by the provision of: 2. The locking mechanism according to claim 1, wherein the center drill has a head larger in diameter than its own shaft, and a through hole of the outer peripheral tip is smaller in diameter than the center drill. The throw-away tip according to claim 1, characterized in that: 3. A drill-side taper portion having a diameter smaller toward the rear end side is provided at a rear end side of the head portion of the center drill, and a diameter is set closer to the front end side of a through hole of the outer peripheral edge tip. The throw-away tip according to claim 2, wherein a tip-side tapered portion having a larger diameter is provided. 4. In order to fix the center drill to the holder, a side surface side of a shaft portion of the center drill is provided with a fixing member protruding from the holder side and pressing the shaft portion of the center drill. The indexable tip according to any one of claims 1 to 3, wherein a stop recess is provided. 5. The rear end side of the locking concave portion is shallower toward the rear end side so that the center drill can be biased toward the rear end side when the shaft portion of the center drill is fixed by the fixing member. The indexable tip according to claim 4, wherein an inclined portion is provided. 6. A cutting tool comprising the indexable insert according to any one of claims 1 to 5 provided on a tip end side of the holder. 7. The cutting tool according to claim 6, wherein the cutting tool is a rotary tool that cuts a work by rotating the indexable tip and the holder. 8. The cutting tool according to claim 7, wherein the rotary tool is a cutting edge replaceable drill that replaces the indexable insert. 9. The holder has a shaft insertion hole into which the rear end of the shaft of the center drill is inserted at the center of the shaft, and a side surface of the holder is provided with a shaft insertion hole from a side surface. The cutting tool according to any one of claims 6 to 8, further comprising a side fixing hole that reaches the fixing member. 10. The cutting tool according to claim 9, wherein the fixing member is a screw member, and the fixing member is screwed in to fix the shaft of the center drill.